javadoc
Running
Synopsis
javadoc [ options ] [ packagenames ] [ sourcefilenames ] [ -subpackages pkg1:pkg2:... ] [ @argfiles ]
Arguments can
be in any order. See processing of Source Files for details
on how the Javadoc tool determines which
".java" files to process.
options
Command-line options, as
specified in this document. To see a typical use of javadoc
options, see Real-World Example.
packagenames
A series of names of packages,
separated by spaces, such as
java.lang java.lang.reflect java.awt. You
must separately specify each package you want to document.
Wildcards are not allowed; use -subpackages for
recursion. The Javadoc tool uses -sourcepath to
look for these package names. See Example -
Documenting One or More Packages
sourcefilenames
A series of source file names,
separated by spaces, each of which can begin with a path and
contain a wildcard such as asterisk (*). The Javadoc tool
will process every file whose name ends with
".java", and whose name, when stripped of that
suffix, is actually a legal class name (see
Identifiers @
http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#40625).
Therefore, you can name files with dashes (such as
X-Buffer), or other illegal characters, to
prevent them from being documented. This is useful for test
files and template files The path that precedes the source
file name determines where javadoc will look for the file.
(The Javadoc tool does not use
-sourcepath to look for these source file
names.) Relative paths are relative to the current
directory, so passing in Button.java is identical to
./Button.java. A source file name with an absolute
path and a wildcard, for example, is
/home/src/java/awt/Graphics*.java. See
Example - Documenting One or More Classes.
You can also mix packagenames and sourcefilenames, as in
Example - Documenting Both Packages and
Classes
-subpackages
pkg1:pkg2:...
Generates documentation from
source files in the specified packages and recursively in
their subpackages. An alternative to supplying packagenames
or sourcefilenames.
@argfiles
One or more files that contain
a list of Javadoc options, packagenames and sourcefilenames
in any order. Wildcards (*) and -J options are
not allowed in these files.
add an example, a script, a trick and tips
examples
source
mkdir javadoc;
javadoc -d javadoc com.multicorebsp.core
description
The
Javadoc tool parses the declarations and
documentation comments in a set of Java source files and
produces a corresponding set of HTML pages describing (by
default) the public and protected classes, nested classes
(but not anonymous inner classes), interfaces, constructors,
methods, and fields. You can use it to generate the API
(Application Programming Interface) documentation or the
implementation documentation for a set of source files.
You can run the
Javadoc tool on entire packages, individual source files, or
both. When documenting entire packages, you can either use
-subpackages for traversing recursively down
from a top-level directory, or pass in an explicit
list of package names. When documenting individual source
files, you pass in a list of source (.java)
filenames. Examples are given at the end of this document.
How Javadoc processes source files is covered next.
Processing
of source files
The Javadoc tool processes files that end in
".java" plus other files described under
Source Files. If you run the Javadoc tool by explicitly
passing in individual source filenames, you can determine
exactly which ".java" files are processed.
However, that is not how most developers want to work, as it
is simpler to pass in package names. The Javadoc tool can be
run three ways without explicitly specifying the source
filenames. You can (1) pass in package names, (2) use
-subpackages, and (3) use wildcards with source
filenames (*.java). In these cases, the Javadoc tool
processes a ".java" file only if it
fulfills all of the following requirements:
o
Its name, after stripping off the
".java" suffix, is actually a legal class
name (see Identifiers @
http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#40625
for legal characters)
o
Its directory path relative to
the root of the source tree is actually a legal package name
(after converting its separators to dots)
o
Its package statement contains the legal package name
(specified in the previous bullet)
Processing
of links - During a run, the Javadoc tool
automatically adds cross-reference links to package,
class and member names that are being documented as part of
that run. Links appear in several places:
o
Declarations (return types,
argument types, field types)
o
"See Also" sections generated from @see
tags
o
In-line text generated from {@link}
tags
o
Exception names generated from @throws tags
o
"Specified by" links to members in interfaces
and "Overrides" links to members in classes
o
Summary tables listing packages, classes and members
o
Package and class inheritance trees
o
The index
You can add
hyperlinks to existing text for classes not included on the
command line (but generated separately) by way of the
-link and -linkoffline
options.
Other
processing details - The Javadoc tool produces one
complete document each time it is run; it cannot do
incremental builds -- that is, it cannot modify
or directly incorporate results from previous runs of
the Javadoc tool. However, it can link to results from other
runs, as just mentioned.
As implemented,
the Javadoc tool requires and relies on the java compiler to
do its job. The Javadoc tool calls part of javac to
compile the declarations, ignoring the member
implementation. It builds a rich internal representation of
the classes, including the class hierarchy, and
"use" relationships, then generates the HTML from
that. The Javadoc tool also picks up user-supplied
documentation from documentation comments in the source
code.
In fact, the
Javadoc tool will run on .java source files that are
pure stub files with no method bodies. This means you can
write documentation comments and run the Javadoc tool in the
earliest stages of design while creating the API, before
writing the implementation.
Relying on the
compiler ensures that the HTML output corresponds exactly
with the actual implementation, which may rely on implicit,
rather than explicit, source code. For example, the Javadoc
tool documents default constructors @
http://java.sun.com/docs/books/jls/second_edition/html/names.doc.html#36154
(section 8.6.7 of Java Language Specification) that
are present in the .class files but not in the source
code.
In many cases,
the Javadoc tool allows you to generate documentation for
source files whose code is incomplete or erroneous. This is
a benefit that enables you to generate documentation before
all debugging and troubleshooting is done. For example,
according to the Java Language Specification, a class
that contains an abstract method should itself be declared
abstract. The Javadoc tool does not check for this, and
would proceed without a warning, whereas the javac compiler
stops on this error. The Javadoc tool does do some primitive
checking of doc comments. Use the DocCheck doclet to check
the doc comments more thoroughly.
When the
Javadoc tool builds its internal structure for the
documentation, it loads all referenced classes. Because of
this, the Javadoc tool must be able to find all referenced
classes, whether bootstrap classes, extensions, or user
classes. For more about this, see How Classes Are Found.
Generally speaking, classes you create must either be loaded
as an extension or in the Javadoc tool’s class
path.
Javadoc
Doclets
You can customize the content and format of the Javadoc
tool’s output by using doclets. The Javadoc tool has a
default "built-in" doclet, called the
standard doclet, that generates HTML-formatted API
documentation. You can modify or subclass the standard
doclet, or write your own doclet to generate HTML, XML, MIF,
RTF or whatever output format you’d like. Information
about doclets and their use is at the following
locations:
o
Javadoc Doclets
o
The -doclet command-line option
When a custom
doclet is not specified with the -doclet
command line option, the Javadoc tool will use the default
standard doclet. The javadoc tool has several command line
options that are available regardless of which doclet is
being used. The standard doclet adds a supplementary set of
command line options. Both sets of options are described
below in the options section.
Related
Documentation and Doclets
o
Javadoc Enhancements for details
about improvements added in Javadoc.
o
Javadoc FAQ @
http://java.sun.com/j2se/javadoc/faq/index.html
for answers to common questions, information about
Javadoc-related tools, and workarounds for bugs.
o
How to Write Doc Comments for
Javadoc @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html
for more information about Sun conventions for writing
documentation comments.
o
Requirements for Writing API
Specifications @
http://java.sun.com/j2se/javadoc/writingapispecs/index.html
- Standard requirements used when writing the Java 2
Platform Specification. It can be useful whether you are
writing API specifications in source file documentation
comments or in other formats. It covers requirements for
packages, classes, interfaces, fields and methods to satisfy
testable assertions.
o
Documentation Comment
Specification @
http://java.sun.com/docs/books/jls/first_edition/html/18.doc.html
- The original specification on documentation
comments, Chapter 18, Documentation Comments, in the Java
Language Specification, First Edition, by James Gosling,
Bill Joy, and Guy Steele. (This chapter was removed from the
second edition.)
http://java.sun.com/javadoc/doccheck
- Checks doc comments in source files and generates a
report listing the errors and irregularities it finds. It is
part of the Sun Doc Check Utilities.
http://java.sun.com/javadoc/mifdoclet
- Can automate the generation of API documentation in
MIF, FrameMaker and PDF formats. MIF is Adobe
FrameMaker’s interchange format.
Terminology
The terms documentation comment, doc comment,
main description, tag, block tag, and
in-line tag are described at Documentation
Comments. These other terms have specific meanings within
the context of the Javadoc tool:
generated document
The document generated by the
javadoc tool from the doc comments in Java source code. The
default generated document is in HTML and is created by the
standard doclet.
name
A name of a program element
written in the Java Language -- that is, the
name of a package, class, interface, field, constructor or
method. A name can be fully-qualified, such as
java.lang.String.equals(java.lang.Object), or
partially-qualified, such as
equals(Object).
documented classes
The classes and interfaces for
which detailed documentation is generated during a javadoc
run. To be documented, the source files must be available,
their source filenames or package names must be passed into
the javadoc command, and they must not be filtered out by
their access modifier (public, protected,
package-private or private). We also refer to these as
the classes included in the javadoc output, or the
included classes.
included classes
Classes and interfaces whose
details are documented during a run of the Javadoc tool.
Same as documented classes.
excluded classes
Classes and interfaces whose
details are not documented during a run of the
Javadoc tool.
referenced classes
The classes and interfaces that
are explicitly referred to in the definition
(implementation) or doc comments of the documented classes
and interfaces. Examples of references include return type,
parameter type, cast type, extended class, implemented
interface, imported classes, classes used in method bodies,
@see, {@link}, {@linkplain}, and {@inheritDoc} tags. (Notice
this definition has changed since 1.3 @
http://java.sun.com/j2se/1.3/docs/tooldocs/solaris/javadoc.html#referencedclasses.)
When the Javadoc tool is run, it should load into memory all
of the referenced classes in javadoc’s bootclasspath
and classpath. (The Javadoc tool prints a "Class not
found" warning for referenced classes not found.) The
Javadoc tool can derive enough information from the .class
files to determine their existence and the
fully-qualified names of their members.
external referenced classes
The referenced classes whose
documentation is not being generated during a javadoc run.
In other words, these classes are not passed into the
Javadoc tool on the command line. Links in the generated
documentation to those classes are said to be external
references or external links. For example, if you
run the Javadoc tool on only the java.awt package,
then any class in java.lang, such as Object,
is an external referenced class. External referenced classes
can be linked to using the -link and
-linkoffline options. An important property of
an external referenced class is that its source comments are
normally not available to the Javadoc run. In this case,
these comments cannot be inherited.
options
The javadoc
tool uses doclets to determine its output. The Javadoc tool
uses the default standard doclet unless a custom doclet is
specified with the -doclet option. The Javadoc tool
provides a set of command-line options that can be
used with any doclet -- these options are
described below under the sub-heading Javadoc Options.
The standard doclet provides an additional set of
command-line options that are described below under
the sub-heading Options Provided by the Standard
Doclet. All option names are case-insensitive, though
their arguments can be case-sensitive.
The options
are:
Options shown
in italic are the Javadoc core options, which are
provided by the front end of the Javadoc tool and are
available to all doclets. The standard doclet itself
provides the non-italic options.
Javadoc
Options
-overview
path/filename
Specifies that javadoc should
retrieve the text for the overview documentation from the
"source" file specified by path/filename
and place it on the Overview page
(overview-summary.html). The
path/filename is relative to the
-sourcepath.
While you can
use any name you want for filename and place it
anywhere you want for path, a typical thing to do is
to name it overview.html and place it in the source
tree at the directory that contains the topmost package
directories. In this location, no path is needed when
documenting packages, since -sourcepath will
point to this file. For example, if the source tree for the
java.lang package is /src/classes/java/lang/,
then you could place the overview file at
/src/classes/overview.html. See Real World
Example.
For information
about the file specified by path/filename, see
overview comment file.
Note that the
overview page is created only if you pass into javadoc two
or more package names. For further explanation, see HTML
Frames.)
The title on
the overview page is set by -doctitle.
-public
Shows only public classes and
members.
-protected
Shows only protected and public
classes and members. This is the default.
-package
Shows only package, protected,
and public classes and members.
-private
Shows all classes and
members.
-help
Displays the online help, which
lists these javadoc and doclet command line options.
-doclet class
Specifies the class file that
starts the doclet used in generating the documentation. Use
the fully-qualified name. This doclet defines the
content and formats the output. If the
-doclet option is not used, javadoc uses
the standard doclet for generating the default HTML format.
This class must contain the start(Root) method. The
path to this starting class is defined by the
-docletpath option.
For example, to
call the MIF doclet, use:
-doclet com.sun.tools.doclets.mif.MIFDoclet
For full,
working examples of running a particular doclet, see
Running the MIF Doclet @
http://java.sun.com/j2se/javadoc/mifdoclet/docs/mifdoclet.html#runningmifdoclet.
-docletpath classpathlist
Specifies the path to the
doclet starting class file (specified with the
-doclet option) and any jar files it depends
on. If the starting class file is in a jar file, then this
specifies the path to that jar file, as shown in the example
below. You can specify an absolute path or a path relative
to the current directory. If classpathlist contains
multiple paths or jar files, they should be separated with a
colon (:) on Solaris and a semi-colon (;) on Windows.
This option is not necessary if the doclet starting class is
already in the search path.
Example of path
to jar file that contains the starting doclet class file.
Notice the jar filename is included.
-docletpath /home/user/mifdoclet/lib/mifdoclet.jar
Example of path to starting doclet class file. Notice the
class filename is omitted.
-docletpath
/home/user/mifdoclet/classes/com/sun/tools/doclets/mif/
For full, working examples of running a particular doclet,
see Running the MIF Doclet @
http://java.sun.com/j2se/javadoc/mifdoclet/docs/mifdoclet.html#runningmifdoclet.
-1.1
This feature has been
removed from Javadoc 1.4. There is no replacement for it.
This option created documentation with the appearance and
functionality of documentation generated by Javadoc 1.1 (it
never supported nested classes). If you need this option,
use Javadoc 1.2 or 1.3 instead.
