import java.util.*;
class Multithreading {
int val;
boolean value = false;
synchronized int get() {
if(!value)
try {
wait();
} catch(Exception e) {
System.out.println(e);
}
System.out.println("Get: " + val);
value = false;
notify();
return val;
}
synchronized void put(int val) {
if(value)
try {
wait();
}catch(Exception e) {
System.out.println(e);
}
this.val = val;
value = true;
System.out.println("Put: " + val);
notify();
}
}
class Producer implements Runnable {
Multithreading th;
Producer(Multithreading th) {
this.th = th;
new Thread(this, "Producer").start();
}
public void run() {
int i = 0;
while(i<=50) {
th.put(i++);
}
}
}

class Consumer implements Runnable {
Multithreading th;
Consumer(Multithreading th) {
this.th = th;
new Thread(this, "Consumer").start();
}
public void run() {
while(true) {
th.get();
}
}
}
class ProducerConsumer {
public static void main(String args[]) {
Multithreading th = new Multithreading();
new Producer(th);
new Consumer(th);
}
}

In the above code, one thread is producing data and another is consuming it. The two threads "Producer" and "Consumer" share the synchronized methods of the class "Multithreading". At time of program execution, the "put( )" method is invoked through the "Producer" class which increments the variable "num" by 1. After producing 1 by the producer, the method "get( )" is invoked by through the "Consumer" class which retrieves the produced number and returns it to the output.