Implementation of Producer Consumer problem studied the use of synchronize, notify(), notifyAll(), sleep() and wait() methods.

ProducerConsumer.java

import java.util.Iterator;
import java.util.LinkedList;
import java.util.Queue;
 
class MessageQueue {

  Queue<String> queue = new LinkedList<String>();
  private int maxSize = 10;
 
  synchronized void removeElement() throws InterruptedException {
    while (true) {
      while (queue.isEmpty()) {
        wait(); // when the queue is empty, the consumer must stop the
        // consumption.
      }
      queue.remove();
      System.out.print("After Consumption Queue::::::[");
      Iterator<String> it = queue.iterator();
      while (it.hasNext())
        System.out.print(it.next() + ",");
        System.out.print("]");
        System.out.println();
        notifyAll();
    }
  }
 
  synchronized void addElement(String message) throws InterruptedException {
    while (queue.size() == maxSize) {
      wait(); // when the queue is full, the producer must stop the
      // production.
    }
    queue.add(message);
    System.out.print("After Insert Queue::::::[");
    Iterator<String> it = queue.iterator();
    while (it.hasNext())
      System.out.print(it.next() + ",");
      System.out.print("]");
      System.out.println();
      notify();
  }
}
 
class Producer implements Runnable {
  MessageQueue messageQueue;
  String emailMessageContent;
 
  public Producer(String message, MessageQueue messageQueue) {
    emailMessageContent = message;
    this.messageQueue = messageQueue;
  }
 
  public void run() {
    try {
      messageQueue.addElement(emailMessageContent);
    } catch (InterruptedException e1) {
      e1.printStackTrace();
    }
  }
}
 
class Consumer implements Runnable {
  
  MessageQueue messageQueue;
  
  public Consumer(MessageQueue messageQueue) {
    this.messageQueue = messageQueue;
  }
 
  public void run() {
    try {
      messageQueue.removeElement();
    } catch (InterruptedException e) {
      e.printStackTrace();
    }
    }
  }
 
  public class ProducerConsumer {
    public static void main(String[] args) throws InterruptedException {
      MessageQueue messageQueue = new MessageQueue();
      new Thread(new Consumer(messageQueue)).start();
      for (int i = 0; i < 10; ++i) {
      new Thread(new Producer("" + i, messageQueue)).start();
    }
  }
}