-source release
Specifies the version of source
code accepted. The following values for release are
allowed:
Use the value
of release corresponding to that used when compiling
the code with javac.
-sourcepath sourcepathlist
Specifies the search paths for
finding source files (.java) when passing package
names or -subpackages into the javadoc
command. The sourcepathlist can contain multiple
paths by separating them with a colon (:). The
Javadoc tool will search in all subdirectories of the
specified paths. Note that this option is not only used to
locate the source files being documented, but also to find
source files that are not being documented but whose
comments are inherited by the source files being
documented.
Note that you
can use the -sourcepath option only when
passing package names into the javadoc command
-- it will not locate .java files passed
into the javadoc command. (To locate .java
files, cd to that directory or include the path ahead of
each file, as shown at Documenting One or More Classes.) If
-sourcepath is omitted, javadoc uses the class
path to find the source files (see -classpath).
Therefore, the default -sourcepath is the value of
class path. If -classpath is omitted and you are
passing package names into javadoc, it looks in the current
directory (and subdirectories) for the source files.
Set
sourcepathlist to the root directory of the source
tree for the package you are documenting. For example,
suppose you want to document a package called
com.mypackage whose source files are located at:
/home/user/src/com/mypackage/*.java
In this case you would specify the sourcepath to
/home/user/src, the directory that contains
com/mypackage, and then supply the package name
com.mypackage:
% javadoc -sourcepath /home/user/src/
com.mypackage
This is easy to remember by noticing that if you concatenate
the value of sourcepath and the package name together and
change the dot to a slash "/", you end up with the
full path to the package:
/home/user/src/com/mypackage.
To point to two
source paths:
% javadoc -sourcepath /home/user1/src:/home/user2/src
com.mypackage
-classpath classpathlist
Specifies the paths where
javadoc will look for referenced classes (.class
files) -- these are the documented classes plus
any classes referenced by those classes. The
classpathlist can contain multiple paths by
separating them with a colon (:). The Javadoc tool
will search in all subdirectories of the specified paths.
Follow the instructions in class path documentation for
specifying classpathlist.
If
-sourcepath is omitted, the Javadoc tool uses
-classpath to find the source files as well as
class files (for backward compatibility). Therefore, if you
want to search for source and class files in separate paths,
use both -sourcepath and
-classpath.
For example, if
you want to document com.mypackage, whose source
files reside in the directory
/home/user/src/com/mypackage, and if this package
relies on a library in /home/user/lib, you would
specify:
% javadoc -classpath /home/user/lib -sourcepath
/home/user/src com.mypackage
As with other tools, if you do not specify
-classpath, the Javadoc tool uses the CLASSPATH
environment variable, if it is set. If both are not set, the
Javadoc tool searches for classes from the current
directory.
For an
in-depth description of how the Javadoc tool uses
-classpath to find user classes as it relates
to extension classes and bootstrap classes, see How Classes
Are Found.
As a special
convenience, a class path element containing a basename of
* is considered equivalent to specifying a list of
all the files in the directory with the extension
.jar or .JAR (a java program cannot tell the
difference between the two invocations).
For example, if directory foo contains a.jar
and b.JAR, then the class path element foo/*
is expanded to a A.jar:b.JAR, except that the order
of jar files is unspecified. All jar files in the specified
directory, even hidden ones, are included in the list. A
classpath entry consisting simply of * expands to a
list of all the jar files in the current directory. The
CLASSPATH environment variable, where defined, will
be similarly expanded. Any classpath wildcard expansion
occurs before the Java virtual machine is started
-- no Java program will ever see unexpanded
wildcards except by querying the environment. For example;
by invoking System.getenv("CLASSPATH").
-subpackages package1:package2:...
Generates documentation from
source files in the specified packages and recursively in
their subpackages. This option is useful when adding new
subpackages to the source code, as they are automatically
included. Each package argument is any
top-level subpackage (such as java) or fully
qualified package (such as javax.swing) that does not
need to contain source files. Arguments are separated by
colons (on all operating systmes). Wildcards are not needed
or allowed. Use -sourcepath to specify where to
find the packages. This option is smart about not processing
source files that are in the source tree but do not belong
to the packages, as described at processing of source
files.
For example:
% javadoc -d docs -sourcepath /home/user/src
-subpackages java:javax.swing
This command generates documentation for packages named
"java" and "javax.swing" and all their
subpackages.
You can use
-subpackages in conjunction with
-exclude to exclude specific packages.
-exclude packagename1:packagename2:...
Unconditionally excludes the
specified packages and their subpackages from the list
formed by -subpackages. It excludes those
packages even if they would otherwise be included by some
previous or later -subpackages option. For
example:
% javadoc -sourcepath /home/user/src
-subpackages java -exclude
java.net:java.lang
would include java.io, java.util, and
java.math (among others), but would exclude packages
rooted at java.net and java.lang. Notice this
excludes java.lang.ref, a subpackage of
java.lang).
-bootclasspath
classpathlist
Specifies the paths where the
boot classes reside. These are nominally the Java platform
classes. The bootclasspath is part of the search path the
Javadoc tool will use to look up source and class files. See
How Classes Are Found. for more details. Separate
directories in classpathlist with colons (:).
-extdirs
dirlist
Specifies the directories where
extension classes reside. These are any classes that use the
Java Extension mechanism. The extdirs is part of the search
path the Javadoc tool will use to look up source and class
files. See -classpath (above) for more details.
Separate directories in dirlist with colons (:).
-verbose
Provides more detailed messages
while javadoc is running. Without the verbose option,
messages appear for loading the source files, generating the
documentation (one message per source file), and sorting.
The verbose option causes the printing of additional
messages specifying the number of milliseconds to parse each
java source file.
-quiet
Shuts off non-error and
non-warning messages, leaving only the warnings and
errors appear, making them easier to view. Also suppresses
the version string.
-breakiterator
Uses the internationalized
sentence boundary of java.text.BreakIterator to
determine the end of the first sentence for English (all
other locales already use BreakIterator), rather than
an English language, locale-specific algorithm. By
first sentence, we mean the first sentence in the
main description of a package, class or member. This
sentence is copied to the package, class or member summary,
and to the alphabetic index.
From JDK 1.2
forward, the BreakIterator class is already used to
determine the end of sentence for all languages but English.
Therefore, the -breakiterator option has no
effect except for English from 1.2 forward. English has its
own default algorithm:
o
English default sentence-break algorithm -
Stops at a period followed by a space or a HTML block tag,
such as <P>.
o
Breakiterator sentence-break algorithm - In
general, stops at a period, question mark or exclamation
mark followed by a space if the next word starts with a
capital letter. This is meant to handle most abbreviations
(such as "The serial no. is valid", but
won’t handle "Mr. Smith"). Doesn’t
stop at HTML tags or sentences that begin with numbers or
symbols. Stops at the last period in
"../filename", even if embedded in an HTML
tag.
NOTE: We have
removed from 1.5.0 the breakiterator warning messages that
were in 1.4.x and have left the default sentence-break
algorithm unchanged. That is, the -breakiterator
option is not the default in 1.5.0, nor do we expect it to
become the default. This is a reversal from our former
intention that the default would change in the "next
major release" (1.5.0). This means if you have not
modified your source code to eliminate the breakiterator
warnings in 1.4.x, then you don’t have to do anything,
and the warnings go away starting with 1.5.0. The reason for
this reversal is because any benefit to having breakiterator
become the default would be outweighed by the incompatible
source change it would require. We regret any extra work and
confusion this has caused.
-locale
language_country_variant
Important
- The -locale option must be placed
ahead (to the left) of any options provided by the
standard doclet or any other doclet. Otherwise, the
navigation bars will appear in English. This is the only
command-line option that is order-dependent.
Specifies the
locale that javadoc uses when generating documentation. The
argument is the name of the locale, as described in
java.util.Locale documentation, such as en_US
(English, United States) or en_US_WIN (Windows
variant).
Specifying a
locale causes javadoc to choose the resource files of that
locale for messages (strings in the navigation bar, headings
for lists and tables, help file contents, comments in
stylesheet.css, and so forth). It also specifies the sorting
order for lists sorted alphabetically, and the sentence
separator to determine the end of the first sentence. It
does not determine the locale of the doc comment text
specified in the source files of the documented classes.
-encoding name
Specifies the encoding name of
the source files, such as EUCJIS/SJIS. If this option
is not specified, the platform default converter is
used.
Also see
-docencoding and -charset.
-Jflag
Passes flag directly to
the runtime system java that runs javadoc. Notice there must
be no space between the J and the flag. For
example, if you need to ensure that the system sets aside 32
megabytes of memory in which to process the generated
documentation, then you would call the -Xmx
option of java as follows (-Xms is optional, as
it only sets the size of initial memory, which is useful if
you know the minimum amount of memory required):
% javadoc -J-Xmx32m -J-Xms32m
com.mypackage
To tell what version of javadoc you are using, call the
"-version" option of java:
% javadoc -J-version
java version "1.2"
Classic VM (build JDK-1.2-V, green threads,
sunwjit)
(The version number of the standard doclet appears in its
output stream.)
Options
Provided by the Standard Doclet
-d directory
Specifies the destination
directory where javadoc saves the generated HTML files. (The
"d" means "destination.") Omitting this
option causes the files to be saved to the current
directory. The value directory can be absolute, or
relative to the current working directory. As of 1.4, the
destination directory is automatically created when javadoc
is run.
For example,
the following generates the documentation for the package
com.mypackage and saves the results in the
/home/user/doc/ directory:
% javadoc -d /home/user/doc com.mypackage
-use
Includes one "Use"
page for each documented class and package. The page
describes what packages, classes, methods, constructors and
fields use any API of the given class or package. Given
class C, things that use class C would include subclasses of
C, fields declared as C, methods that return C, and methods
and constructors with parameters of type C.
For example,
let’s look at what might appear on the "Use"
page for String. The getName() method in the
java.awt.Font class returns type String.
Therefore, getName() uses String, and you will
find that method on the "Use" page for
String.
Note that this
documents only uses of the API, not the implementation. If a
method uses String in its implementation but does not
take a string as an argument or return a string, that is not
considered a "use" of String.
You can access
the generated "Use" page by first going to the
class or package, then clicking on the "Use" link
in the navigation bar.
-version
Includes the @version text in
the generated docs. This text is omitted by default. To tell
what version of the Javadoc tool you are using, use the
-J-version option.
-author
Includes the @author text in
the generated docs.
-splitindex
Splits the index file into
multiple files, alphabetically, one file per letter, plus a
file for any index entries that start with
non-alphabetical characters.
-windowtitle
title
Specifies the title to be
placed in the HTML <title> tag. This appears in the
window title and in any browser bookmarks (favorite places)
that someone creates for this page. This title should not
contain any HTML tags, as the browser will not properly
interpret them. Any internal quotation marks within
title may have to be escaped. If -windowtitle
is omitted, the Javadoc tool uses the value of
-doctitle for this option.
% javadoc -windowtitle "Java 2 Platform"
com.mypackage
-doctitle title
Specifies the title to be
placed near the top of the overview summary file. The title
will be placed as a centered, level-one heading
directly beneath the upper navigation bar. The title
may contain html tags and white space, though if it does, it
must be enclosed in quotes. Any internal quotation marks
within title may have to be escaped.
% javadoc -doctitle "Java<sup><font
size=\"-2\">TM</font></sup>"
com.mypackage
-title title
This option no longer
exists. It existed only in Beta versions of Javadoc 1.2.
It has been renamed to -doctitle. This option
is being renamed to make it clear that it defines the
document title rather than the window title.
-header header
Specifies the header text to be
placed at the top of each output file. The header will be
placed to the right of the upper navigation bar.
header may contain HTML tags and white space, though
if it does, it must be enclosed in quotes. Any internal
quotation marks within header may have to be escaped.
% javadoc -header "<b>Java 2 Platform
</b><br>v1.4" com.mypackage
-footer footer
Specifies the footer text to be
placed at the bottom of each output file. The footer will be
placed to the right of the lower navigation bar.
footer may contain html tags and white space, though
if it does, it must be enclosed in quotes. Any internal
quotation marks within footer may have to be
escaped.
-bottom text
Specifies the text to be placed
at the bottom of each output file. The text will be placed
at the bottom of the page, below the lower navigation bar.
The text may contain HTML tags and white space,
though if it does, it must be enclosed in quotes. Any
internal quotation marks within text may have to be
escaped.
-link extdocURL
Creates links to existing
javadoc-generated documentation of external referenced
classes. It takes one argument:
o
extdocURL is the absolute or relative URL
of the directory containing the external
javadoc-generated documentation you want to link to.
Examples are shown below. The package-list file must
be found in this directory (otherwise, use
-linkoffline). The Javadoc tool reads the
package names from the package-list file and
then links to those packages at that URL. When the Javadoc
tool is run, the extdocURL value is copied literally
into the <A HREF> links that are created.
Therefore, extdocURL must be the URL to the
directory, not to a file.
You can use an
absolute link for extdocURL to enable your docs to
link to a document on any website, or can use a relative
link to link only to a relative location. If relative, the
value you pass in should be the relative path from the
destination directory (specified with -d) to
the directory containing the packages being linked to.
When specifying
an absolute link you normally use an http: link.
However, if you want to link to a file system that has no
web server, you can use a file: link --
however, do this only if everyone wanting to access the
generated documentation shares the same file system.
In all cases,
and on all operating systems, you should use a forward slash
as the separator, whether the URL is absolute or relative,
and "http:" or "file:" based (as
specified in the URL Memo @
http://www.ietf.org/rfc/rfc1738.txt).
Absolute http: based link:
-link
http://<host>/<directory>/<directory>/.../<name>
Absolute file: based link:
-link
file://<host>/<directory>/<directory>/.../<name>
Relative link:
-link
<directory>/<directory>/.../<name>
You can specify
multiple -link options in a given javadoc run
to link to multiple documents. Choosing between
-linkoffline and -link:
Use -link:
o
when using a relative path to the external API document,
or
o
when using an absolute URL to the external API document,
if your shell allows a program to open a connection to that
URL for reading.
