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Building Using Ant
Creating a One-JAR file requires no special tools: the Java jar command is
all that is necessary. However, the hierarchical nature of One-JAR files can prove complex to
construct, even when automated within an Ant script.
There is a simple way: an Ant task called <one-jar> has been created.
This task extends the Ant <jar> task, so it should be immediately familiar
and usable to those experienced with Ant. To construct a One-JAR file using this task,
simply include the XML fragment that defines the taskdef, and invoke the target.
An outline of the <one-jar> task is shown below:
<one-jar destfile=... manifest=...>
<manifest>
Attributes for the manifest of the One-JAR. Use this instead of
specifying a "manifest" attribute above
<attribute name="attr" value="value">
... etc.
</manifest>
<main [jar="main.jar"]>
<filesets> which comprise the class-files of the main application.
Do not put JAR files in here; rather use the "jar" attribute if you already have a
pre-canned main program.
</main>
<lib>
<filesets> containing Jar-files which support the main application.
</lib>
<binlib>
<filesets> containing native libraries. Native libraries are expanded into a
temporary directory at runtime: these files are deleted on exit.
</binlib>
<wrap>
<filesets> containing class-loader wrappers. These check classloaders
that are loaded from the supporting Jar files to make sure they are compatible
with the One-JAR classloader. This is a complex subject, contact one-jar-support for
more information and consulting services if you need to wrap a classloader.
You will know you need this if your application does not load classes when
you expect it should, from JAR files inside the <lib> directory.
</wrap>
<fileset>
Any other stuff you want in the top-level One-JAR file. Remember though, any
.class files you put in here will not be able to "see into" JAR files loaded
from /main and /lib because their classloader will be the top-level Java
Application Loader, which does not understand One-JAR files (this is how One-JAR
came about in the first place). Contact one-jar support if you find
yourself having problems with this kind of issue.
</fileset>
</one-jar>
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