jh_classpath [debhelper options] [-ppackage] [--classpath=cp] [jar [...]]
It has two modes of operations. By default, it will read debian/package.classpath or debian/classpath and set the classpath of all jar files listed in that file. In this mode, jh_classpath does not accept any non-option arguments.
Alternatively, you can pass jh_classpath a list of jar files to update. It will process each of those and set the classpath of them to that value set by --classpath if passed. If --classpath is omitted the environment variable CLASSPATH will be used instead (rewriting its contents as necessary). In this mode, jh_classpath will not read debian/package.classpath nor debian/classpath.
The file consists of 0 or more lines with the following:
jarfile classpath-file1 [... classpath-file2]
Note that each file in the classpath is space-separated in this configuration file.
Beyond the above, jh_classpath also accepts the shared debhelper options documented in debhelper(7).
This program is a part of javahelper and uses debhelper as backend. There are also tutorials in /usr/share/doc/javahelper.