A Java class or interface can have, at maximum, 65535 number of methods.
The responsible Java class can be freely used in other applications.
Actions are Java classes that execute some business logic or manage new content production.
Memory overhead is a few hundred bytes per Java class.
For example, with a click on a visual artifact one can turn a Java class into a web service.
Consider a Java class which represents a 2 dimensional point.
Jython programs can import and use any Java class.
Each Java class must be loaded by a class loader.
A plugin could implement and return an instance to a Java class.
Below is an example of a typical Java class implementing the interface: