concurrency

package test;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

public class ThreadTest {

    public static void main(String[] args) {
        Share commonObj = new Share();
        Thread[] threads = ModuloIncrement.createThreads(commonObj, 2);

        for (Thread t : threads) {
            t.start();
        }

        for (Thread t : threads) {
            try {
                t.join();
            } catch (InterruptedException ex) {
                Logger.getLogger(ThreadTest.class.getName()).log(Level.SEVERE, null, ex);
            }
        }

        System.out.println("Exit Main Thread");

    }
}

class ModuloIncrement implements Runnable {

    private final Share share;
    private final int base, modulo;

    private ModuloIncrement(Share share, int base, int modulo) {
        this.share = share;
        this.base = base;
        this.modulo = modulo;
    }

    public void run() {
        print("start");

        synchronized (share) {
            while (true) {
                if (share.number >= share.max) {
                    break;
                }
                if (share.number % base == modulo) {
                    print(share.number + "");
                    share.notifyAll();
                    share.number++;
                } else {
                    try {
                        share.wait();
                    } catch (InterruptedException ex) {
                        Logger.getLogger(ModuloIncrement.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
            }
        }

        print("end");
    }

    private void print(String msg) {
        System.out.println(this + ": " + msg);
    }

    public static Thread[] createThreads(Share share, int count) {
        Thread[] mit = new Thread[count];
        for (int i = 0; i < count; i++) {
            mit[i] = new Thread(new ModuloIncrement(share, count, i));
        }
        List<Thread> l = Arrays.asList(mit);
        Collections.shuffle(l);
        return l.toArray(mit);
    }

    @Override
    public String toString() {
        return "ModuloIncrement{" + "share=" + share + ", base=" + base + ", modulo=" + modulo + '}';
    }
}

class Share {

    volatile int number = 1;
    final int max = 50;

    @Override
    public String toString() {
        return "Share{" + "number=" + number + ", max=" + max + '}';
    }
}