Jar

Description

Jars a set of files.

The basedir attribute is the reference directory from where to jar.

Note that file permissions will not be stored in the resulting jarfile.

It is possible to refine the set of files that are being jarred. This can be done with the includes, includesfile, excludes, excludesfile and defaultexcludes attributes. With the includes or includesfile attribute you specify the files you want to have included by using patterns. The exclude or excludesfile attribute is used to specify the files you want to have excluded. This is also done with patterns. And finally with the defaultexcludes attribute, you can specify whether you want to use default exclusions or not. See the section on directory based tasks, on how the inclusion/exclusion of files works, and how to write patterns.

This task forms an implicit FileSet and supports all attributes of <fileset> (dir becomes basedir) as well as the nested <include>, <exclude> and <patternset> elements.

You can also use nested file sets for more flexibility, and specify multiple ones to merge together different trees of files into one JAR. The extended fileset and groupfileset child elements from the zip task are also available in the jar task. See the Zip task for more details and examples.

If the manifest is omitted, a simple one will be supplied by Ant.

The update parameter controls what happens if the JAR file already exists. When set to yes, the JAR file is updated with the files specified. When set to no (the default) the JAR file is overwritten. An example use of this is provided in the Zip task documentation. Please note that ZIP files store file modification times with a granularity of two seconds. If a file is less than two seconds newer than the entry in the archive, Ant will not consider it newer.

(The Jar task is a shortcut for specifying the manifest file of a JAR file. The same thing can be accomplished by using the fullpath attribute of a zipfileset in a Zip task. The one difference is that if the manifest attribute is not specified, the Jar task will include an empty one for you.)

Manifests are processed by the Jar task according to the Jar file specification. Note in particular that this may result in manifest lines greater than 72 bytes being wrapped and continued on the next line.

Parameters

Nested elements

metainf

The nested metainf element specifies a FileSet. All files included in this fileset will end up in the META-INF directory of the jar file. If this fileset includes a file named MANIFEST.MF, the file is ignored and you will get a warning.

manifest

The manifest nested element allows the manifest for the Jar file to be provided inline in the build file rather than in an external file. This element is identical to the manifest task, but the file and mode attributes must be omitted.

If both an inline manifest and an external file are both specified, the manifests are merged.

When using inline manifests, the Jar task will check whether the manifest contents have changed (i.e. the manifest as specified is different in any way from the manifest that exists in the Jar, if it exists. If the manifest values have changed the jar will be updated or rebuilt, as appropriate.

Examples

  <jar destfile="${dist}/lib/app.jar" basedir="${build}/classes"/>

jars all files in the ${build}/classes directory into a file called app.jar in the ${dist}/lib directory.

  <jar destfile="${dist}/lib/app.jar"
       basedir="${build}/classes"
       excludes="**/Test.class"
  />

jars all files in the ${build}/classes directory into a file called app.jar in the ${dist}/lib directory. Files with the name Test.class are excluded.

  <jar destfile="${dist}/lib/app.jar"
       basedir="${build}/classes"
       includes="mypackage/test/**"
       excludes="**/Test.class"
  />

jars all files in the ${build}/classes directory into a file called app.jar in the ${dist}/lib directory. Only files under the directory mypackage/test are used, and files with the name Test.class are excluded.

  <jar destfile="${dist}/lib/app.jar">
    <fileset dir="${build}/classes"
             excludes="**/Test.class"
    />
    <fileset dir="${src}/resources"/>
  </jar>

jars all files in the ${build}/classes directory and also in the ${src}/resources directory together into a file called app.jar in the ${dist}/lib directory. Files with the name Test.class are excluded. If there are files such as ${build}/classes/mypackage/MyClass.class and ${src}/resources/mypackage/image.gif, they will appear in the same directory in the JAR (and thus be considered in the same package by Java).

  <jar destfile="test.jar" basedir=".">
    <include name="build"/>
    <manifest>
      <attribute name="Built-By" value="${user.name}"/>
      <section name="common/class1.class">
        <attribute name="Sealed" value="false"/>
      </section>
    </manifest>
  </jar>

This is an example of an inline manifest specification. Note that the Built-By attribute will take the value of the Ant property ${user.name}. The manifest produced by the above would look like this:

Manifest-Version: 1.0
Built-By: conor
Created-By: Apache Ant 1.5alpha

Name: common/class1.class
Sealed: false

Copyright © 2000-2004 The Apache Software Foundation. All rights Reserved.