Implementing a tread in Java

How to create thread

There are two ways to create a thread:

1. By extending Thread class
2. By implementing Runnable interface.

Thread class:

Thread class provide constructors and methods to create and perform operations on a thread.Thread class extends Object class and implements Runnable interface.

Runnable interface:

The Runnable interface should be implemented by any class whose instances are intended to be executed by a thread. Runnable interface have only one method named run().

public void run(): is used to perform action for a thread.

Starting a thread:

start() method of Thread class is used to start a newly created thread. It performs following tasks: A new thread starts(with new callstack). The thread moves from New state to the Runnable state. When the thread gets a chance to execute, its target run() method will run.

1) Java Thread Example by extending Thread class

          class Multi extends Thread
          { 
                   public void run()
                   { 
                            System.out.println("thread is running..."); 
                   } 
                   public static void main(String args[])
                   {  
                            Multi t1=new Multi(); 
                            t1.start(); 
                   } 
          }
  

Output:thread is running...

2) Java Thread Example by implementing Runnable interface

           class Multi3 implements Runnable
          { 
                 public void run()
                 { 
                          System.out.println("thread is running..."); 
                  }   
                 public static void main(String args[])
                 {   
                          Multi3 m1=new Multi3();   
                          Thread t1 =new Thread(m1);   
                           t1.start(); 
                 }   
          }  

Output:thread is running...

If you are not extending the Thread class,your class object would not be treated as a thread object.So you need to explicitely create Thread class object.We are passing the object of your class that implements Runnable so that your class run() method may execute.