1jar(1) General Commands Manual jar(1)
2
6 jar-The Java Archive Tool
7 jar combines multiple files into a single JAR archive file.
9
11 Create jar file
12 jar c[v0Mmfe] [manifest] [jarfile] [entrypoint] [-C dir] inputfiles
13 [-Joption]
14 Update jar file
16 jar u[v0Mmfe] [manifest] [jarfile] [entrypoint] [-C dir] inputfiles
17 [-Joption]
18 Extract jar file
20 jar x[vf] [jarfile] [inputfiles] [-Joption]
21 List table of contents of jar file
23 jar t[vf] [jarfile] [inputfiles] [-Joption]
24 Add index to jar file
26 jar i jarfile [-Joption]
27 where:
29 cuxtiv0Mmfe
31 Options that control the jar command.
32 jarfile
34 Jar file to be created (c), updated (u), extracted (x), or have
35 its table of contents viewed (t). The -f option and filename
36 jarfile are a pair -- if either is present, they must both
37 appear. Note that omitting f and jarfile accepts a "jar file"
38 from standard input (for x and t) or sends the "jar file" to
39 standard output (for c and u).
40 inputfiles
43 Files or directories, separated by spaces, to be combined into
44 jarfile (for c and u), or to be extracted (for x) or listed (for
45 t) from jarfile. All directories are processed recursively. The
46 files are compressed unless option 0 (zero) is used.
47 manifest
49 Pre-existing manifest file whose name: value pairs are to be
50 included in MANIFEST.MF in the jar file. The -m option and file‐
51 name manifest are a pair -- if either is present, they must both
52 appear. The letters m, f and e must appear in the same order that
53 manifest, jarfile, entrypoint appear.
54 entrypoint
57 The name of the class that set as the application entry point for
58 stand-alone applications bundled into executable jar file. The -e
59 option and entrypoint are a pair -- if either is present, they
60 must both appear. The letters m, f and e must appear in the same
61 order that manifest, jarfile, entrypoint appear.
62 -C dir
64 Temporarily changes directories to dir while processing the fol‐
65 lowing inputfiles argument. Multiple -C dir inputfiles sets are
66 allowed.
67 -Joption
69 Option to be passed into the Java runtime environment. (There
70 must be no space between -J and option).
71
73 The jar tool combines multiple files into a single JAR archive file.
74 jar is a general-purpose archiving and compression tool, based on ZIP
75 and the ZLIB @
76 http://www.gzip.org/zlib/ compression format. However, jar was designed
77 mainly package java applets or applications into a single archive. When
78 the components of an applet or application (files, images and sounds)
79 are combined into a single archive, they can be downloaded by a java
80 agent (like a browser) in a single HTTP transaction, rather than
81 requiring a new connection for each piece. This dramatically improves
82 download times. jar also compresses files and so further improves down‐
83 load time. In addition, it allows individual entries in a file to be
84 signed by the applet author so that their origin can be authenticated.
85 The syntax for the jar tool is almost identical to the syntax for the
86 tar command. A jar archive can be used as a class path @
87 http://ccc.sfbay/4291383/attachment/classpath.html entry, whether or
88 not it is compressed.
89 Typical usage to combine files into a jar file is:
91 % jar cf myFile.jar *.class
93 In this example, all the class files in the current directory are
96 placed into the file named myFile.jar. The jar tool automatically gen‐
97 erates a manifest file entry named META-INF/MANIFEST.MF. It is always
98 the first entry in the jar file. The manifest file declares meta-infor‐
99 mation about the archive, and stores that data as name : value pairs.
100 Refer to the JAR file specification @
101 http://ccc.sfbay/guide/jar/jar.html#JAR%20Manifest for details explain‐
102 ing how the jar tool stores meta-information in the manifest file.
103 If a jar file should include name : value pairs contained in an exist‐
105 ing manifest file, specify that file using the -m option:
106 % jar cmf myManifestFile myFile.jar *.class
108 An existing manifest file must end with a new line character. jar does
111 not parse the last line of a manifest file if it does not end with a
112 new line character.