Use
-linkoffline:
o
when using an absolute URL to
the external API document, if your shell does not
allow a program to open a connection to that URL for
reading. This can occur if you are behind a firewall and the
document you want to link to is on the other side.
Example
using absolute links to the external docs -
Let’s say you want to link to the java.lang,
java.io and other Java 2 Platform packages at
http://java.sun.com/j2se/1.5.0/docs/api @
http://java.sun.com/j2se/1.5.0/docs/api, The following
command generates documentation for the package
com.mypackage with links to the Java 2 Platform
packages. The generated documentation will contain links to
the Object class, for example, in the class trees.
(Other options, such as -sourcepath and
-d, are not shown.)
% javadoc -link
http://java.sun.com/j2se/1.5.0/docs/api com.mypackage
Example using relative links to the external docs
- Let’s say you have two packages whose docs are
generated in different runs of the Javadoc tool, and those
docs are separated by a relative path. In this example, the
packages are com.apipackage, an API, and
com.spipackage, an SPI (Service Provide Interface).
You want the documentation to reside in
docs/api/com/apipackage and
docs/spi/com/spipackage. Assuming the API package
documentation is already generated, and that docs is
the current directory, you would document the SPI package
with links to the API documentation by running:
% javadoc -d ./spi -link ../api
com.spipackage
Notice the
-link argument is relative to the destination
directory (docs/spi).
Details
- The -link option enables you to link to
classes referenced to by your code but not documented
in the current javadoc run. For these links to go to valid
pages, you must know where those HTML pages are located, and
specify that location with extdocURL. This allows,
for instance, third party documentation to link to
java.* documentation on
http://java.sun.com.
Omit the
-link option for javadoc to create links only
to API within the documentation it is generating in the
current run. (Without the -link option, the
Javadoc tool does not create links to documentation for
external references, because it does not know if or where
that documentation exists.)
This option can
create links in several places in the generated
documentation.
Another use is
for cross-links between sets of packages: Execute
javadoc on one set of packages, then run javadoc again on
another set of packages, creating links both ways between
both sets.
How a Class
Must be Referenced - For a link to an external
referenced class to actually appear (and not just its text
label), the class must be referenced in the following way.
It is not sufficient for it to be referenced in the body of
a method. It must be referenced in either an import
statement or in a declaration. Here are examples of how the
class java.io.File can be referenced:
o
In any kind of import
statement: by wildcard import, import explicitly by name, or
automatically import for java.lang.*. For example,
this would suffice:
import java.io.*;
In 1.3.x and 1.2.x, only an explicit import by name works
-- a wildcard import statement does not work,
nor does the automatic import java.lang.*.
void foo(File f) {}
The reference and be in the return type or parameter type of
a method, constructor, field, class or interface, or in an
implements, extends or throws
statement.
An important
corollary is that when you use the -link
option, there may be many links that unintentionally do not
appear due to this constraint. (The text would appear
without a hypertext link.) You can detect these by the
warnings they emit. The most innocuous way to properly
reference a class and thereby add the link would be to
import that class, as shown above.
Package
List - The -link option requires that
a file named package-list, which is generated
by the Javadoc tool, exist at the URL you specify with
-link. The package-list file is a
simple text file that lists the names of packages documented
at that location. In the earlier example, the Javadoc tool
looks for a file named package-list at the
given URL, reads in the package names and then links to
those packages at that URL.
For example,
the package list for the Java 2 Platform 5.0 API is located
at
http://java.sun.com/j2se/1.5.0/docs/api/package-list
@
http://java.sun.com/j2se/1.5.0/docs/api/package-list.
and starts out as follows:
java.applet
java.awt
java.awt.color
java.awt.datatransfer
java.awt.dnd
java.awt.event
java.awt.font
etc.
When javadoc is
run without the -link option, when it
encounters a name that belongs to an external referenced
class, it prints the name with no link. However, when the
-link option is used, the Javadoc tool searches
the package-list file at the specified
extdocURL location for that package name. If it finds
the package name, it prefixes the name with
extdocURL.
In order for
there to be no broken links, all of the documentation for
the external references must exist at the specified URLs.
The Javadoc tool will not check that these pages exist
-- only that the package-list exists.
Multiple
Links - You can supply multiple -link
options to link to any number of external generated
documents. Javadoc 1.2 has a known bug which prevents
you from supplying more than one -link command.
This was fixed in 1.2.2.
Specify a
different link option for each external document to link to:
%
javadoc -link extdocURL1
-link extdocURL2 ...
-link extdocURLn
com.mypackage
where
extdocURL1, extdocURL2, ...
extdocURLn point respectively to the roots of
external documents, each of which contains a file named
package-list.
Cross-links
- Note that "bootstrapping" may be required
when cross-linking two or more documents that have not
previously been generated. In other words, if
package-list does not exist for either
document, when you run the Javadoc tool on the first
document, the package-list will not yet exist
for the second document. Therefore, to create the external
links, you must re-generate the first document after
generating the second document.
In this case,
the purpose of first generating a document is to create its
package-list (or you can create it by hand it
if you’re certain of the package names). Then generate
the second document with its external links. The Javadoc
tool prints a warning if a needed external
package-list file does not exist.
-linkoffline extdocURL packagelistLoc
This option is a variation of
-link; they both create links to
javadoc-generated documentation for external
referenced classes. Use the -linkoffline option
when linking to a document on the web when the Javadoc tool
itself is "offline" -- that is, it
cannot access the document through a web connection.
More
specifically, use -linkoffline if the external
document’s package-list file is not
accessible or does not exist at the extdocURL
location but does exist at a different location, which can
be specified by packageListLoc (typically local).
Thus, if extdocURL is accessible only on the World
Wide Web, -linkoffline removes the constraint
that the Javadoc tool have a web connection when generating
the documentation.
Another use is
as a "hack" to update docs: After you have run
javadoc on a full set of packages, then you can run javadoc
again on onlya smaller set of changed packages, so that the
updated files can be inserted back into the original set.
Examples are given below.
The
-linkoffline option takes two arguments
-- the first for the string to be embedded in
the <a href> links, the second telling it where
to find package-list:
o
extdocURL is the absolute or relative URL
of the directory containing the external
javadoc-generated documentation you want to link to.
If relative, the value should be the relative path from the
destination directory (specified with -d) to
the root of the packages being linked to. For more details,
see extdocURL in the -link option.
o
packagelistLoc is the path or URL to the
directory containing the package-list file for
the external documentation. This can be a URL (http: or
file:) or file path, and can be absolute or relative. If
relative, make it relative to the current directory
from where javadoc was run. Do not include the
package-list filename.
You can specify
multiple -linkoffline options in a given
javadoc run. (Prior to 1.2.2, it could be specified only
once.)
Example
using absolute links to the external docs -
Let’s say you want to link to the java.lang,
java.io and other Java 2 Platform packages at
http://java.sun.com/j2se/1.5.0/docs/api, but your
shell does not have web access. You could open the
package-list file in a browser at
http://java.sun.com/j2se/1.5.0/docs/api/package-list
@
http://java.sun.com/j2se/1.5.0/docs/api/package-list,
save it to a local directory, and point to this local copy
with the second argument, packagelistLoc. In this
example, the package list file has been saved to the current
directory "." . The following command
generates documentation for the package com.mypackage
with links to the Java 2 Platform packages. The generated
documentation will contain links to the Object class,
for example, in the class trees. (Other necessary options,
such as -sourcepath, are not shown.)
% javadoc -linkoffline
http://java.sun.com/j2se/1.5.0/docs/api .
com.mypackage
Example
using relative links to the external docs -
It’s not very common to use -linkoffline
with relative paths, for the simple reason that
-link usually suffices. When using
-linkoffline, the package-list
file is generally local, and when using relative links, the
file you are linking to is also generally local. So it is
usually unnecessary to give a different path for the two
arguments to -linkoffline. When the two
arguments are identical, you can use -link. See
the -link relative example.
Manually
Creating a package-list File
- If a package-list file does not yet
exist, but you know what package names your document will
link to, you can create your own copy of this file by hand
and specify its path with packagelistLoc. An example
would be the previous case where the package list for
com.spipackage did not exist when
com.apipackage was first generated. This technique is
useful when you need to generate documentation that links to
new external documentation whose package names you know, but
which is not yet published. This is also a way of creating
package-list files for packages generated with
Javadoc 1.0 or 1.1, where package-list files
were not generated. Likewise, two companies can share their
unpublished package-list files, enabling them
to release their cross-linked documentation
simultaneously.
Linking to
Multiple Documents - You can include
-linkoffline once for each generated document
you want to refer to (each option is shown on a separate
line for clarity):
%
javadoc -linkoffline extdocURL1
packagelistLoc1 \
-linkoffline extdocURL2 packagelistLoc2 \
...
Updating
docs - Another use for -linkoffline
option is useful if your project has dozens or hundreds of
packages, if you have already run javadoc on the entire
tree, and now, in a separate run, you want to quickly make
some small changes and re-run javadoc on just a small
portion of the source tree. This is somewhat of a hack in
that it works properly only if your changes are only to doc
comments and not to declarations. If you were to add, remove
or change any declarations from the source code, then broken
links could show up in the index, package tree, inherited
member lists, use page, and other places.
First, you
create a new destination directory (call it update)
for this new small run. Let’s say the original
destination directory was named html. In the simplest
example, cd to the parent of html. Set the first
argument of -linkoffline to the current
directory "." and set the second argument to the
relative path to html, where it can find
package-list, and pass in only the package
names of the packages you want to update:
% javadoc -d update -linkoffline . html
com.mypackage
When the Javadoc tool is done, copy these generated class
pages in update/com/package (not the overview or
index), over the original files in html/com/package.
-linksource
Creates an HTML version of each
source file (with line numbers) and adds links to them from
the standard HTML documentation. Links are created for
classes, interfaces, constructors, methods and fields whose
declarations are in a source file. Otherwise, links are not
created, such as for default constructors and generated
classes.
This option
exposes all private implementation
details in the included source files, including private
classes, private fields, and the bodies of private
methods, regardless of the
-public,
-package,
-protected and
-private options. Unless you also
use the -private option, not all private
classes or interfaces will necessarily be accessible via
links.
Each link
appears on the name of the identifier in its declaration.
For example, the link to the source code of the
Button class would be on the word "Button":
public class Button
extends Component
implements Accessible
and the link to the source code of the getLabel()
method in the Button class would be on the word
"getLabel":
public String getLabel()
-group groupheading
packagepattern:packagepattern:...
Separates packages on the
overview page into whatever groups you specify, one group
per table. You specify each group with a different
-group option. The groups appear on the page in
the order specified on the command line; packages are
alphabetized within a group. For a given -group
option, the packages matching the list of
packagepattern expressions appear in a table with the
heading groupheading.
o
groupheading can be any text, and can
include white space. This text is placed in the table
heading for the group.
o
packagepattern can be any package name, or
can be the start of any package name followed by an asterisk
(*). The asterisk is a wildcard meaning "match
any characters". This is the only wildcard allowed.
Multiple patterns can be included in a group by separating
them with colons (:).
NOTE: If
using an asterisk in a pattern or pattern list, the pattern
list must be inside quotes, such as
"java.lang*:java.util"
If you do not
supply any -group option, all packages are
placed in one group with the heading "Packages".
If the all groups do not include all documented packages,
any leftover packages appear in a separate group with the
heading "Other Packages".
For example,
the following option separates the four documented packages
into core, extension and other packages. Notice the trailing
"dot" does not appear in "java.lang*"
-- including the dot, such as
"java.lang.*" would omit the java.lang package.
% javadoc -group "Core Packages"
"java.lang*:java.util"
-group "Extension Packages"
"javax.*"
java.lang java.lang.reflect java.util javax.servlet
java.new
This results in the groupings:
Core Packages
java.lang java.lang.reflect
java.util
Extension Packages
javax.servlet
Other Packages
java.new
-nodeprecated
Prevents the generation of any
deprecated API at all in the documentation. This does what
-nodeprecatedlist does, plus it does not generate any
deprecated API throughout the rest of the documentation.
This is useful when writing code and you don’t want to
be distracted by the deprecated code.
-nodeprecatedlist
Prevents the generation of the
file containing the list of deprecated APIs
(deprecated-list.html) and the link in the navigation
bar to that page. (However, javadoc continues to generate
the deprecated API throughout the rest of the document.)
This is useful if your source code contains no deprecated
API, and you want to make the navigation bar cleaner.
-nosince
Omits from the generated docs
the "Since" sections associated with the @since
tags.
-notree
Omits the class/interface
hierarchy pages from the generated docs. These are the pages
you reach using the "Tree" button in the
navigation bar. The hierarchy is produced by default.
-noindex
Omits the index from the
generated docs. The index is produced by default.
-nohelp
Omits the HELP link in the
navigation bars at the top and bottom of each page of
output.
-nonavbar
Prevents the generation of the
navigation bar, header and footer, otherwise found at the
top and bottom of the generated pages. Has no affect on the
"bottom" option. The -nonavbar option
is useful when you are interested only in the content and
have no need for navigation, such as converting the files to
PostScript or PDF for print only.
-helpfile
path/filename
Specifies the path of an
alternate help file path/filename that the HELP link
in the top and bottom navigation bars link to. Without this
option, the Javadoc tool automatically creates a help file
help-doc.html that is hard-coded in the
Javadoc tool. This option enables you to override this
default. The filename can be any name and is not
restricted to help-doc.html -- the
Javadoc tool will adjust the links in the navigation bar
accordingly. For example:
% javadoc -helpfile /home/user/myhelp.html
java.awt
-stylesheetfile
path/filename
Specifies the path of an
alternate HTML stylesheet file. Without this option, the
Javadoc tool automatically creates a stylesheet file
stylesheet.css that is hard-coded in the
Javadoc tool. This option enables you to override this
default. The filename can be any name and is not
restricted to stylesheet.css. For example:
% javadoc -stylesheetfile /home/user/mystylesheet.css
com.mypackage
-serialwarn
Generates compile-time
warnings for missing @serial tags. By default, Javadoc 1.2.2
(and later versions) generates no serial warnings. (This is
a reversal from earlier versions.) Use this option to
display the serial warnings, which helps to properly
document default serializable fields and
writeExternal methods.
