Licensed versions of XBinder include the runtime source code for various Java and Java-like platforms. In your installation's java folder, this source is available as runtime_src.zip. Unzipping this in the java folder will produce a subfolder named build.
java/build.xml is the Apache Ant build script to build the runtimes. The script was tested using Ant 1.8.0.
In the java folder, run ant <target> where target is one of jse_compile.