113 Note: A jar command that specifies cfm on the command line instead of
116 cmf (the order of the m and -f options are reversed), the jar command
117 line must specify the name of the jar archive first, followed by the
118 name of the manifest file:
119 % jar cfm myFile.jar myManifestFile *.class
122 The manifest is in a text format inspired by RFC822 ASCII format, so it
125 is easy to view and process manifest-file contents.
126 To extract the files from a jar file, use x:
128 % jar xf myFile.jar
130 To extract individual files from a jar file, supply their filenames:
133 % jar xf myFile.jar foo bar
135 Beginning with version 1.3 of the Java 2 SDK, the jar utility supports
138 JarIndex @
139 http://ccc.sfbay/guide/jar/jar.html#JAR%20Index, which allows applica‐
140 tion class loaders to load classes more efficiently from jar files. If
141 an application or applet is bundled into multiple jar files, only the
142 necessary jar files will be downloaded and opened to load classes. This
143 performance optimization is enabled by running jar with the -ioption.
144 It will generate package location information for the specified main
145 jar file and all the jar files it depends on, which need to be speci‐
146 fied in the Class-Path attribute of the main jar file's manifest.
147 % jar i main.jar
149 In this example, an INDEX.LIST file is inserted into the META-INF
152 directory of main.jar.
153 The application class loader uses the information stored in this file
154 for efficient class loading. For details about how location informa‐
155 tion is stored in the index file, refer to the JarIndex specification.
156 To copy directories, first compress files in dir1 to stdout, then
157 extract from stdin to dir2 (omitting the -f option from both jar com‐
158 mands):
159 % (cd dir1; jar c .) | (cd dir2; jar x)
161 To review command samples which use jar to opeate on jar files and jar
164 file manifests, see Examples, below. Also refer to the jar trail of the
165 Java Tutorial @
166 http://java.sun.com/docs/books/tutorial/jar.
167
169 c Creates a new archive file named jarfile (if f is specified) or to
170 standard output (if f and jarfile are omitted). Add to it the files
171 and directories specified by inputfiles.
172 u Updates an existing file jarfile (when f is specified) by adding to
174 it files and directories specified by inputfiles. For example:
175 jar uf foo.jar foo.class
178 would add the file foo.class to the existing jar file foo.jar. The -u
179 option can also update the manifest entry, as given by this example:
180 jar umf manifest foo.jar
183 updates the foo.jar manifest with the name : value pairs in manifest.
184 x Extracts files and directories from jarfile (if f is specified) or
186 standard input (if f and jarfile are omitted). If inputfiles is
187 specified, only those specified files and directories are extracted.
188 Otherwise, all files and directories are extracted. The time and
189 date of the extracted files are those given in the archive.
190 t Lists the table of contents from jarfile (if f is specified) or
192 standard input (if f and jarfile are omitted). If inputfiles is
193 specified, only those specified files and directories are listed.
194 Otherwise, all files and directories are listed.
195 i Generate index information for the specified jarfile and its depen‐
197 dent jar files. For example:
198 jar i foo.jar
201 would generate an INDEX.LIST file in foo.jar which contains location
203 information for each package in foo.jar and all the jar files specified
204 in the Class-Path attribute of foo.jar. See the index example.
205 f Specifies the file jarfile to be created (c), updated (u), extracted
207 (x), indexed (i), or viewed (t). The -f option and filename jarfile
208 are a pair -- if present, they must both appear. Omitting f and
209 jarfile accepts a jar file name from stdin(for x and t) or sends jar
210 file to stdout (for c and u).
211 v Generates verbose output to standard output. Examples shown below.
213 0 (zero) Store without using ZIP compression.
215 M Do not create a manifest file entry (for c and u), or delete a mani‐
217 fest file entry if one exists (for u).
218 m Includes name : value attribute pairs from the specified manifest
220 file manifest in the file at META-INF/MANIFEST.MF. jar adds a
221 name : value pair unless an entry already exists with the same name,
222 in which case jar updates its value.
