A simple demo for using wait() and notify() method in java to sync thread

demo_wait_and_notify.java

public class Program {
	static Object lock = new Object();

	static class A implements Runnable {

		@Override
		public void run() {
			synchronized (lock) {
				System.out.println("I'm running in thread A");
				System.out.println("Call wait() in thread A");
				try {
					lock.wait();
				} catch (InterruptedException e) {
				}
				System.out.println("Notify called from another thread!");
				System.out.println("Thread A is running...");
			}
		}

	}

	static class B implements Runnable {

		@Override
		public void run() {
			System.out.println("I'm running in thread B");
			System.out.println("Sleep 2s then notify for thread A...");
			try {
				Thread.sleep(2000);
			} catch (InterruptedException e) {
			}
			synchronized (lock) {
				lock.notify();
			}
			System.out.println("Called notify");
		}

	}

	public static void main(String[] args) {
		new Thread(new A()).start();
		new Thread(new B()).start();
	}
}