How to fire Java method using bash

Question

Suppose I launch a Java application:

java -cp whatever.jar com.example.Start

Process launches ok and keeps running with PID 1314.

Now I would like the system to fire a method by users request.
How can I use bash to signal the running PID and have it fire a method?

Answer 1

My thought is to have bash echo data to the Java processes via a named pipe, which I'm pretty sure Java has support for.