223 On the command line, the letters m and f must appear in the same order
225 that manifest and jarfile appear. Example use:
226 jar cmf myManifestFile myFile.jar *.class
229 You can add special-purpose name : value attribute pairs to the mani‐
230 fest that aren't contained in the default manifest. For example, you
231 can add attributes specifying vendor information, version information,
232 package sealing, or to make JAR-bundled applications executable. See
233 the JAR Files @
234 http://java.sun.com/docs/books/tutorial/jar/ trail in the Java Tutorial
235 for examples of using the -m option.
236 e Sets entrypoint as the application entry point for stand-alone
238 applications bundled into executable jar file. The use of this
239 option creates or overrides the Main-Class attribute value in the
240 manifest file. This option can be used during creation of jar file
241 or while updating the jar file. This option specifies the applica‐
242 tion entry point without editing or creating the manifest file.
243 For example, this command creates Main.jar where the Main-Class
244 attribute value in the manifest is set to Main:
245 jar cfe Main.jar Main Main.class
248 The java runtime can directly invoke this application by running the
250 following command:
251 java -jar Main.jar
254 If the entrypoint class name is in a package it may use either a dot
255 (".") or slash ("/") character as the delimiter. For example, if
256 Main.class is in a package called foo the entry point can be specified
257 in the following ways:
258 jar -cfe Main.jar foo/Main foo/Main.class
261 or
262 jar -cfe Main.jar foo.Main foo/Main.class
265 Note: specifying both -m and -e options together when the given mani‐
266 fest also contains the Main-Class attribute results in an ambigous
267 Main.class specification, leading to an error and the jar creation or
268 update operation is aborted.
269 -C dir
271 Temporarily changes directories (cd dir) during execution of the jar
272 command while processing the following inputfiles argument. Its
273 operation is intended to be similar to the -C option of the UNIX tar
274 utility.
275 For example, this command changes to the classes directory and adds
276 the bar.class from that directory to foo.jar:
277 jar uf foo.jar -C classes bar.class
280 This command changes to the classes directory and adds to foo.jar all
281 files within the classes directory (without creating a classes direc‐
282 tory in the jar file), then changes back to the original directory
283 before changing to the bin directory to add xyz.class to foo.jar.
284 jar uf foo.jar -C classes . -C bin xyz.class
287 If classes holds files bar1 and bar2, then here's what the jar file
288 will contain using jar tf foo.jar:
289 META-INF/
292 META-INF/MANIFEST.MF
293 bar1
294 bar2
295 xyz.class
296 -Joption
298 Pass option to the Java runtime environment, where option is one of
299 the options described on the reference page for the java application
300 launcher @
301 http://ccc.sfbay/4291383/attachment/java.html#options. For example,
302 -J-Xmx48M sets the maximum memory to 48 megabytes. It is a common
303 convention for -J to pass options to the underlying runtime environ‐
304 ment.
305
307 To shorten or simplify the jar command line, you can specify one or
308 more files that themselves contain arguments to the jar command (except
309 -J options). This enables you to create jar commands of any length,
310 overcoming command line limits imposed by the operating system.
311 An argument file can include options and filenames. The arguments
313 within a file can be space–separated or newline-separated. File‐
314 names within an argument file are relative to the current directory,
315 not relative to the location of the argument file. Wildcards (*) that
316 might otherwise be expanded by the operating system shell are not
317 expanded. Use of the @ character to recursively interpret files is not
318 supported. The -J options are not supported because they are passed to
319 the launcher, which does not support argument files.
320 When executing jar, pass in the path and name of each argument file
322 with the @ leading character. When jar encounters an argument beginning
323 with the character @, it expands the contents of that file into the
324 argument list.
