Threads and Locks - Object.wait() method

ThreadWaitDemo.java

package com.codinko.example;

/**
 * 
 * Feel free to play around with this code to try various topics covered under Threads & Locks:
 * 
 *  Theory reference: https://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html
 *
 */
public class ThreadWaitDemo {
	
	Employee employeeObj1 = new Employee();
	
	Runnable r1 = new Runnable() {
		@Override
		public void run() {
			System.out.println(String.format("running thread : %s", Thread.currentThread().getName()));

			/*
			 * try { employeeObj1.wait(); // I expect // "Exception in thread "Thread-0
			 * " java.lang.IllegalMonitorStateException" // and u'll get it :)
			 *//**
			 * Let thread t be the thread executing the wait method on object
			 * m, and let n be the number of lock actions by t on m that have
			 * not been matched by unlock actions. One of the following actions
			 * occurs:
			 * 
			 * If n is zero (i.e., thread t does not already possess the lock
			 * for target m), then an IllegalMonitorStateException is thrown.
			 * 
			 */
			/*
			 * } catch (InterruptedException e) { e.printStackTrace(); }
			 */
			employeeObj1.changeMyName("Harley");
		}
	};
	
	Runnable r2 = new Runnable() {
		@Override
		public void run() {
			System.out.println(String.format("running thread : %s", Thread.currentThread().getName()));
			//employeeObj1.notify(); //Exception in thread "Thread-1" java.lang.IllegalMonitorStateException
			employeeObj1.changeMyName("Harley");
		}
	};

	public static void main(String[] args) {
		new ThreadWaitDemo().startThread();
	}

	public void startThread() {
		new Thread(r1).start();
		new Thread(r2).start();
	}

	class Employee {
		String name;
		public String getName() {
			return name;
		}
		public void setName(String name) {
			this.name = name;
		}
		public synchronized void changeMyName(String newName) {
			try {
				employeeObj1.wait(5000);
				//employeeObj1.wait(); // wait for ever if wait() or wait for milliseconds if wait(long ms) . this time there is no
							// java.lang.IllegalMonitorStateException as thread
							// has the lock on employeeObj1's monitor
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			System.out.println(String.format("Changing the name to : %s by thread : %s ", newName, Thread.currentThread().getName()));
			this.name = newName;
			//employeeObj1.notify();
		}
	}
}


//OUTPUT 
/*

running thread : Thread-0
Exception in thread "Thread-1" java.lang.IllegalMonitorStateException
running thread : Thread-1
	at java.lang.Object.notify(Native Method)
	at com.example.compare.ThreadWaitDemo$2.run(ThreadWaitDemo.java:37)
	at java.lang.Thread.run(Thread.java:662)
Changing the name to : Harley by thread : Thread-0 

*/

/*

running thread : Thread-0
running thread : Thread-1
Changing the name to : Harley by thread : Thread-0 
Changing the name to : Harley by thread : Thread-1 

 */