-charset name
Specifies the HTML character
set for this document. The name should be a preferred MIME
name as given in the IANA Registry @
http://www.iana.org/assignments/character-sets. For
example:
% javadoc -charset "iso-8859-1"
mypackage
would insert the following line in the head of every
generated page:
<META http-equiv="Content-Type"
content="text/html;
charset=ISO-8859-1">
This META tag is described in the HTML standard @
http://www.w3.org/TR/REC-html40/charset.html#h-5.2.2.
(4197265 and 4137321)
Also see
-encoding and -docencoding.
-docencoding name
Specifies the encoding of the
generated HTML files. The name should be a preferred MIME
name as given in the IANA Registry @
http://www.iana.org/assignments/character-sets. If you
omit this option but use -encoding, then the encoding
of the generated HTML files is determined by
-encoding. Example:
% javadoc -docencoding
"ISO-8859-1" mypackage
Also see -encoding and -charset.
-keywords
Adds HTML meta keyword tags to
the generated file for each class. These tags can help the
page be found by search engines that look for meta tags.
(Most search engines that search the entire Internet do not
look at meta tags, because pages can misuse them; but search
engines offered by companies that confine their search to
their own website can benefit by looking at meta tags.)
The meta tags
include the fully qualified name of the class and the
unqualified names of the fields and methods. Constructors
are not included because they are identical to the class
name. For example, the class String starts with these
keywords:
<META NAME="keywords"
CONTENT="java.lang.String class">
<META NAME="keywords"
CONTENT="CASE_INSENSITIVE_ORDER">
<META NAME="keywords"
CONTENT="length()">
<META NAME="keywords"
CONTENT="charAt()">
-tag tagname:Xaoptcmf:"taghead"
Enables the Javadoc tool to
interpret a simple, one-argument custom block tag
@tagname in doc comments. So the Javadoc tool can
"spell-check" tag names, it is important to
include a -tag option for every custom tag that
is present in the source code, disabling (with X)
those that are not being output in the current run.
The colon
(:) is always the separator. To use a colon in
tagname, see Use of Colon in Tag Name.
The
-tag option outputs the tag’s heading
taghead in bold, followed on the next line by the
text from its single argument, as shown in the example
below. Like any block tag, this argument’s text can
contain inline tags, which are also interpreted. The output
is similar to standard one-argument tags, such as
@return and @author. Omitting taghead
causes tagname to appear as the heading.
Placement of
tags - The Xaoptcmf part of the
argument determines where in the source code the tag is
allowed to be placed, and whether the tag can be disabled
(using X). You can supply either a, to
allow the tag in all places, or any combination of the other
letters: X (disable tag)
a (all)
o (overview)
p (packages)
t (types, that is classes and interfaces)
c (constructors)
m (methods)
f (fields)
Examples of
single tags - An example of a tag option for a tag
that that can be used anywhere in the source code is:
-tag todo:a:"To Do:"
If you wanted @todo to be used only with constructors,
methods and fields, you would use:
-tag todo:cmf:"To Do:"
Notice the last colon (:) above is not a parameter
separator, but is part of the heading text (as shown below).
You would use either tag option for source code that
contains the tag @todo, such as:
@todo The documentation for this method needs work.
Use of Colon in Tag Name - A colon can be used in
a tag name if it is escaped with a backslash. For this doc
comment:
/**
* @ejb:bean
*/
use this tag option:
-tag ejb\\:bean:a:"EJB Bean:"
Spell-checking tag names (Disabling tags) -
Some developers put custom tags in the source code that they
don’t always want to output. In these cases, it is
important to list all tags that are present in the source
code, enabling the ones you want to output and disabling the
ones you don’t want to output. The presence of
X disables the tag, while its absence enables the
tag. This gives the Javadoc tool enough information to know
if a tag it encounters is unknown, probably the results of a
typo or a misspelling. It prints a warning in these
cases.
You can add
X to the placement values already present, so that
when you want to enable the tag, you can simply delete the
X. For example, if @todo is a tag that you want to
suppress on output, you would use:
-tag todo:Xcmf:"To Do:"
or, if you’d rather keep it simple:
-tag todo:X
The syntax
-tag todo:X works even if @todo is
defined by a taglet.
Order of
tags - The order of the -tag (and
-taglet) options determine the order the tags
are output. You can mix the custom tags with the standard
tags to intersperse them. The tag options for standard tags
are placeholders only for determining the order
-- they take only the standard tag’s name.
(Subheadings for standard tags cannot be altered.) This is
illustrated in the following example.
If
-tag is missing, then the position of
-taglet determines its order. If they are both
present, then whichever appears last on the command line
determines its order. (This happens because the tags and
taglets are processed in the order that they appear on the
command line. For example, if -taglet and
-tag both have the name "todo", the
one that appears last on the command line will determine its
order.
Example of a
complete set of tags - This example inserts
"To Do" after "Parameters" and before
"Throws" in the output. By using "X", it
also specifies that @example is a tag that might be
encountered in the source code that should not be output
during this run. Notice that if you use @argfile, you can
put the tags on separate lines in an argument file like this
(no line continuation characters needed):
-tag param
-tag return
-tag todo:a:"To Do:"
-tag throws
-tag see
-tag example:X
When javadoc
parses the doc comments, any tag encountered that is neither
a standard tag nor passed in with -tag or
-taglet is considered unknown, and a warning is
thrown.
The standard
tags are initially stored internally in a list in their
default order. Whenever -tag options are used,
those tags get appended to this list -- standard
tags are moved from their default position. Therefore, if a
-tag option is omitted for a standard tag, it
remains in its default position.
Avoiding
Conflicts - If you want to slice out your own
namespace, you can use a dot-separated naming
convention similar to that used for packages:
com.mycompany.todo. Sun will continue to create
standard tags whose names do not contain dots. Any tag you
create will override the behavior of a tag by the same name
defined by Sun. In other words, if you create a tag or
taglet @todo, it will always have the same behavior
you define, even if Sun later creates a standard tag of the
same name.
Annotations
vs. Javadoc Tags - In general, if the markup you
want to add is intended to affect or produce documentation,
it should probably be a javadoc tag; otherwise, it should be
an annotation. See Comparing Annotations and Javadoc
Tags @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html#annotations
You can also
create more complex block tags, or custom inline tags with
the -taglet option.
-taglet class
Specifies the class file that
starts the taglet used in generating the documentation for
that tag. Use the fully-qualified name for
class. This taglet also defines the number of text
arguments that the custom tag has. The taglet accepts those
arguments, processes them, and generates the output. For
extensive documentation with example taglets, see:
Taglets are
useful for block or inline tags. They can have any number of
arguments and implement custom behavior, such as making text
bold, formatting bullets, writing out the text to a file, or
starting other processes.
Taglets can
only determine where a tag should appear and in what form.
All other decisions are made by the doclet. So a taglet
cannot do things such as remove a class name from the list
of included classes. However, it can execute side effects,
such as printing the tag’s text to a file or
triggering another process.
Use the
-tagletpath option to specify the path to the
taglet. Here is an example that inserts the "To
Do" taglet after "Parameters" and ahead of
"Throws" in the generated pages:
-taglet com.sun.tools.doclets.ToDoTaglet
-tagletpath /home/taglets
-tag return
-tag param
-tag todo
-tag throws
-tag see
Alternatively,
you can use the -taglet option in place of its
-tag option, but that may be harder to read.
-tagletpath tagletpathlist
Specifies the search paths for
finding taglet class files (.class). The
tagletpathlist can contain multiple paths by
separating them with a colon (:). The Javadoc tool
will search in all subdirectories of the specified
paths.
-docfilessubdirs
Enables deep copying of
"doc-files" directories. In other
words, subdirectories and all contents are recursively
copied to the destination. For example, the directory
doc-files/example/images and all its contents
would now be copied. There is also an option to exclude
subdirectories.
-excludedocfilessubdir name1:name2...
Excludes any
"doc-files" subdirectories with the
given names. This prevents the copying of SCCS and other
source-code-control subdirectories.
-noqualifier all
| packagename1:packagename2:...
Omits qualifying package name
from ahead of class names in output. The argument to
-noqualifier is either "all"
(all package qualifiers are omitted) or a
colon-separate list of packages, with wildcards, to be
removed as qualifiers. The package name is removed from
places where class or interface names appear.
The following
example omits all package qualifiers:
-noqualifier all
The following example omits "java.lang" and
"java.io" package qualifiers:
-noqualifier java.lang:java.io
The following example omits package qualifiers starting with
"java", and "com.sun" subpackages (but
not "javax"):
-noqualifier java.*:com.sun.*
Where a package qualifier would appear due to the above
behavior, the name can be suitably shortened --
see How a name is displayed. This rule is in effect whether
or not -noqualifier is used.
-notimestamp
Suppresses the timestamp, which
is hidden in an HTML comment in the generated HTML near the
top of each page. Useful when you want to run javadoc on two
source bases and diff them, as it prevents timestamps from
causing a diff (which would otherwise be a diff on every
page). The timestamp includes the javadoc version number,
and currently looks like this:
<!-- Generated by javadoc (build
1.5.0-internal) on Tue Jun 22 09:57:24 PDT 2004
-->
-nocomment
Suppress the entire comment
body, including the main description and all tags,
generating only declarations. This option enables
re-using source files originally intended for a
different purpose, to produce skeleton HTML documentation at
the early stages of a new project.
automatically inherit comment
The Javadoc tool parses special tags when they are embedded
within a Java doc comment. These doc tags enable you to
autogenerate a complete, well-formatted API from your source
code. The tags start with an "at" sign (@) and are
case-sensitive -- they must be typed with the uppercase and
lowercase letters as shown. A tag must start at the beginning of
a line (after any leading spaces and an optional asterisk) or it
is treated as normal text. By convention, tags with the same name
are grouped together. For example, put all @see tags
together.
Tags come in two types:
o
command line argument files
To shorten or simplify the javadoc command line, you can specify
one or more files that themselves contain arguments to the
javadoc command (except -J options). This enables
you to create javadoc commands of any length on any operating
system.
An argument file can include javac options and source filenames
in any combination. The arguments within a file can be
space-separated or newline-separated. If a filename contains
embedded spaces, put the whole filename in double quotes.
Filenames within an argument file are relative to the current
directory, not the location of the argument file. Wildcards (*)
are not allowed in these lists (such as for specifying
*.java). Use of the ’@’ character to recursively
interpret files is not supported. The -J options are not
supported because they are passed to the launcher, which does not
support argument files.
When executing javadoc, pass in the path and name of each
argument file with the ’@’ leading character. When javadoc
encounters an argument beginning with the character ’@’,
it expands the contents of that file into the argument list.
Example - Single Arg File
You could use a single argument file named "argfile" to
hold all Javadoc arguments:
% javadoc @argfile
This argument file could contain the contents of both files shown
in the next example.
Example - Two Arg Files
You can create two argument files -- one for the Javadoc options
and the other for the package names or source filenames: (Notice
the following lists have no line-continuation characters.)
Create a file named "options" containing:
-d docs-filelist
-use
-splitindex
-windowtitle ’Java 2 Platform v1.3 API Specification’
-doctitle ’Java<sup><font
size="-2">TM</font></sup> 2 Platform 5.0 API
Specification’
-header ’<b>Java 2 Platform </b><br><font
size="-1">5.0</font>’
-bottom ’Copyright 1993-2000 Sun Microsystems, Inc. All Rights
Reserved.’
-group "Core Packages" "java.*"
-overview
/java/pubs/ws/1.5/src/share/classes/overview-core.html
-sourcepath /java/pubs/ws/1.5/src/share/classes
Create a file named "packages" containing:
com.mypackage1
com.mypackage2
com.mypackage3
You would then run javadoc with:
% javadoc @options @packages
Example - Arg Files with Paths
The argument files can have paths, but any filenames inside the
files are relative to the current working directory (not
path1 or path2):
% javadoc @path1/options @path2/packages
Example - Option Arguments
Here’s an example of saving just an argument to a javadoc option
in an argument file. We’ll use the -bottom option, since
it can have a lengthy argument. You could create a file named
"bottom" containing its text argument:
bug or feature</a><br><br>Java is a
trademark or registered trademark of
Sun Microsystems, Inc. in the US and other
countries.<br>Copyright 1993-2000 Sun
Microsystems, Inc. 901 San Antonio Road,<br>Palo Alto,
California, 94303, U.S.A.
All Rights Reserved.</font>’
Then run the Javadoc tool with:
% javadoc -bottom @bottom @packages
Or you could include the -bottom option at the start of
the argument file, and then just run it as:
% javadoc @bottom @packages
case 1 changing to
/home/src/java/applet/Applet.java
This example generates HTML-formatted documentation for the
package java.awt and class Applet. (The Javadoc
tool determines the package name for Applet from the
package declaration, if any, in the Applet.java source
file.)
case 2 run on
java.awt.event
o
case 3 run from any
java.awt.event
o
case 4 run from any
java.awt.event
Result: All cases generate HTML-formatted documentation for the
public and protected classes and interfaces in packages
java.awt and java.awt.event and save the HTML files
in the specified destination directory (/home/html).
Because two or more packages are being generated, the document
has three HTML frames -- for the list of packages, the list of
classes, and the main class pages.
Documenting One or More Classes
The second way to run the Javadoc tool is by passing in one or
more source files (.java). You can run javadoc either of
the following two ways -- by changing directories (with
cd) or by fully-specifying the path to the .java
files. Relative paths are relative to the current directory. The
-sourcepath option is ignored when passing in source
files. You can use command line wildcards, such as asterisk (*),
to specify groups of classes.
o
documentation comments
The original "Documentation Comment Specification" can be found
under related documentation.