325 The example below, classes.list holds the names of files output by a
326 find command:
327 % find . -name '*.class' -print > classes.list
329 You can then execute the jar command on Classes.list by passing it to
332 jar using argfile syntax:
333 % jar cf my.jar @classes.list
335 An argument file can specify a path, but any filenames inside the argu‐
338 ment file that have relative paths are relative to the current working
339 directory, not to the path passed in. Here is an example:
340 % jar @path1/classes.list
343
346 To add all the files in a particular directory to an archive (overwrit‐
347 ing contents if the archive already exists). Enumerating verbosely
348 (with the -v option) will tell you more information about the files in
349 the archive, such as their size and last modified date.
350 % ls
353 1.au Animator.class monkey.jpg
354 2.au Wave.class spacemusic.au
355 3.au at_work.gif
356 % jar cvf bundle.jar *
358 added manifest
359 adding: 1.au(in = 2324) (out= 67)(deflated 97%)
360 adding: 2.au(in = 6970) (out= 90)(deflated 98%)
361 adding: 3.au(in = 11616) (out= 108)(deflated 99%)
362 adding: Animator.class(in = 2266) (out= 66)(deflated 97%)
363 adding: Wave.class(in = 3778) (out= 81)(deflated 97%)
364 adding: at_work.gif(in = 6621) (out= 89)(deflated 98%)
365 adding: monkey.jpg(in = 7667) (out= 91)(deflated 98%)
366 adding: spacemusic.au(in = 3079) (out= 73)(deflated 97%)
367 If you already have separate subdirectories for images, audio files and
370 classes, you can combine them into a single jar file:
371 % ls -F
374 audio/ classes/ images/
375 % jar cvf bundle.jar audio classes images
377 added manifest
378 adding: audio/(in = 0) (out= 0)(stored 0%)
379 adding: audio/1.au(in = 2324) (out= 67)(deflated 97%)
380 adding: audio/2.au(in = 6970) (out= 90)(deflated 98%)
381 adding: audio/3.au(in = 11616) (out= 108)(deflated 99%)
382 adding: audio/spacemusic.au(in = 3079) (out= 73)(deflated 97%)
383 adding: classes/(in = 0) (out= 0)(stored 0%)
384 adding: classes/Animator.class(in = 2266) (out= 66)(deflated 97%)
385 adding: classes/Wave.class(in = 3778) (out= 81)(deflated 97%)
386 adding: images/(in = 0) (out= 0)(stored 0%)
387 adding: images/monkey.jpg(in = 7667) (out= 91)(deflated 98%)
388 adding: images/at_work.gif(in = 6621) (out= 89)(deflated 98%)
389 % ls -F
391 audio/ bundle.jar classes/ images/
392 To see the entry names in the jarfile, use the t option:
395 % jar tf bundle.jar
398 META-INF/
399 META-INF/MANIFEST.MF
400 audio/1.au
401 audio/2.au
402 audio/3.au
403 audio/spacemusic.au
404 classes/Animator.class
405 classes/Wave.class
406 images/monkey.jpg
407 images/at_work.gif
408 To add an index file to the jar file for speeding up class loading, use
411 the i option.
412 Example:
413 If you split the inter-dependent classes for a stock trade applica‐
416 tion into three jar files: main.jar, buy.jar, and sell.jar.
417 If you specify the Class-path attribute in the main.jar manifest as:
420 Class-Path: buy.jar sell.jar
421 then you can use the -i option to speed up the class loading time
424 for your application:
425 % jar i main.jar
426 An INDEX.LIST file is inserted to the META-INF directory. This
429 enables the application class loader to download the specified jar
430 files when it is searching for classes or resources.
431
433 The Jar Overview @
434 http://ccc.sfbay/guide/jar/jarGuide.html
435 The Jar File Specification @
438 http://ccc.sfbay/guide/jar/jar.html
439 The JarIndex Spec @
442 http://ccc.sfbay/guide/jar/jar.html#JAR%20Index
443 Jar Tutorial @
446 http://java.sun.com/docs/books/tutorial/jar on the Java Software web
447 site.
448 pack200 Reference Page @
451 http://ccc.sfbay/4291383/share/pack200.html
452 05 Aug 2006 jar(1)