The Java Archive Tool jar combines multiple files into a single JAR archive file.
[manifest] [jarfile] [entrypoint] [-C dir] inputfiles
Update jar file
[manifest] [jarfile] [entrypoint] [-C dir] inputfiles
Extract jar file
[jarfile] [inputfiles] [-Joption]
List table of contents of jar
[jarfile] [inputfiles] [-Joption]
Add index to jar file
jar i jarfile
Options that control the
Jar file to be created
(c), updated (u), extracted (x), or
have its table of contents viewed (t). The
-f option and filename jarfile are a
pair -- if either is present, they must both
appear. Note that omitting f and jarfile
accepts a "jar file" from standard input (for x
and t) or sends the "jar file" to standard output
(for c and u).
Files or directories, separated
by spaces, to be combined into jarfile (for c and u),
or to be extracted (for x) or listed (for t) from
jarfile. All directories are processed recursively.
The files are compressed unless option 0 (zero) is
file whose name: value pairs are to be included in
MANIFEST.MF in the jar file. The -m option and
filename manifest are a pair -- if either
is present, they must both appear. The letters m,
f and e must appear in the same order that
manifest, jarfile, entrypoint
The name of the class that set
as the application entry point for stand-alone
applications bundled into executable jar file. The
-e option and entrypoint are a pair
-- if either is present, they must both appear.
The letters m, f and e must appear in
the same order that manifest, jarfile,
Temporarily changes directories
to dir while processing the following
inputfiles argument. Multiple -C dir
inputfiles sets are allowed.
Option to be passed into the
Java runtime environment. (There must be no space between
-J and option).
add an example, a script, a trick and tips
To add all the files in a particular directory to an archive
(overwriting contents if the archive already exists). Enumerating
verbosely (with the -v option) will tell you more
information about the files in the archive, such as their size
and last modified date.
1.au Animator.class monkey.jpg
2.au Wave.class spacemusic.au
% jar cvf bundle.jar *
adding: 1.au(in = 2324) (out= 67)(deflated 97%)
adding: 2.au(in = 6970) (out= 90)(deflated 98%)
adding: 3.au(in = 11616) (out= 108)(deflated 99%)
adding: Animator.class(in = 2266) (out= 66)(deflated 97%)
adding: Wave.class(in = 3778) (out= 81)(deflated 97%)
adding: at_work.gif(in = 6621) (out= 89)(deflated 98%)
adding: monkey.jpg(in = 7667) (out= 91)(deflated 98%)
adding: spacemusic.au(in = 3079) (out= 73)(deflated 97%)
If you already have separate subdirectories for images, audio
files and classes, you can combine them into a single jar file:
% ls -F
audio/ classes/ images/
% jar cvf bundle.jar audio classes images
adding: audio/(in = 0) (out= 0)(stored 0%)
adding: audio/1.au(in = 2324) (out= 67)(deflated 97%)
adding: audio/2.au(in = 6970) (out= 90)(deflated 98%)
adding: audio/3.au(in = 11616) (out= 108)(deflated 99%)
adding: audio/spacemusic.au(in = 3079) (out= 73)(deflated
adding: classes/(in = 0) (out= 0)(stored 0%)
adding: classes/Animator.class(in = 2266) (out= 66)(deflated
adding: classes/Wave.class(in = 3778) (out= 81)(deflated 97%)
adding: images/(in = 0) (out= 0)(stored 0%)
adding: images/monkey.jpg(in = 7667) (out= 91)(deflated 98%)
adding: images/at_work.gif(in = 6621) (out= 89)(deflated 98%)
% ls -F
audio/ bundle.jar classes/ images/
To see the entry names in the jarfile, use the t option:
% jar tf bundle.jar
To add an index file to the jar file for speeding up class
loading, use the i option.
If you split the inter-dependent classes for a stock trade
application into three jar files: main.jar,
buy.jar, and sell.jar.
If you specify the Class-path attribute in the
main.jar manifest as:
Class-Path: buy.jar sell.jar
then you can use the -i option to speed up the class
loading time for your application:
% jar i main.jar
An INDEX.LIST file is inserted to the META-INF
directory. This enables the application class loader to download
the specified jar files when it is searching for classes or
How do I delete the meta-inf folder in minecraft.jar?
p7zip couldn't open it for me even after renaming it
to zip (said "unknown suffix").
My system's default archive manager is
it opened the .jar witout any problems an I could delete the
unzip could also handle it, but you need to
recompress manually after.
How to replace a file in jar with command line in linux?
zip -u stuff.jar file.txt
will update file.txt in stuff.zip . Note that for
file.txt must already exist in the zip file, and will only be
overwritten if it's newer than the one in the jar.
Eclipse with JAR - Classpath on OpenSuse 12.1
you have to open the project properties (right click on project
and then select "build path"->"configure build path" .