Commenting the Source Code
You can include documentation comments ("doc comments") in
the source code, ahead of declarations for any class, interface,
method, constructor, or field. You can also create doc comments
for each package and another one for the overview, though their
syntax is slightly different. Doc comments are also known
informally as "Javadoc comments" (but this term violates its
trademark usage). A doc comment consists of the characters
between the characters /** that begin the comment and the
characters */ that end it. Leading asterisks are allowed
on each line and are described further below. The text in a
comment can continue onto multiple lines.
/**
* This is the typical format of a simple documentation
comment
* that spans two lines.
*/
To save space you can put a comment on one line:
/** This comment takes up only one line. */
Placement of comments - Documentation comments are
recognized only when placed immediately before class, interface,
constructor, method, or field declarations -- see the class
example, method example, and field example. Documentation
comments placed in the body of a method are ignored. Only one
documentation comment per declaration statement is recognized by
the Javadoc tool.
A common mistake is to put an import statement between the
class comment and the class declaration. Avoid this, as the
Javadoc tool will ignore the class comment.
/**
* This is the class comment for the class Whatever.
*/
import com.sun; // MISTAKE - Important not to put import
statement here
public class Whatever {
}
A doc comment is composed of a main
description followed by a tag
section - The main description begins after the
starting delimiter /** and continues until the tag
section. The tag section starts with the first block tag,
which is defined by the first @ character that begins a
line (ignoring leading asterisks, white space, and leading
separator /**). It is possible to have a comment with only
a tag section and no main description. The main description
cannot continue after the tag section begins. The argument to a
tag can span multiple lines. There can be any number of tags --
some types of tags can be repeated while others cannot. For
example, this @see starts the tag section:
/**
* This sentence would hold the main description for this doc
comment.
* @see java.lang.Object
*/
Block tags and in-line tags - A tag is a special
keyword within a doc comment that the Javadoc tool can process.
There are two kinds of tags: block tags, which appear as
@tag (also known as "standalone tags"), and in-line tags,
which appear within curly braces, as {@tag}. To be
interpreted, a block tag must appear at the beginning of a line,
ignoring leading asterisks, white space, and separator
(/**). This means you can use the @ character
elsewhere in the text and it will not be interpreted as the start
of a tag. If you want to start a line with the @ character
and not have it be interpreted, use the HTML entity
@. Each block tag has associated text, which
includes any text following the tag up to, but not including,
either the next tag, or the end of the doc comment. This
associated text can span multiple lines. An in-line tag is
allowed and interpreted anywhere that text is allowed. The
following example contains the block tag @deprecated and
in-line tag {@link}.
/**
* @deprecated As of JDK 1.1, replaced by {@link
#setBounds(int,int,int,int)}
*/
Comments are written in HTML - The text must be written in
HTML, in that they should use HTML entities and can use HTML
tags. You can use whichever version of HTML your browser
supports; we have written the standard doclet to generate HTML
3.2-compliant code elsewhere (outside of the documentation
comments) with the inclusion of cascading style sheets and
frames. (We preface each generated file with "HTML 4.0" because
of the frame sets.)
For example, entities for the less-than (<) and
greater-than (>) symbols should be written <
and >. Likewise, the ampersand (&) should be
written &. The bold HTML tag <b> is shown in
the following example.
Here is a doc comment:
/**
* This is a <b>doc</b> comment.
* @see java.lang.Object
*/
Leading asterisks - When javadoc parses a doc comment,
leading asterisk (*) characters on each line are
discarded; blanks and tabs preceding the initial asterisk
(*) characters are also discarded. Starting with 1.4, if
you omit the leading asterisk on a line, the leading white space
is no longer removed. This enables you to paste code examples
directly into a doc comment inside a <PRE> tag, and
its indentation will be honored. Spaces are generally interpreted
by browsers more uniformly than tabs. Indentation is relative to
the left margin (rather than the separator /** or
<PRE> tag).
First sentence - The first sentence of each doc comment
should be a summary sentence, containing a concise but complete
description of the declared entity. This sentence ends at the
first period that is followed by a blank, tab, or line
terminator, or at the first block tag. The Javadoc tool copies
this first sentence to the member summary at the top of the HTML
page.
Declaration with multiple fields - Java allows declaring
multiple fields in a single statement, but this statement can
have only one documentation comment, which is copied for all
fields. Therefore if you want individual documentation comments
for each field, you must declare each field in a separate
statement. For example, the following documentation comment
doesn’t make sense written as a single declaration and would be
better handled as two declarations:
/**
* The horizontal and vertical distances of point (x,y)
*/
public int x, y; // Avoid this
The Javadoc tool generates the following documentation from the
above code:
public int x
The horizontal and vertical distances of point (x,y)
public int y
The horizontal and vertical distances of point (x,y)
Use header tags carefully - When writing documentation
comments for members, it’s best not to use HTML heading tags such
as <H1> and <H2>, because the Javadoc tool creates an
entire structured document and these structural tags might
interfere with the formatting of the generated document. However,
it is fine to use these headings in class and package comments to
provide your own structure.
Automatic Copying of Method Comments
The Javadoc tool has the ability to copy or "inherit" method
comments in classes and interfaces under the following two
circumstances. Constructors, fields and nested classes do not
inherit doc comments.
o
Automatically inherit comment to fill in missing text -
When a main description, or @return, @param or
@throws tag is missing from a method comment, the Javadoc
tool copies the corresponding main description or tag comment
from the method it overrides or implements (if any), according to
the algorithm below.
More specifically, when a @param tag for a particular
parameter is missing, then the comment for that parameter is
copied from the method further up the inheritance hierarchy. When
a @throws tag for a particular exception is missing, the
@throws tag is copied only if that exception is
declared.
This behavior contrasts with version 1.3 and earlier, where the
presence of any main description or tag would prevent all
comments from being inherited.
o
Explicitly inherit comment with {@inheritDoc} tag - Insert
the inline tag {@inheritDoc} in a method main description
or @return, @param or @throws tag comment --
the corresponding inherited main description or tag comment is
copied into that spot.
The source file for the inherited method need only be on the path
specified by -sourcepath for the doc comment to actually be
available to copy. Neither the class nor its package needs to be
passed in on the command line. This contrasts with 1.3.x and
earlier releases, where the class had to be a documented class
Inherit from classes and interfaces - Inheriting of
comments occurs in all three possible cases of inheritance from
classes and interfaces:
o
When a method in a class overrides a method in a superclass
o
When a method in an interface overrides a method in a
superinterface
o
When a method in a class implements a method in an interface
In the first two cases, for method overrides, the Javadoc tool
generates a subheading "Overrides" in the documentation for the
overriding method, with a link to the method it is overriding,
whether or not the comment is inherited.
In the third case, when a method in a given class implements a
method in an interface, the Javadoc tool generates a subheading
"Specified by" in the documentation for the overriding method,
with a link to the method it is implementing. This happens
whether or not the comment is inherited.
Algorithm for Inheriting Method Comments - If a method
does not have a doc comment, or has an {@inheritDoc} tag, the
Javadoc tool searches for an applicable comment using the
following algorithm, which is designed to find the most specific
applicable doc comment, giving preference to interfaces over
superclasses:
1.
Look in each directly implemented (or extended) interface in the
order they appear following the word implements (or extends) in
the method declaration. Use the first doc comment found for this
method.
2.
If step 1 failed to find a doc comment, recursively apply this
entire algorithm to each directly implemented (or extended)
interface, in the same order they were examined in step 1.
3.
If step 2 failed to find a doc comment and this is a class other
than Object (not an interface):
a.
If the superclass has a doc comment for this method, use it.
b.
If step 3a failed to find a doc comment, recursively apply this
entire algorithm to the superclass.
environment
CLASSPATH
Environment variable that provides the path which javadoc uses to
find user class files. This environment variable is overridden by
the -classpath option. Separate directories with a colon,
for example:
generated files
By default, javadoc uses a standard doclet that generates
HTML-formatted documentation. This doclet generates the following
kinds of files (where each HTML "page" corresponds to a separate
file). Note that javadoc generates files with two types of names:
those named after classes/interfaces, and those that are not
(such as package-summary.html). Files in the latter group
contain hyphens to prevent filename conflicts with those in the
former group.
Basic Content Pages
o
One class or interface page (classname.html) for
each class or interface it is documenting.
o
One package page (package-summary.html) for each
package it is documenting. The Javadoc tool will include any HTML
text provided in a file named package.html or
package-info.java in the package directory of the source
tree.
o
One overview page (overview-summary.html) for the
entire set of packages. This is the front page of the generated
document. The Javadoc tool will include any HTML text provided in
a file specified with the -overview option. Note that this
file is created only if you pass into javadoc two or more package
names. For further explanation, see HTML Frames.)
Cross-Reference Pages
o
One class hierarchy page for the entire set of packages
(overview-tree.html). To view this, click on "Overview" in
the navigation bar, then click on "Tree".
o
One class hierarchy page for each package
(package-tree.html) To view this, go to a particular
package, class or interface page; click "Tree" to display the
hierarchy for that package.
o
One "use" page for each package (package-use.html)
and a separate one for each class and interface
(class-use/classname.html). This page describes what
packages, classes, methods, constructors and fields use any part
of the given class, interface or package. Given a class or
interface A, its "use" page includes subclasses of A, fields
declared as A, methods that return A, and methods and
constructors with parameters of type A. You can access this page
by first going to the package, class or interface, then clicking
on the "Use" link in the navigation bar.
o
A deprecated API page (deprecated-list.html)
listing all deprecated names. (A deprecated name is not
recommended for use, generally due to improvements, and a
replacement name is usually given. Deprecated APIs may be removed
in future implementations.)
o
A constant field values page (constant-values.html)
for the values of static fields.
o
A serialized form page (serialized-form.html) for
information about serializable and externalizable classes. Each
such class has a description of its serialization fields and
methods. This information is of interest to re-implementors, not
to developers using the API. While there is no link in the
navigation bar, you can get to this information by going to any
serialized class and clicking "Serialized Form" in the "See also"
section of the class comment. The standard doclet automatically
generates a serialized form page: any class (public or
non-public) that implements Serializable is included, along with
readObject and writeObject methods, the fields that
are serialized, and the doc comments from the @serial,
@serialField, and @serialData tags. Public
serializable classes can be excluded by marking them (or their
package) with @serial exclude, and package-private
serializable classes can be included by marking them (or their
package) with @serial include. As of 1.4, you can generate
the complete serialized form for public and private classes by
running javadoc without specifying the -private
option.
o
An index (index-*.html) of all class, interface,
constructor, field and method names, alphabetically arranged.
This is internationalized for Unicode and can be generated as a
single file or as a separate file for each starting character
(such as A-Z for English).
Support Files
o
A help page (help-doc.html) that describes the
navigation bar and the above pages. You can provide your own
custom help file to override the default using -helpfile.
o
One index.html file which creates the HTML frames for
display. This is the file you load to display the front page with
frames. This file itself contains no text content.
o
Several frame files (*-frame.html) containing lists
of packages, classes and interfaces, used when HTML frames are
being displayed.
o
A package list file (package-list), used by the
-link and -linkoffline options. This is a text
file, not HTML, and is not reachable through any links.
o
A style sheet file (stylesheet.css) that controls a
limited amount of color, font family, font size, font style and
positioning on the generated pages.
o
A doc-files directory that holds any image, example,
source code or other files that you want copied to the
destination directory. These files are not processed by the
Javadoc tool in any manner -- that is, any javadoc tags in them
will be ignored. This directory is not generated unless it exists
in the source tree.
HTML Frames
The Javadoc tool will generate either two or three HTML frames,
as shown in the figure below. It creates the minimum necessary
number of frames by omitting the list of packages if there is
only one package (or no packages). That is, when you pass a
single package name or source files (*.java) belonging to a
single package as arguments into the javadoc command, it will
create only one frame (C) in the left-hand column -- the list of
classes. When you pass into javadoc two or more package names, it
creates a third frame (P) listing all packages, as well as an
overview page (Detail). This overview page has the filename
overview-summary.html. Thus, this file is created only if
you pass in two or more package names. You can bypass frames by
clicking on the "No Frames" link or entering at
overview-summary.html.
If you are unfamiliar with HTML frames, you should be aware that
frames can have focus for printing and scrolling. To give
a frame focus, click on it. Then on many browsers the arrow keys
and page keys will scroll that frame, and the print menu command
will print it.
------------ ------------
|C| Detail | |P| Detail |
| | | | | |
| | | |-| |
| | | |C| |
| | | | | |
| | | | | |
------------ ------------
javadoc *.java javadoc java.lang java.awt
Load one of the following two files as the starting page
depending on whether you want HTML frames or not:
o
index.html (for frames)
o
overview-summary.html (for no frames)
Generated File Structure
The generated class and interface files are organized in the same
directory hierarchy that Java source files and class files are
organized. This structure is one directory per subpackage.
For example, the document generated for the class
java.applet.Applet class would be located at
java/applet/Applet.html. The file structure for the
java.applet package follows, given that the destination directory
is named apidocs. All files that contain the word "frame"
appear in the upper-left or lower-left frames, as noted. All
other HTML files appear in the right-hand frame.
NOTE - Directories are shown in bold. The asterisks
(*) indicate the files and directories that are
omitted when the arguments to javadoc are source filenames
(*.java) rather than package names. Also when arguments are
source filenames, package-list is created but is empty.
