Question

i have some small problem.
I hava some class Processor and Process. Process class have only name and value
Processor must calculate this value and display it. In turn, Processor implement Runnable interface
But i have a trouble. When I set process to my Processor, it begin to calculate value, but i want to start another thread with different value of process, and this value set to first thread too.
Here is code

    package ua.edu.lp.controller;

import java.util.Random;

import ua.edu.lp.controller.processors.FirstProcessor;
import ua.edu.lp.controller.processors.MyBaseProcessor;
import ua.edu.lp.model.MyProcess;
import ua.edu.lp.model.Queue;

public class Computer {

    private Queue<MyProcess> queue;

    public void run() {
        MyBaseProcessor myBaseProcessor = new FirstProcessor();
        generateQueue();

        for (int i = 0; i < queue.getQueue().size(); i++) {
            MyProcess process = queue.get(i);
            myBaseProcessor.setProcess(process);
            Thread thread = new Thread(myBaseProcessor);
             thread.start();
        }
    }

    private void generateQueue() {
        queue = new Queue<MyProcess>();
        for (int i = 0; i < 10; i++) {
            String name = "Process[" + (i + 1) + "]";
            MyProcess myProcess = new MyProcess(name,
                    new Random().nextInt(10) + 1);
            queue.add(myProcess);
            System.out.println(myProcess.getName() + "\t"
                    + myProcess.getValue());
        }
    }
}

BaseProcessor

package ua.edu.lp.controller.processors;

import ua.edu.lp.model.MyProcess;

public abstract class MyBaseProcessor implements Runnable {

    protected MyProcess myProcess;

    @Override
    public void run() {
        synchronized (myProcess) {
            calculateValue();
        }
    }

    protected abstract void calculateValue();

    public synchronized MyProcess getProcess() {
        return myProcess;
    }

    public synchronized void setProcess(MyProcess myProcess) {
        synchronized (myProcess) {
            this.myProcess = myProcess;
        }

    }

}

And FirstProcessor

package ua.edu.lp.controller.processors;

public class FirstProcessor extends MyBaseProcessor {

    @Override
    protected synchronized void calculateValue() {
        System.out.println("First processor is working...");
        int value = this.myProcess.getValue();
        int result = (int) Math.pow(value, 2);
        System.out.println("Pow of " + value + " = " + result);
        System.out.println("First processor is free");
    }

}

All project you can download from http://www.sendspace.com/file/5rlmkx

Answer 1

Make Processor stateless – remove field process and do something like this:

final Processor processor = new Processor();

processor.process(new Process(...));

public void process( final Process process ) {
    new Thread(new Runnable() {
        //do somethig with process
        }).run();
}

NOTE: Processor must do only common task – to run process, and process implement business logic and only process aware of calculations you’ve done.