python - How to call java objects and functions from CPython?

Question

I have a python program, which runs on the CPython implementation, and inside it I must call a function defined in a java program. How can I do this?

It would be nice to be able to use some java objects too.

Jython is not an option. I must run the python part in CPython.

Answer 1

Apologies for resurrecting the thread, but I think I have a better answer :-)

You could also use Py4J which has two parts: a library that runs in CPython (or any Python interpreter for that matter) and a library that runs on the Java VM you want to call.

There is an example on the frontpage and lots of documentation, but essentially, you just call Java methods from your python code as if they were python methods:

>>> from py4j.java_gateway import JavaGateway
>>> gateway = JavaGateway()                        # connect to the JVM
>>> java_object = gateway.jvm.mypackage.MyClass()  # invoke constructor
>>> other_object = java_object.doThat()
>>> other_object.doThis(1,'abc')
>>> gateway.jvm.java.lang.System.out.println('Hello World!') # call a static method

The communication is done through sockets instead of JNI.

Disclaimer: I am the author of Py4J