The doc-files directory will not be created in the destination
unless it exists in the source tree.
apidocs Top directory
index.html Initial page that sets up HTML frames
* overview-summary.html Lists all packages with first sentence
summaries
overview-tree.html Lists class hierarchy for all packages
deprecated-list.html Lists deprecated API for all packages
constant-values.html Lists values of static fields for all
packages
serialized-form.html Lists serialized form for all packages
* overview-frame.html Lists all packages, used in upper-left
frame
allclasses-frame.html Lists all classes for all packages, used in
lower-left frame
help-doc.html Lists user help for how these pages are
organized
index-all.html Default index created without -splitindex option
index-files Directory created with -splitindex option
index-<number>.html Index files created with -splitindex
option
package-list Lists package names, used only for resolving
external refs
stylesheet.css HTML style sheet for defining fonts, colors and
positions
java Package directory
applet Subpackage directory
Applet.html Page for Applet class
AppletContext.html Page for AppletContext interface
AppletStub.html Page for AppletStub interface
AudioClip.html Page for AudioClip interface
* package-summary.html Lists classes with first sentence
summaries for this package
* package-frame.html Lists classes in this package, used in lower
left-hand frame
* package-tree.html Lists class hierarchy for this package
package-use Lists where this package is used
doc-files Directory holding image and example files
class-use Directory holding pages API is used
Applet.html Page for uses of Applet class
AppletContext.html Page for uses of AppletContext interface
AppletStub.html Page for uses of AppletStub interface
AudioClip.html Page for uses of AudioClip interface
src-html Source code directory
java Package directory
applet Subpackage directory
Applet.html Page for Applet source code
AppletContext.html Page for AppletContext source code
AppletStub.html Page for AppletStub source code
AudioClip.html Page for AudioClip source code
a name="generatedapideclarations"/> Generated API
Declarations
The Javadoc tool generates a declaration at the start of each
class, interface, field, constructor, and method description for
that API item. For example, the declaration for the
Boolean class is:
public final class Boolean
extends Object
implements Serializable
and the declaration for the Boolean.valueOfmethod is:
public static Boolean valueOf(String s)
The Javadoc tool can include the modifiers public,
protected, private, abstract, final,
static, transient, and volatile, but not
synchronized or native. These last two modifiers
are considered implementation detail and not part of the API
specification.
Rather than relying on the keyword synchronized, APIs
should document their concurrency semantics in the comment’s main
description, as in "a single Enumeration cannot be used by
multiple threads concurrently". The document should not describe
how to achieve these semantics. As another example, while
Hashtable should be thread-safe, there’s no reason to
specify that we achieve this by synchronizing all of its exported
methods. We should reserve the right to synchronize internally at
the bucket level, thus offering higher concurrency.
javadoc tags
The Javadoc tool parses special tags when they are embedded
within a Java doc comment. These doc tags enable you to
autogenerate a complete, well-formatted API from your source
code. The tags start with an "at" sign (@) and are
case-sensitive -- they must be typed with the uppercase and
lowercase letters as shown. A tag must start at the beginning of
a line (after any leading spaces and an optional asterisk) or it
is treated as normal text. By convention, tags with the same name
are grouped together. For example, put all @see tags
together.
Tags come in two types:
o
Block tags - Can be placed only in the tag section that
follows the main description. Block tags are of the form:
@tag.
o
Inline tags - Can be placed anywhere in the main
description or in the comments for block tags. Inline tags are
denoted by curly braces: {@tag}.
For information about tags we might introduce in future releases,
see Proposed Tags @
http://java.sun.com/j2se/javadoc/proposed-tags.html.
The current tags are:
For custom tags, see the -tag option.
@author name-text
Adds an "Author" entry with the specified name-text to the
generated docs when the -author option is used. A doc comment may
contain multiple @author tags. You can specify one name
per @author tag or multiple names per tag. In the former
case, the Javadoc tool inserts a comma (,) and space
between names. In the latter case, the entire text is simply
copied to the generated document without being parsed. Therefore,
you can use multiple names per line if you want a localized name
separator other than comma.
For more details, see Where Tags Can Be Used and writing
@author tags @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html#@author.
@deprecated deprecated-text
Note: Starting with JDK 5.0, you can deprecate a program element
using the @Deprecated annotation.
Adds a comment indicating that this API should no longer be used
(even though it may continue to work). The Javadoc tool moves the
deprecated-text ahead of the main description, placing it
in italics and preceding it with a bold warning: "Deprecated".
This tag is valid in all doc comments: overview, package, class,
interface, constructor, method and field.
The first sentence of deprecated-text should at least tell
the user when the API was deprecated and what to use as a
replacement. The Javadoc tool copies just the first sentence to
the summary section and index. Subsequent sentences can also
explain why it has been deprecated. You should include a
{@link} tag (for Javadoc 1.2 or later) that points to the
replacement API:
For more details, see writing @deprecated tags @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html#@deprecated.
o
For Javadoc 1.2 and later, use a {@link} tag. This creates
the link in-line, where you want it. For example:
/**
* @deprecated As of JDK 1.1, replaced by {@link
#setBounds(int,int,int,int)}
*/
o
For Javadoc 1.1, the standard format is to create a @see
tag (which cannot be in-line) for each @deprecated tag.
For more about deprecation, see The @deprecated tag.
{@code text}
Equivalent to <code>{@literal}</code>.
Displays text in code font without interpreting the
text as HTML markup or nested javadoc tags. This enables you to
use regular angle brackets (< and >) instead
of the HTML entities (< and >) in doc
comments, such as in parameter types (<Object>),
inequalities (3 < 4), or arrows (<-). For
example, the doc comment text:
{@code A<B>C}
displays in the generated HTML page unchanged, as:
A<B>C
The noteworthy point is that the <B> is not
interpreted as bold and is in code font.
If you want the same functionality without the code font, use
{@literal}.
{@docRoot}
Represents the relative path to the generated document’s
(destination) root directory from any generated page. It is
useful when you want to include a file, such as a copyright page
or company logo, that you want to reference from all generated
pages. Linking to the copyright page from the bottom of each page
is common.
This {@docRoot} tag can be used both on the command line
and in a doc comment: This tag is valid in all doc comments:
overview, package, class, interface, constructor, method and
field, including the text portion of any tag (such as @return,
@param and @deprecated).
1.
On the command line, where the header/footer/bottom are defined:
javadoc -bottom ’<a
href="{@docRoot}/copyright.html">Copyright</a>’
NOTE - When using {@docRoot} this way in a make file, some
makefile programs require special escaping for the brace {}
characters. For example, the Inprise MAKE version 5.2 running on
Windows requires double braces: {{@docRoot}}. It also
requires double (rather than single) quotes to enclose arguments
to options such as -bottom (with the quotes around the
href argument omitted).
2.
In a doc comment:
/**
* See the <a
href="{@docRoot}/copyright.html">Copyright</a>.
*/
The reason this tag is needed is because the generated docs are
in hierarchical directories, as deep as the number of
subpackages. This expression:
<a href="{@docRoot}/copyright.html">
would resolve to:
<a href="../../copyright.html"> for
java/lang/Object.java
and
<a href="../../../copyright.html"> for
java/lang/ref/Reference.java
@exception class-name description
The @exception tag is a synonym for @throws.
{@inheritDoc}
Inherits (copies) documentation from the "nearest" inheritable
class or implementable interface into the current doc comment at
this tag’s location. This allows you to write more general
comments higher up the inheritance tree, and to write around the
copied text.
This tag is valid only in these places in a doc comment:
o
In the main description block of a method. In this case, the main
description is copied from a class or interface up the hierarchy.
o
In the text arguments of the @return, @param and @throws tags of
a method. In this case, the tag text is copied from the
corresponding tag up the hierarchy.
See Automatic Copying of Method Comments for a more precise
description of how comments are found in the inheritance
hierarchy. Note that if this tag is missing, the comment is or is
not automatically inherited according to rules described in that
section.
{@link package.class#member label}
Inserts an in-line link with visible text label that
points to the documentation for the specified package, class or
member name of a referenced class. This tag is valid in all doc
comments: overview, package, class, interface, constructor,
method and field, including the text portion of any tag (such as
@return, @param and @deprecated).
This tag is very simliar to @see -- both require the same
references and accept exactly the same syntax for
package.class#member and label. The main difference
is that {@link} generates an in-line link rather than
placing the link in the "See Also" section. Also, the
{@link} tag begins and ends with curly braces to separate
it from the rest of the in-line text. If you need to use "}"
inside the label, use the HTML entity notation }
There is no limit to the number of {@link} tags allowed in
a sentence. You can use this tag in the main description part of
any documentation comment or in the text portion of any tag (such
as @deprecated, @return or @param).
For example, here is a comment that refers to the
getComponentAt(int, int) method:
Use the {@link #getComponentAt(int, int) getComponentAt}
method.
From this, the standard doclet would generate the following HTML
(assuming it refers to another class in the same package):
Use the <a href="Component.html#getComponentAt(int,
int)">getComponentAt</a> method.
Which appears on the web page as:
Use the getComponentAt method.
You can extend {@link} to link to classes not being
documented by using the -link option.
For more details, see writing {@link} tags @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html#{@link}.
{@linkplain package.class#member label}
Identical to {@link}, except the link’s label is displayed
in plain text than code font. Useful when the label is plain
text. Example:
Refer to {@linkplain add() the overridden method}.
This would display as:
Refer to the overridden method.
{@literal text}
Displays text without interpreting the text as HTML markup
or nested javadoc tags. This enables you to use regular angle
brackets (< and >) instead of the HTML
entities (< and >) in doc comments, such as
in parameter types (<Object>), inequalities (3
< 4), or arrows (<-). For example, the doc
comment text:
{@literal A<B>C}
displays unchanged in the generated HTML page in your browser,
as:
A<B>C The noteworthy point is that the <B> is
not interpreted as bold (and it is not in code font).
If you want the same functionality but with the text in code
font, use {@code}.
@param parameter-name description
Adds a parameter with the specified parameter-name
followed by the specified description to the "Parameters"
section. When writing the doc comment, you may continue the
description onto multiple lines. This tag is valid only in
a doc comment for a method, constructor or class.
The parameter-name can be the name of a parameter in a
method or constructor, or the name of a type parameter of a
class, method or constructor. Use angle brackets around this
parameter name to specify the use of a type parameter.
Example of a type parameter of a class:
/**
* @param <E> Type of element stored in a list
*/
public interface List<E> extends Collection<E> {
}
Example of a type parameter of a method:
/**
* @param string the string to be converted
* @param type the type to convert the string to
* @param <T> the type of the element
* @param <V> the value of the element
*/
<T, V extends T> V convert(String string, Class<T>
type) {
}
For more details, see writing @param tags @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html#@param.
@return description
Adds a "Returns" section with the description text. This
text should describe the return type and permissible range of
values. This tag is valid only in a doc comment for a method.
For more details, see writing @return tags @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html#@return.
@see reference
Adds a "See Also" heading with a link or text entry that points
to reference. A doc comment may contain any number of
@see tags, which are all grouped under the same heading.
The @see tag has three variations; the third form below is
the most common. This tag is valid in any doc comment: overview,
package, class, interface, constructor, method or field. For
inserting an in-line link within a sentence to a package, class
or member, see {@link}.
@see "string"
Adds a text entry for string. No link is generated. The
string is a book or other reference to information not
available by URL. The Javadoc tool distinguishes this from the
previous cases by looking for a double-quote (") as the
first character. For example:
@see "The Java Programming Language"
This generates text such as:
See Also:
"The Java Programming Language"
@see <a href="URL#value">label</a>
Adds a link as defined by URL#value. The
URL#value is a relative or absolute URL. The
Javadoc tool distinguishes this from other cases by looking for a
less-than symbol (<) as the first character. For
example:
@see <a href="spec.html#section">Java
Spec</a>
This generates a link such as:
See Also:
Java Spec
@see package.class#member label
Adds a link, with visible text label, that points to the
documentation for the specified name in the Java Language that is
referenced. The label is optional; if omitted, the name
appears instead as the visible text, suitably shortened -- see
How a name is displayed. Use -noqualifier to globally remove the
package name from this visible text. Use the label when you want
the visible text to be different from the auto-generated visible
text.
Only in version 1.2, just the name but not the label would
automatically appear in <code> HTML tags, Starting with
1.2.2, the <code> is always included around the visible
text, whether or not a label is used.
o
package.class#member is any valid program element
name that is referenced -- a package, class, interface,
constructor, method or field name -- except that the character
ahead of the member name should be a hash character (#).
The class represents any top-level or nested class or
interface. The member represents any constructor, method
or field (not a nested class or interface). If this name is in
the documented classes, the Javadoc tool will automatically
create a link to it. To create links to external referenced
classes, use the -link option. Use either of the other two
@see forms for referring to documentation of a name that
does not belong to a referenced class. This argument is described
at greater length below under Specifying a Name.
o
label is optional text that is visible as the
link’s label. The label can contain whitespace. If
label is omitted, then package.class.member will
appear, suitably shortened relative to the current class and
package -- see How a name is displayed.
o
A space is the delimiter between package.class#member and
label. A space inside parentheses does not indicate the
start of a label, so spaces may be used between parameters in a
method.
Example - In this example, an @see tag (in the
Character class) refers to the equals method in the
String class. The tag includes both arguments: the name
"String#equals(Object)" and the label "equals".
/**
* @see String#equals(Object) equals
*/
The standard doclet produces HTML something like this:
<dl>
<dt><b>See Also:</b>
<dd><a
href="../../java/lang/String#equals(java.lang.Object)"><code>equals<code></a>
</dl>
Which looks something like this in a browser, where the label is
the visible link text:
See Also:
equals
Specifying a name - This package.class#member name
can be either fully-qualified, such as
java.lang.String#toUpperCase() or not, such as
String#toUpperCase() or #toUpperCase(). If less
than fully-qualified, the Javadoc tool uses the normal Java
compiler search order to find it, further described below in
Search order for @see. The name can contain whitespace within
parentheses, such as between method arguments.
Of course the advantage of providing shorter,
"partially-qualified" names is that they are shorter to type and
there is less clutter in the source code. The following table
shows the different forms of the name, where Class can be
a class or interface, Type can be a class, interface,
array, or primitive, and method can be a method or
constructor.