Afterwards, you'll see a screen like this one:
Click on "Add JARs" on the right if you want to add a JAR that
resides inside your project or alternativly click on "Add
External JARs" if they're located just somewhere on your hard
disk. The first option is preferable though.
Is there a way to edit files inside of a zip file without explicitly extracting them first?
Short answer: NO.
If it's a wrapper, you are calling these commands.
Anyway, the best I can think of is to open the file using
file-roller, if you are in an X environment, that
might work with a simple double click, depending on your setup.
You can then double click on the compressed file to open it and
then you can edit it:
$ file-roller b3.zip
When you save your edited file, you should get this dialog:
You could make a script for this also, but that gets complicated
if you have compressed archives that contain multiple files. Let
me know if that's what you need and I might be able to cook
Editing a .jar with `vim`
However after selecting a file (eg. AbstractComponent.class)
and press Enter, within vim I get:
caution: filename not matched
This is probably a known bug in vim's ZIP plugin - the plugin
does not properly handle ZIP files that contain ZIP comments. See
e.g. this mailing list post
As a side note, I also noticed that if I extract the jar
(either with unzip or jar) and open an extracted file with vim,
the contents are misformatted
This is because most files inside a JAR are compiled Java class
files (file suffix
.class). These are binary data,
and vim is not really suitable for editing them, because vim is a
text editor, not a binary editor.
You can edit them in vim using the
xxd command (see
"Using xxd" in the vim docs), or you can use a hex editor, such as
At any rate, directly viewing the contents of a class file is
rarely helpful, as you need to understand the binary class file
format to read them.
Could you explain why you are trying to open files inside a JAR?
Then maybe we can help.
Execute a jar with double click in linux
There's a nice solution which causes Java jar files to be treated
as an executable without requiring shell scripts, although it's a
little fiddly to set up:
I believe that popular distros have packages that will sort it
out for you, although I've not used it myself recently.
tool combines multiple files into a single JAR archive file.
jar is a general-purpose archiving and
compression tool, based on ZIP and the ZLIB @
http://www.gzip.org/zlib/ compression format. However,
jar was designed mainly package java applets or
applications into a single archive. When the components of
an applet or application (files, images and sounds) are
combined into a single archive, they can be downloaded by a
java agent (like a browser) in a single HTTP transaction,
rather than requiring a new connection for each piece. This
dramatically improves download times. jar also
compresses files and so further improves download time. In
addition, it allows individual entries in a file to be
signed by the applet author so that their origin can be
authenticated. The syntax for the jar tool is almost
identical to the syntax for the tar command. A
jar archive can be used as a class path @
whether or not it is compressed.
to combine files into a jar file is:
% jar cf
example, all the class files in the current directory are
placed into the file named myFile.jar. The jar tool
automatically generates a manifest file entry named
META-INF/MANIFEST.MF. It is always the first
entry in the jar file. The manifest file declares
meta-information about the archive, and stores that
data as name : value pairs. Refer to the
JAR file specification @
details explaining how the jar tool stores
meta-information in the manifest file.
If a jar file
should include name : value pairs contained
in an existing manifest file, specify that file using the
% jar cmf
myManifestFile myFile.jar *.class
manifest file must end with a new line character.
jar does not parse the last line of a manifest file
if it does not end with a new line character.
A jar command that specifies cfm on the command line
instead of cmf (the order of the m and -f
options are reversed), the jar command line must
specify the name of the jar archive first, followed by the
name of the manifest file:
% jar cfm
myFile.jar myManifestFile *.class
The manifest is
in a text format inspired by RFC822 ASCII format, so it is
easy to view and process manifest-file contents.
To extract the
files from a jar file, use x:
% jar xf
individual files from a jar file, supply their
% jar xf
myFile.jar foo bar
version 1.3 of the Java 2 SDK, the jar utility
supports JarIndex @
allows application class loaders to load classes more
efficiently from jar files. If an application or applet is
bundled into multiple jar files, only the necessary
jar files will be downloaded and opened to load classes.
This performance optimization is enabled by running
jar with the -ioption. It will generate
package location information for the specified main jar file
and all the jar files it depends on, which need to be
specified in the Class-Path attribute of the
main jar file’s manifest.
% jar i
example, an INDEX.LIST file is inserted into the
META-INF directory of main.jar.
The application class loader uses the information stored in
this file for efficient class loading. For details
about how location information is stored in the index file,
refer to the JarIndex specification.
To copy directories, first compress files in dir1 to
stdout, then extract from stdin to dir2
(omitting the -f option from both jar
% (cd dir1;
jar c .) | (cd dir2; jar x)
command samples which use jar to opeate on jar files
and jar file manifests, see Examples, below. Also refer to
the jar trail of the Java Tutorial @
Creates a new archive file named
jarfile (if f is specified) or to standard
output (if f and jarfile are omitted). Add to
it the files and directories specified by
Updates an existing file jarfile (when f
is specified) by adding to it files and directories
specified by inputfiles. For example:
would add the file
foo.class to the existing jar file foo.jar.
