Hello Readers , In this blog I am going to discuss about Join() Method and how we can use ?

As we know that Thread execution In Java occurs according to Thread Priority.The Threads having same priority  can be executed randomly. However we can make Thread to wait until one thread complete its execution by the help of Join() method. Join () method is a type of checked exception so it should be surround with try and catch block otherwise it throws InterruptedException.

Lets see through Example :

1. Creating class A

public class A extends Thread{

	public void run()
{
	for(int i=1;i<10;i++)
	{
		System.out.println("calling from A "+i);
	}
}
}

2. Creating class B

public class B extends Thread{

		public void run()
	{
		for(int i=1;i<10;i++)
		{
			System.out.println(" calling from B :  "+i);
		}
	}

}

If We don't use Join() Method , Lets see what's result :

public class Demo {
 public static void main(String args[])
 {
	 A x=new A();
	 B y=new B();
	 x.start();
	 y.start();
 }
}

Output :

 calling from B :  1
calling from A 1
 calling from B :  2
calling from A 2
 calling from B :  3
calling from A 3
 calling from B :  4
calling from A 4
 calling from B :  5
 calling from B :  6
calling from A 5
 calling from B :  7
calling from A 6
 calling from B :  8
calling from A 7
 calling from B :  9
calling from A 8
calling from A 9

Now lets see the Result on using Join() Method :

public class Demo {
 public static void main(String args[])
 {
	 A x=new A();
	 B y=new B();
	 x.start();
	try {
		x.join();
	} catch (InterruptedException e) {
		e.printStackTrace();
	}
	 y.start();
 }
}

Output:

calling from A 1
calling from A 2
calling from A 3
calling from A 4
calling from A 5
calling from A 6
calling from A 7
calling from A 8
calling from A 9
 calling from B :  1
 calling from B :  2
 calling from B :  3
 calling from B :  4
 calling from B :  5
 calling from B :  6
 calling from B :  7
 calling from B :  8
 calling from B :  9