The following notes apply to the above table:
o
The first set of forms (with no class or package) will cause the
Javadoc tool to search only through the current class’s
hierarchy. It will find a member of the current class or
interface, one of its superclasses or superinterfaces, or one of
its enclosing classes or interfaces (search steps 1-3). It will
not search the rest of the current package or other packages
(search steps 4-5).
o
If any method or constructor is entered as a name with no
parentheses, such as getValue, and if there is no field
with the same name, the Javadoc tool will correctly create a link
to it, but will print a warning message reminding you to add the
parentheses and arguments. If this method is overloaded, the
Javadoc tool will link to the first method its search encounters,
which is unspecified.
o
Nested classes must be specified as outer.inner, not
simply inner, for all forms.
o
As stated, the hash character (#), rather than a dot
(.) separates a member from its class. This enables the
Javadoc tool to resolve ambiguities, since the dot also separates
classes, nested classes, packages, and subpackages. However, the
Javadoc tool is generally lenient and will properly parse a dot
if you know there is no ambiguity, though it will print a
warning.
Search order for @see - the Javadoc tool will process a
@see tag that appears in a source file (.java), package
file (package.html or package-info.java) or overview file
(overview.html). In the latter two files, you must fully-qualify
the name you supply with @see. In a source file, you can
specify a name that is fully-qualified or partially-qualified.
When the Javadoc tool encounters a @see tag in a
.java file that is not fully qualified, it searches
for the specified name in the same order as the Java compiler
would (except the Javadoc tool will not detect certain namespace
ambiguities, since it assumes the source code is free of these
errors). This search order is formally defined in Chapter 6,
"Names" of the Java Language Specification, Second
Edition. The Javadoc tool searches for that name through all
related and imported classes and packages. In particular, it
searches in this order:
1.
the current class or interface
2.
any enclosing classes and interfaces, searching closest first
3.
any superclasses and superinterfaces, searching closest first
4.
the current package
5.
any imported packages, classes and interfaces, searching in the
order of the import statement
The Javadoc tool continues to search recursively through steps
1-3 for each class it encounters until it finds a match. That is,
after it searches through the current class and its enclosing
class E, it will search through E’s superclasses before E’s
enclosing classes. In steps 4 and 5, the Javadoc tool does not
search classes or interfaces within a package in any specified
order (that order depends on the particular compiler). In step 5,
the Javadoc tool looks in java.lang, since that is automatically
imported by all programs.
The Javadoc tool does not necessarily look in subclasses, nor
will it look in other packages even if their documentation is
being generated in the same run. For example, if the @see
tag is in the java.awt.event.KeyEvent class and refers to
a name in the java.awt package, javadoc does not look in
that package unless that class imports it.
How a name is displayed - If label is omitted, then
package.class.member appears. In general, it is suitably
shortened relative to the current class and package. By
"shortened", we mean the Javadoc tool displays only the minimum
name necessary. For example, if the String.toUpperCase()
method contains references to a member of the same class and to a
member of a different class, the class name is displayed only in
the latter case, as shown in the following table.
Use -noqualifier to globally remove the package names.
Examples of @see
The comment to the right shows how the name would be displayed if
the @see tag is in a class in another package, such as
java.applet.Applet.
See also:
@see java.lang.String // String
@see java.lang.String The String class // The String class
@see String // String
@see String#equals(Object) // String.equals(Object)
@see String#equals // String.equals(java.lang.Object)
@see java.lang.Object#wait(long) //
java.lang.Object.wait(long)
@see Character#MAX_RADIX // Character.MAX_RADIX
@see <a href="spec.html">Java Spec</a> // Java
Spec
@see "The Java Programming Language" // "The Java Programming
Language"
You can extend @see to link to classes not being
documented by using the -link option.
For more details, see writing @see tags @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html#@see.
@serial field-description | include | exclude
Used in the doc comment for a default serializable field.
An optional field-description should explain the meaning
of the field and list the acceptable values. If needed, the
description can span multiple lines. The standard doclet adds
this information to the serialized form page.
If a serializable field was added to a class some time after the
class was made serializable, a statement should be added to its
main description to identify at which version it was added.
The include and exclude arguments identify whether
a class or package should be included or excluded from the
serialized form page. They work as follows:
o
A public or protected class that implements Serializable
is included unless that class (or its package) is marked
@serial exclude.
o
A private or package-private class that implements
Serializable is excluded unless that class (or its
package) is marked @serial include.
Examples: The javax.swing package is marked @serial
exclude (in package.html or package-info.java).
The public class java.security.BasicPermission is marked
@serial exclude. The package-private class
java.util.PropertyPermissionCollection is marked
@serial include.
The tag @serial at a class level overrides @serial at a package
level.
For more information about how to use these tags, along with an
example, see "Documenting Serializable Fields and Data for a
Class," Section 1.6 of the Java Object Serialization
Specification. Also see the Serialization FAQ @
http://java.sun.com/products/jdk/serialization/faq/#javadoc_warn_missing,
which covers common questions, such as "Why do I see javadoc
warnings stating that I am missing @serial tags for private
fields if I am not running javadoc with the -private switch?".
Also see Sun’s criteria @
http://java.sun.com/j2se/javadoc/writingapispecs/serialized-criteria.html
for including classes in the serialized form specification.
@serialField field-name field-type
field-description
Documents an ObjectStreamField component of a
Serializable class’s serialPersistentFields member.
One @serialField tag should be used for each
ObjectStreamField component.
@serialData data-description
The data-description documents the types and order of data
in the serialized form. Specifically, this data includes the
optional data written by the writeObject method and all
data (including base classes) written by the
Externalizable.writeExternal method.
The @serialData tag can be used in the doc comment for the
writeObject, readObject, writeExternal,
readExternal, writeReplace, and readResolve
methods.
@since since-text
Adds a "Since" heading with the specified since-text to
the generated documentation. The text has no special internal
structure. This tag is valid in any doc comment: overview,
package, class, interface, constructor, method or field. This tag
means that this change or feature has existed since the software
release specified by the since-text. For example:
@since 1.5
For source code in the Java platform, this tag indicates the
version of the Java platform API specification (not necessarily
when it was added to the reference implementation). Multiple
@since tags are allowed and are treated like multiple @author
tags. You could use multiple tags if the prgram element is used
by more than one API.
@throws class-name description
The @throws and @exception tags are synonyms. Adds
a "Throws" subheading to the generated documentation, with the
class-name and description text. The
class-name is the name of the exception that may be thrown
by the method. This tag is valid only in the doc comment for a
method or constructor. If this class is not fully-specified, the
Javadoc tool uses the search order to look up this class.
Multiple @throws tags can be used in a given doc comment
for the same or different exceptions.
To ensure that all checked exceptions are documented, if a
@throws tag does not exist for an exception in the throws
clause, the Javadoc tool automatically adds that exception to the
HTML output (with no description) as if it were documented with
@throws tag.
The @throws documentation is copied from an overridden
method to a subclass only when the exception is explicitly
declared in the overridden method. The same is true for copying
from an interface method to an implementing method. You can use
{@inheritDoc} to force @throws to inherit documentation.
For more details, see writing @throws tags @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html#@exception.
{@value package.class#field}
When {@value} is used (without any argument) in the doc
comment of a static field, it displays the value of that
constant:
/**
* The value of this constant is {@value}.
*/
public static final String SCRIPT_START =
"<script>"
When used with argument package.class#field in any doc
comment, it displays the value of the specified constant:
/**
* Evaluates the script starting with {@value #SCRIPT_START}.
*/
public String evalScript(String script) {
}
The argument package.class#field takes a form identical to
that of the @see argument, except that the member must be a
static field.
These values of these constants are also displayed on the
Constant Field Values page.
@version version-text
Adds a "Version" subheading with the specified
version-text to the generated docs when the -version
option is used. This tag is intended to hold the current version
number of the software that this code is part of (as opposed to
@since, which holds the version number where this code was
introduced). The version-text has no special internal
structure. To see where the version tag can be used, see Where
Tags Can Be Used.
A doc comment may contain multiple @version tags. If it
makes sense, you can specify one version number per
@version tag or multiple version numbers per tag. In the
former case, the Javadoc tool inserts a comma (,) and
space between names. In the latter case, the entire text is
simply copied to the generated document without being parsed.
Therefore, you can use multiple names per line if you want a
localized name separator other than comma.
For more details, see writing @version tags @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html#@version.
Where Tags Can Be Used
The following sections describe where the tags can be used. Note
that these tags can be used in all doc comments: @see,
@since, @deprecated, {@link},
{@linkplain}, and {@docroot}.
Overview Documentation Tags
Overview tags are tags that can appear in the documentation
comment for the overview page (which resides in the source file
typically named overview.html). Like in any other
documentation comments, these tags must appear after the main
description.
NOTE - The {@link} tag has a bug in overview
documents in version 1.2 -- the text appears properly but has no
link. The {@docRoot} tag does not currently work in
overview documents.
Package Documentation Tags
Package tags are tags that can appear in the documentation
comment for a package (which resides in the source file named
package.html or package-info.java). The
@serial tag can only be used here with the include
or exclude argument.
Class and Interface Documentation Tags
The following are tags that can appear in the documentation
comment for a class or interface. The @serial tag can only
be used here with the include or exclude argument.
An example of a class comment:
/**
* A class representing a window on the screen.
* For example:
* <pre>
* Window win = new Window(parent);
* win.show();
* </pre>
*
* @author Sami Shaio
* @version 1.13, 06/08/06
* @see java.awt.BaseWindow
* @see java.awt.Button
*/
class Window extends BaseWindow {
...
}
Field Documentation Tags
The following are the tags that can appear in the documentation
comment for a field.
An example of a field comment:
/**
* The X-coordinate of the component.
*
* @see #getLocation()
*/
int x = 1263732;
Constructor and Method Documentation Tags
The following are the tags that can appear in the documentation
comment for a constructor or method, except for @return,
which cannot appear in a constructor, and {@inheritDoc},
which has certain restrictions. The @serialData tag can
only be used in the doc comment for certain serialization
methods.
An example of a method doc comment:
/**
* Returns the character at the specified index. An index
* ranges from <code>0</code> to <code>length()
- 1</code>.
*
* @param index the index of the desired character.
* @return the desired character.
* @exception StringIndexOutOfRangeException
* if the index is not in the range <code>0</code>
* to <code>length()-1</code>.
* @see java.lang.Character#charValue()
*/
public char charAt(int index) {
...
}
real world example
The Javadoc tool has many useful options, some of which are more
commonly used than others. Here is effectively the command we use
to run the Javadoc tool on the Java platform API. We use 180MB of
memory to generate the documentation for the 1500 (approx.)
public and protected classes in the Java 2 Platform, Standard
Edition, v1.2.
The same example is shown twice -- first as executed on the
command line, then as executed from a makefile. It uses absolute
paths in the option arguments, which enables the same
javadoc command to be run from any directory.
Command Line Example
This command line example is over 900 characters, which is too
long for some shells, such as DOS. You can use a command line
argument file (or write a shell script) to workaround this
limitation.
% javadoc -sourcepath /java/jdk/src/share/classes \
-overview /java/jdk/src/share/classes/overview.html \
-d /java/jdk/build/api \
-use \
-splitIndex \
-windowtitle ’Java 2 Platform 5.0 API Specification’ \
-doctitle ’Java<sup><font
size="-2">TM</font></sup> 2 Platform 5.0 API
Specification’ \
-header ’<b>Java 2 Platform </b><br><font
size="-1">5.0</font>’ \
-bottom ’<font size="-1"><a
href="http://java.sun.com/cgi-bin/bugreport.cgi">Submit
a bug or feature</a><br><br>Java is a trademark
or registered trademark of Sun Microsystems,
Inc. in the US and other countries.<br>Copyright 1993-1999
Sun Microsystems, Inc.
901 San Antonio Road,<br>Palo Alto, California, 94303,
U.S.A. All Rights Reserved.</font>’ \
-group "Core Packages" "java.*:com.sun.java.*:org.omg.*" \
-group "Extension Packages" "javax.*" \
-J-Xmx180m \
@packages
where packages is the name of a file containing the
packages to process, such as java.applet java.lang. None
of the options should contain any newline characters between the
single quotes. (For example, if you copy and paste this example,
delete the newline characters from the -bottom option.)
See the other notes listed below.
Makefile Example
This is an example of a GNU makefile. For an example of a Windows
makefile, see creating a makefile for Windows @
http://java.sun.com/j2se/javadoc/faq/index.html#makefiles.
javadoc -sourcepath $(SRCDIR) \ /* Sets path for source files
*/
-overview $(SRCDIR)/overview.html \ /* Sets file for overview
text */
-d /java/jdk/build/api \ /* Sets destination directory */
-use \ /* Adds "Use" files */
-splitIndex \ /* Splits index A-Z */
-windowtitle $(WINDOWTITLE) \ /* Adds a window title */
-doctitle $(DOCTITLE) \ /* Adds a doc title */
-header $(HEADER) \ /* Adds running header text */
-bottom $(BOTTOM) \ /* Adds text at bottom */
-group $(GROUPCORE) \ /* 1st subhead on overview page */
-group $(GROUPEXT) \ /* 2nd subhead on overview page */
-J-Xmx180m \ /* Sets memory to 180MB */
java.lang java.lang.reflect \ /* Sets packages to document */
java.util java.io java.net \
java.applet
WINDOWTITLE = ’Java 2 Platform v1.2 API Specification’
DOCTITLE = ’Java<sup><font
size="-2">TM</font></sup> 2 Platform v1.2 API
Specification’
HEADER = ’<b>Java 2 Platform </b><br><font
size="-1">v1.2</font>’
BOTTOM = ’<font size="-1"><a
href="http://java.sun.com/cgi-bin/bugreport.cgi">Submit
a bug or feature</a><br><br>Java is a trademark
or registered trademark
of Sun Microsystems, Inc. in the US and other
countries.<br>Copyright 1993-1999
Sun Microsystems, Inc. 901 San Antonio Road,<br>Palo Alto,
California, 94303, U.S.A.
All Rights Reserved.</font>’
GROUPCORE = ’"Core Packages"
"java.*:com.sun.java.*:org.omg.*"’
GROUPEXT = ’"Extension Packages" "javax.*"’
SRCDIR = ’/java/jdk/1.2/src/share/classes’
Single quotes are used to surround makefile arguments.
