Many times we face scenario where we need to execute two sequential tasks to perform a operation, like Tagging / Stamping serial Coupons , Producing serial Tickets at different Vending Machines. Below code ( generating Odd and Even in sequence) can be used for such requirement.

PS: This is a basic implementation, the same can be done using other Threading concepts.

				
package multithreading;

// print ODD and Even number alternatively

public class SquenceGeneratorTasks {

	public static boolean oddPrinted = false;

	public static void main(String[] args) {
		 Object lock =new Object();
		Thread oddThread = new Thread(new Runnable() {

			@Override
			public void run() {
				int i = 1;
				while (i <= 20) {

					synchronized (lock) {
						if (!oddPrinted) { // make sure printing starting with Odd number and each Odd is followed with a Even number
							System.out.println(i);
							i = i + 2;
							oddPrinted = true;
							lock.notify();
							try {
								lock.wait();
							} catch (InterruptedException e) {
								// TODO Auto-generated catch block
								e.printStackTrace();
							}
						}
					}

				}
			}
		});

		
		Thread evenThread = new Thread(new Runnable() {

			@Override
			public void run() {
				
				System.out.println(" Though you have delayed Odd thread but printing gonna start with Odd number only !!");
				
				int i = 2;
				while (i <= 20) {
					synchronized (lock) {
						if (oddPrinted) {
							System.out.println(i);
							i = i + 2;
							oddPrinted = false;
							lock.notify();
							try {
								lock.wait();
							} catch (InterruptedException e) {
								// TODO Auto-generated catch block
								e.printStackTrace();
							}
						}
					}
				}
			}
		});

		evenThread.start();
		
		// even if We apply some delay to Odd thread printing will start with ODD number only and 
		// Sequence of Odd-Even-Odd maintained
		try {
			Thread.sleep(2000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		oddThread.start();

	}

}						
/*
Though you have delayed Odd thread but printing gonna start with Odd number only !!
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20 */

You can download the same code from : https://github.com/SkilledMinds/easyNuts/tree/master/code-25-09-2015