Jlink

Description:

Links entries from sub-builds and libraries.

The jlink task can be used to build jar and zip files, similar to the jar task. However, jlink provides options for controlling the way entries from input files are added to the output file. Specifically, capabilities for merging entries from multiple zip or jar files is available.

If a mergefile is specified directly (eg. at the top level of a mergefiles pathelement) and the mergefile ends in ".zip" or ".jar", entries in the mergefile will be merged into the outfile. A file with any other extension will be added to the output file, even if it is specified in the mergefiles element. Directories specified in either the mergefiles or addfiles element are added to the output file as you would expect: all files in subdirectories are recursively added to the output file with appropriate prefixes in the output file (without merging).

In the case where duplicate entries and/or files are found among the files to be merged or added, jlink merges or adds the first entry and ignores all subsequent entries.

jlink ignores META-INF directories in mergefiles. Users should supply their own manifest information for the output file.

It is possible to refine the set of files that are being jlinked. This can be done with the includes, includesfile, excludes, excludesfile, and defaultexcludes attributes on the addfiles and mergefiles nested elements. 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. The patterns are relative to the base directory.

Parameters:

Attribute	Description	Required
outfile	the path of the output file.	Yes
compress	whether or not the output should be compressed. true, yes, or on result in compressed output. If omitted, output will be uncompressed (inflated).	No
mergefiles	files to be merged into the output, if possible.	At least one of mergefiles or addfiles
addfiles	files to be added to the output.	At least one of mergefiles or addfiles

Examples

The following will merge the entries in mergefoo.jar and mergebar.jar into out.jar. mac.jar and pc.jar will be added as single entries to out.jar.

<jlink compress="false" outfile="out.jar">
   <mergefiles>
     <pathelement path="${build.dir}/mergefoo.jar"/>
     <pathelement path="${build.dir}/mergebar.jar"/>
   </mergefiles>
   <addfiles>
     <pathelement path="${build.dir}/mac.jar"/>
     <pathelement path="${build.dir}/pc.zip"/>
   </addfiles>
</jlink>

Suppose the file foo.jar contains two entries: bar.class and barnone/myClass.zip. Suppose the path for file foo.jar is build/tempbuild/foo.jar. The following example will provide the entry tempbuild/foo.jar in the out.jar.

<jlink compress="false" outfile="out.jar">
   <mergefiles>
     <pathelement path="build/tempbuild"/>
   </mergefiles>
</jlink>

However, the next example would result in two top-level entries in out.jar, namely bar.class and barnone/myClass.zip

<jlink compress="false" outfile="out.jar">
   <mergefiles>
     <pathelement path="build/tempbuild/foo.jar"/>
   </mergefiles>
</jlink>