NOTES
o
If you omit the -windowtitle option, the Javadoc tool
copies the doc title to the window title. The -windowtitle
text is basically the same as the -doctitle but without
HTML tags, to prevent those tags from appearing as raw text in
the window title.
o
If you omit the -footer option, as done here, the Javadoc
tool copies the header text to the footer.
o
Other important options you might want to use but not needed in
this example are -classpath and -link.
running javadoc
Version Numbers - The version number of javadoc can be
determined using javadoc -J-version. The version number of
the standard doclet appears in its output stream. It can be
turned off with -quiet.
Public programmatic interface - To invoke the Javadoc tool
from within programs written in the Java language. This interface
is in com.sun.tools.javadoc.Main (and javadoc is
re-entrant). For more details, see Standard Doclet.
Running Doclets - The instructions given below are for
invoking the standard HTML doclet. To invoke a custom doclet, use
the -doclet and -docletpath options. For full, working examples
of running a particular doclet, see Running the MIF Doclet
@
http://java.sun.com/j2se/javadoc/mifdoclet/docs/mifdoclet.html#runningmifdoclet.
simple examples
You can run javadoc on entire packages or individual source
files. Each package name has a corresponding directory name. In
the following examples, the source files are located at
/home/src/java/awt/*.java. The destination directory is
/home/html.
Documenting One or More Packages
To document a package, the source files (*.java) for that
package must be located in a directory having the same name as
the package. If a package name is made up of several identifiers
(separated by dots, such as java.awt.color), each
subsequent identifier must correspond to a deeper subdirectory
(such as java/awt/color). You may split the source files
for a single package among two such directory trees located at
different places, as long as -sourcepath points to them
both -- for example src1/java/awt/color and
src2/java/awt/color.
You can run javadoc either by changing directories (with
cd) or by using -sourcepath option. The examples
below illustrate both alternatives.
o
Case 1 - Run recursively starting from one or more
packages - This example uses -sourcepath so javadoc can be
run from any directory and -subpackages (a new 1.4 option) for
recursion. It traverses the subpackages of the java
directory excluding packages rooted at java.net and
java.lang. Notice this excludes java.lang.ref, a
subpackage of java.lang).
% javadoc -d /home/html -sourcepath /home/src -subpackages
java -exclude java.net:java.lang
To also traverse down other package trees, append their names to
the -subpackages argument, such as
java:javax:org.xml.sax.
o
Case 2 - Run on explicit packages after changing to the "root"
source directory - Change to the parent directory of the
fully-qualified package. Then run javadoc, supplying names of one
or more packages you want to document:
% cd /home/src/
% javadoc -d /home/html java.awt java.awt.event
o
Case 3 - Run from any directory on explicit packages in a
single directory tree - In this case, it doesn’t matter what
the current directory is. Run javadoc supplying
-sourcepath with the parent directory of the top-level
package, and supplying names of one or more packages you want to
document:
% javadoc -d /home/html -sourcepath /home/src java.awt
java.awt.event
o
Case 4 - Run from any directory on explicit packages in
multiple directory trees - This is the same as case 3, but
for packages in separate directory trees. Run javadoc supplying
-sourcepath with the path to each tree’s root
(colon-separated) and supply names of one or more packages you
want to document. All source files for a given package do not
need to be located under a single root directory -- they just
need to be found somewhere along the sourcepath.
% javadoc -d /home/html -sourcepath /home/src1:/home/src2
java.awt java.awt.event
Result: All cases generate HTML-formatted documentation for the
public and protected classes and interfaces in packages
java.awt and java.awt.event and save the HTML files
in the specified destination directory (/home/html).
Because two or more packages are being generated, the document
has three HTML frames -- for the list of packages, the list of
classes, and the main class pages.
Documenting One or More Classes
The second way to run the Javadoc tool is by passing in one or
more source files (.java). You can run javadoc either of
the following two ways -- by changing directories (with
cd) or by fully-specifying the path to the .java
files. Relative paths are relative to the current directory. The
-sourcepath option is ignored when passing in source
files. You can use command line wildcards, such as asterisk (*),
to specify groups of classes.
o
Case 1 - Changing to the source directory - Change to the
directory holding the .java files. Then run javadoc,
supplying names of one or more source files you want to document.
% cd /home/src/java/awt
% javadoc -d /home/html Button.java Canvas.java
Graphics*.java
This example generates HTML-formatted documentation for the
classes Button, Canvas and classes beginning with
Graphics. Because source files rather than package names
were passed in as arguments to javadoc, the document has two
frames -- for the list of classes and the main page.
o
Case 2 - Changing to the package root directory - This is
useful for documenting individual source files from different
subpackages off the same root. Change to the package root
directory, and supply the source files with paths from the root.
% cd /home/src/
% javadoc -d /home/html java/awt/Button.java
java/applet/Applet.java
This example generates HTML-formatted documentation for the
classes Button and Applet.
o
Case 3 - From any directory - In this case, it doesn’t
matter what the current directory is. Run javadoc supplying the
absolute path (or path relative to the current directory) to the
.java files you want to document.
% javadoc -d /home/html /home/src/java/awt/Button.java
/home/src/java/awt/Graphics*.java
This example generates HTML-formatted documentation for the class
Button and classes beginning with Graphics.
Documenting Both Packages and Classes
You can document entire packages and individual classes at the
same time. Here’s an example that mixes two of the previous
examples. You can use -sourcepath for the path to the
packages but not for the path to the individual classes.
% javadoc -d /home/html -sourcepath /home/src java.awt
/home/src/java/applet/Applet.java
This example generates HTML-formatted documentation for the
package java.awt and class Applet. (The Javadoc
tool determines the package name for Applet from the
package declaration, if any, in the Applet.java source
file.)
source files
The Javadoc tool will generate output originating from four
different types of "source" files: Java language source files for
classes (.java), package comment files, overview comment
files, and miscellaneous unprocessed files. This section also
covers test files and template files that can also be in the
source tree, but which you want to be sure not to document.
Class Source Code Files
Each class or interface and its members can have their own
documentation comments, contained in a .java file. For
more details about these doc comments, see Documentation
Comments.
Package Comment Files
Each package can have its own documentation comment, contained in
its own "source" file, that the Javadoc tool will merge into the
package summary page that it generates. You typically include in
this comment any documentation that applies to the entire
package.
To create a package comment file, you have a choice of two files
to place your comments:
o
package-info.java - Can contain a package declaration,
package annotations, package comments and Javadoc tags. This file
is new in JDK 5.0, and is preferred over package.html.
o
package.html - Can contain only package comments and
Javadoc tags, no package annotations.
A package may have a single package.html file or a single
package-info.java file but not both. Place either file in
the package directory in the source tree along with your
.java files.
package-info.java This file can contain a package
comment of the following structure -- the comment is placed
before the package declaration:
File: java/applet/package-info.java
Note that while the comment separators /** and /*
must be present, the leading asterisks on the intermediate lines
can be omitted.
package.html - This file can contain a package
comment of the following structure -- the comment is placed in
the <body> element:
File: java/applet/package.html
Notice this is just a normal HTML file and does not include a
package declaration. The content of the package comment file is
written in HTML, like all other comments, with one exception: The
documentation comment should not include the comment separators
/** and */ or leading asterisks. When writing the
comment, you should make the first sentence a summary about the
package, and not put a title or any other text between
<body> and the first sentence. You can include
package tags; as with any documentation comment, all block tags
must appear after the main description. If you add a @see
tag in a package comment file, it must have a fully-qualified
name. For more details, see the example of package.html
@
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html#packagecomments.
Processing of package comment file - When the Javadoc tool
runs, it will automatically look for the package comment file; if
found, the Javadoc tool does the following:
o
Copies the comment for processing. (For package.html,
copies all content between <body> and
</body> HTML tags. You can include a
<head> section to put a <title>, source
file copyright statement, or other information, but none of these
will appear in the generated documentation.)
o
Processes any package tags that are present.
o
Inserts the processed text at the bottom of the package summary
page it generates, as shown in Package Summary.
o
Copies the first sentence of the package comment to the top of
the package summary page. It also adds the package name and this
first sentence to the list of packages on the overview page, as
shown in Overview Summary. The end-of-sentence is determined by
the same rules used for the end of the first sentence of class
and member main descriptions.
Overview Comment File
Each application or set of packages that you are documenting can
have its own overview documentation comment, kept in its own
"source" file, that the Javadoc tool will merge into the overview
page that it generates. You typically include in this comment any
documentation that applies to the entire application or set of
packages.
To create an overview comment file, you can name the file
anything you want, typically overview.html and
place it anywhere, typically at the top level of the source tree.
For example, if the source files for the java.applet
package are contained in /home/user/src/java/applet
directory, you could create an overview comment file at
/home/user/src/overview.html.
Notice you can have multiple overview comment files for the same
set of source files, in case you want to run javadoc multiple
times on different sets of packages. For example, you could run
javadoc once with -private for internal documentation and again
without that option for public documentation. In this case, you
could describe the documentation as public or internal in the
first sentence of each overview comment file.
The content of the overview comment file is one big documentation
comment, written in HTML, like the package comment file described
previously. See that description for details. To re-iterate, when
writing the comment, you should make the first sentence a summary
about the application or set of packages, and not put a title or
any other text between <body> and the first
sentence. You can include overview tags; as with any
documentation comment, all tags except in-line tags, such as
{@link}, must appear after the main description. If you
add a @see tag, it must have a fully-qualified name.
When you run the Javadoc tool, you specify the overview comment
file name with the -overview option. The file is then processed
similar to that of a package comment file.
o
Copies all content between <body> and
</body> tags for processing.
o
Processes any overview tags that are present.
o
Inserts the processed text at the bottom of the overview page it
generates, as shown in Overview Summary.
o
Copies the first sentence of the overview comment to the top of
the overview summary page.
Miscellaneous Unprocessed Files
You can also include in your source any miscellaneous files that
you want the Javadoc tool to copy to the destination directory.
These typically includes graphic files, example Java source
(.java) and class (.class) files, and self-standing HTML files
whose content would overwhelm the documentation comment of a
normal Java source file.
To include unprocessed files, put them in a directory called
doc-files which can be a subdirectory of any
package directory that contains source files. You can have one
such subdirectory for each package. You might include images,
example code, source files, .class files, applets and HTML files.
For example, if you want to include the image of a button
button.gif in the java.awt.Button class
documentation, you place that file in the
/home/user/src/java/awt/doc-files/ directory. Notice the
doc-files directory should not be located at
/home/user/src/java/doc-files because java is not a
package -- that is, it does not directly contain any source
files.
All links to these unprocessed files must be hard-coded, because
the Javadoc tool does not look at the files -- it simply copies
the directory and all its contents to the destination. For
example, the link in the Button.java doc comment might
look like:
/**
* This button looks like this:
* <img src="doc-files/Button.gif">
*/
Test Files and Template Files
Some developers have indicated they want to store test files and
templates files in the source tree near their corresponding
source files. That is, they would like to put them in the same
directory, or a subdirectory, of those source files.
If you run the Javadoc tool by explicitly passing in individual
source filenames, you can deliberately omit test and templates
files and prevent them from being processed. However, if you are
passing in package names or wildcards, you need to follow certain
rules to ensure these test files and templates files are not
processed.
Test files differ from template files in that the former are
legal, compilable source files, while the latter are not, but may
end with ".java".
Test files - Often developers want to put compilable,
runnable test files for a given package in the same
directory as the source files for that package. But they want the
test files to belong to a package other than the source file
package, such as the unnamed package (so the test files have no
package statement or a different package statement from the
source). In this scenario, when the source is being documented by
specifying its package name specified on the command line, the
test files will cause warnings or errors. You need to put such
test files in a subdirectory. For example, if you want to add
test files for source files in com.package1, put them in a
subdirectory that would be an invalid package name (because it
contains a hyphen):
com/package1/test-files/
The test directory will be skipped by the Javadoc tool with no
warnings.
If your test files contain doc comments, you can set up a
separate run of the Javadoc tool to produce documentation of the
test files by passing in their test source filenames with
wildcards, such as com/package1/test-files/*.java.
Templates for source files - Template files have names
that often end in ".java" and are not compilable. If you have a
template for a source file that you want to keep in the source
directory, you can name it with a dash (such as
Buffer-Template.java), or any other illegal Java
character, to prevent it from being processed. This relies on the
fact that the Javadoc tool will only process source files whose
name, when stripped of the ".java" suffix, is actually a legal
class name (see Identifiers @
http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#40625).
troubleshooting
General Troubleshooting
o
Javadoc FAQ - Commonly-encountered bugs and
troubleshooting tips can be found on the Javadoc FAQ @
http://java.sun.com/j2se/javadoc/faq/index.html#B
o
Bugs and Limitations - You can also see some bugs listed
at Important Bug Fixes and Changes @
http://java.sun.com/j2se/1.5.0/fixedbugs/index.html.
o
Version number - See version numbers.
o
Documents only legal classes - When documenting a package,
javadoc only reads files whose names are composed of legal class
names. You can prevent javadoc from parsing a file by including,
for example, a hyphen "-" in its filename.
Errors and Warnings
Error and warning messages contain the filename and line number
to the declaration line rather than to the particular line in the
doc comment.
o
"error: cannot read: Class1.java" the Javadoc tool is
trying to load the class Class1.java in the current directory.
The class name is shown with its path (absolute or relative),
which in this case is the same as ./Class1.java.
see also
o
javac
o
java
o
jdb
o
javah
o
javap
o
Javadoc Home Page @
http://java.sun.com/j2se/javadoc/index.jsp
o
How to Write Doc Comments for
Javadoc @
http://java.sun.com/j2se/javadoc/writingdoccomments/index.html
o
Setting the Class Path
o
How Javac and Javadoc Find Classes (tools.jar)
Javadoc is a
trademark of Sun Microsystems, Inc. (The javadoc
command itself does not require the trademark symbol.)