The -u option can also update the manifest
entry, as given by this example:
updates the foo.jar
manifest with the name : value pairs in
Extracts files and directories
from jarfile (if f is specified) or standard
input (if f and jarfile are omitted). If
inputfiles is specified, only those specified files
and directories are extracted. Otherwise, all files and
directories are extracted. The time and date of the
extracted files are those given in the archive.
Lists the table of contents from jarfile (if
f is specified) or standard input (if f and
jarfile are omitted). If inputfiles is
specified, only those specified files and directories are
listed. Otherwise, all files and directories are listed.
Generate index information for the specified
jarfile and its dependent jar files. For example:
an INDEX.LIST file in foo.jar which contains
location information for each package in foo.jar and
all the jar files specified in the Class-Path
attribute of foo.jar. See the index example.
Specifies the file
jarfile to be created (c), updated (u),
extracted (x), indexed (i), or viewed
(t). The -f option and filename
jarfile are a pair -- if present, they
must both appear. Omitting f and jarfile
accepts a jar file name from stdin(for x and t) or
sends jar file to stdout (for c and u).
Generates verbose output to standard output. Examples
(zero) Store without using ZIP compression.
Do not create a manifest file entry (for c and u), or
delete a manifest file entry if one exists (for u).
Includes name : value attribute pairs from the
specified manifest file manifest in the file at
META-INF/MANIFEST.MF. jar adds a
name : value pair unless an entry already
exists with the same name, in which case jar updates
On the command
line, the letters m and f must appear in the
same order that manifest and jarfile appear.
myManifestFile myFile.jar *.class
You can add
special-purpose name : value
attribute pairs to the manifest that aren’t contained
in the default manifest. For example, you can add attributes
specifying vendor information, version information, package
sealing, or to make JAR-bundled applications
executable. See the JAR Files @
http://java.sun.com/docs/books/tutorial/jar/ trail in the
Java Tutorial for examples of using the
Sets entrypoint as the
application entry point for stand-alone applications
bundled into executable jar file. The use of this option
creates or overrides the Main-Class attribute
value in the manifest file. This option can be used during
creation of jar file or while updating the jar file. This
option specifies the application entry point without editing
or creating the manifest file.
For example, this command
creates Main.jar where the Main-Class
attribute value in the manifest is set to Main:
Main.jar Main Main.class
runtime can directly invoke this application by running the
If the entrypoint class name is
in a package it may use either a dot (".") or
slash ("/") character as the delimiter. For
example, if Main.class is in a package called
foo the entry point can be specified in the following
-cfe Main.jar foo/Main foo/Main.class
-cfe Main.jar foo.Main foo/Main.class
both -m and -e options together
when the given manifest also contains the
Main-Class attribute results in an ambigous
Main.class specification, leading to an error and the
jar creation or update operation is aborted.
Temporarily changes directories
(cd dir) during execution of the jar
command while processing the following inputfiles
argument. Its operation is intended to be similar to the
-C option of the UNIX tar utility.
For example, this command changes to the classes
directory and adds the bar.class from that directory
foo.jar -C classes bar.class
This command changes to the
classes directory and adds to foo.jar all
files within the classes directory (without creating
a classes directory in the jar file), then changes back to
the original directory before changing to the bin
directory to add xyz.class to foo.jar.
foo.jar -C classes . -C bin xyz.class
If classes holds files
bar1 and bar2, then here’s what the jar
file will contain using jar tf foo.jar:
Pass option to the Java
runtime environment, where option is one of the
options described on the reference page for the java
application launcher @
example, -J-Xmx48M sets the
maximum memory to 48 megabytes. It is a common convention
for -J to pass options to the underlying
command line argument files
To shorten or simplify the jar command line, you can specify one
or more files that themselves contain arguments to the jar
command (except -J options). This enables you to create
jar commands of any length, overcoming command line limits
imposed by the operating system.
An argument file can include options and filenames. The arguments
within a file can be space–separated or
newline-separated. Filenames within an argument file are relative
to the current directory, not relative to the location of the
argument file. Wildcards (*) that might otherwise be expanded by
the operating system shell are not expanded. 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 jar, pass in the path and name of each
argument file with the @ leading character. When
jar encounters an argument beginning with the character
@, it expands the contents of that file into the argument
The example below, classes.list holds the names of files
output by a find command:
% find . -name ’*.class’ -print >
You can then execute the jar command on
Classes.list by passing it to jar using argfile
% jar cf my.jar @classes.list
An argument file can specify a path, but any filenames inside the
argument file that have relative paths are relative to the
current working directory, not to the path passed in. Here is an
% jar @path1/classes.list
The Jar File
http://java.sun.com/docs/books/tutorial/jar on the Java
Software web site.
Reference Page @