Creating multiple threads by extending thread class

Question

I want to know how multiple threads can be created by "extending the Thread class". I know how it is done using "Runnable". Please tell me how it can be done by "extending Thread class".

Why dont you show us what you have tried and then we can help you out. — David says Reinstate Monica, Oct 02 '13 at 05:45
I'm a beginner to java. I don't know how its done. I'm having problems getting started — Aadithya, Oct 02 '13 at 05:46
Here you go : http://docs.oracle.com/javase/tutorial/essential/concurrency/runthread.html — Juned Ahsan, Oct 02 '13 at 05:49
example on stackoverflow: http://stackoverflow.com/a/2531984/1554314 — Taky, Oct 02 '13 at 05:51
You don't want to do it by extending Thread. Runnable is better. http://stackoverflow.com/questions/541487/implements-runnable-vs-extends-thread?rq=1 — Thilo, Oct 02 '13 at 05:52
If you do some homework and then ask. It will be more useful for you and easier for people to explain. — Lokesh, Oct 02 '13 at 05:53

score 8 · Accepted Answer · answered Oct 02 '13 at 06:00

Main Method

public class ThreadDemo 
{   

  public static void main(String args[])    
  {         

    //Creating an object of the first thread        
    FirstThread   firstThread = new FirstThread();              

    //Creating an object of the Second thread       
    SecondThread   secondThread = new SecondThread();               

    //Starting the first thread         
    firstThread.start();                

    //Starting the second thread        
    secondThread.start();   
  } 
}

This class is made as a thread by extending "Thread" class.

public class FirstThread extends Thread 
{ 
  //This method will be executed when this thread is executed 
  public void run() 
  { 

    //Looping from 1 to 10 to display numbers from 1 to 10 
     for (int i=1; i<=10; i++) 
     { 
        //Displaying the numbers from this thread 
        System.out.println( "Messag from First Thread : " +i); 

        /*taking a delay of one second before displaying next number 
        * 
        * "Thread.sleep(1000);" - when this  statement is executed, 
        * this thread will sleep for 1000  milliseconds (1 second) 
        * before executing the next statement. 
        * 
        * Since  we are making this thread to sleep for one second, 
        * we need to handle  "InterruptedException". Our thread 
        * may throw this exception if it is  interrupted while it 
        * is sleeping. 
        * 
        */
        try
        { 
           Thread.sleep(1000); 
        } 
        catch (InterruptedException  interruptedException) 
        { 
          /*Interrupted exception will be thrown when a sleeping or  waiting 
          * thread is interrupted. 
          */
          System.out.println(  "First Thread is interrupted when it is  sleeping" +interruptedException); 
        } 
      } 
   }

This class is made as a thread by extending "Thread" class.

public class SecondThread extends Thread 
{   

  //This method will be executed when this thread is executed   
  public void run()     
  {             
    //Looping from 1 to 10 to display numbers from 1 to 10      
    for (int i=1; i<=10; i++)        
    {           
       System.out.println( "Messag from Second Thread : " +i);                      
       /*taking a delay of one second before displaying next number
       * "Thread.sleep(1000);" - when this statement is executed,
       * this thread will sleep for 1000 milliseconds (1 second) 
       * before executing the next statement.             
       *              
       * Since we are making this thread to sleep for one second,
       * we need to handle "InterruptedException". Our thread
       * may throw this exception if it is interrupted while it 
       * is sleeping.             
       */          
       try         
       {                
          Thread.sleep (1000);          
       }            
       catch (InterruptedException interruptedException)            
       {                
          /*Interrupted exception will be thrown when a sleeping or waiting
           *thread is interrupted.               
           */              
           System.out.println( "Second Thread is interrupted when it is sleeping" +interruptedException);           
       }        
    }   
  }
}

Please check Reference # Threading using Extend for complete detail, For quick reading i m posting code from above mentioned reference

Creating multiple threads by extending thread class

1 Answers1