Java Daemon Thread

package com.JavaInterview.Programs;

/**

 * *You can make any java thread as daemon thread. Daemon threads acts like service providers

 *  for other threads running in the same process.Daemon threads will be terminated by the 

 *  JVM when there are none of the other threads running, it includes main thread of execution 

 *  as well.

 * @author:http://javainterviewprograms.blogspot.in/

 * 

 */

public class DaemonThread extends Thread{

    

   public DaemonThread(){

       setDaemon(true);

   }

   public void run(){

       System.out.println("Is this thread Daemon? - "+isDaemon());

   }

   public static void main(String a[]){

       DaemonThread dt = new DaemonThread();

       // you can set daemon constrain here also

       // it is like dt.setDeamon(true)

       dt.start();

   }

}

Output:

Is this thread Daemon? - true

Java Thread :Extending Thread Class

package com.JavaInterview.Programs;

/* 

** A thread can be created in java by extending Thread class, where you must override run() method.

* Call start() method to start executing the thread object.

* @author:http://javainterviewprograms.blogspot.in/

* 

*/

public class ThreadExtendJIP extends Thread {

  

    public ThreadExtendJIP(String name) {

        super(name);

    }

    @Override

    public void run() {

        System.out.println("MyThread - START "+Thread.currentThread().getName());

        try {

            Thread.sleep(1000);

            //Get database connection, delete unused data from DB

            doDBProcessing();

        } catch (InterruptedException e) {

            e.printStackTrace();

        }

        System.out.println("MyThread - END "+Thread.currentThread().getName());

    }

    private void doDBProcessing() throws InterruptedException {

        Thread.sleep(5000);

    }

     

}

 class ThreadRunExample {

  

    public static void main(String[] args){

        Thread t1 = new ThreadExtendJIP("t1");

        Thread t2 = new ThreadExtendJIP("t2");

        System.out.println("Starting MyThreads");

        t1.start();

        t2.start();

        System.out.println("MyThreads has been started");

         

    }

}

Output:

Starting MyThreads

MyThreads has been started

MyThread - START t1

MyThread - START t2

MyThread - END t2

MyThread - END t1

Java Thread :Implementing Runnable Interface

package com.JavaInterview.Programs;

/**

 * *A Thread can be created by extending Thread class also. But Java allows only one class to extend,

 *   it wont allow multiple inheritance. So it is always better to create a thread by implementing 

 *  Runnable interface. Java allows you to implement multiple interfaces at a time.

 * * By implementing Runnable interface, you need to provide implementation for run() method.

 * *To run this implementation class, create a Thread object, pass Runnable implementation class        *   object to its constructor. Call start() method on thread class to start executing run() method.

 * 

 * @author:http://javainterviewprograms.blogspot.in/

 * 

 */

public class RunnableThreadJIP implements Runnable{

    public static int myCount = 0;

    public RunnableThreadJIP(){

         

    }

    public void run() {

        while(RunnableThreadJIP.myCount <= 10){

            try{

                System.out.println("Expl Thread: "+(++RunnableThreadJIP.myCount));

                Thread.sleep(100);

            } catch (InterruptedException ex) {

                System.out.println("Exception in thread: "+ex.getMessage());

            }

        }

    }

}

class MyThread {

    public static void main(String a[]){

        System.out.println("Starting Main Thread...");

        RunnableThreadJIP rt = new RunnableThreadJIP();

        Thread t = new Thread(rt);

        t.start();

        while(RunnableThreadJIP.myCount <= 10){

            try{

                System.out.println("Main Thread: "+(++RunnableThreadJIP.myCount));

                Thread.sleep(100);

            } catch (InterruptedException ex){

                System.out.println("Exception in main thread: "+ex.getMessage());

            }

        }

        System.out.println("End of Main Thread...");

    }

}

Output:

Starting Main Thread...

Main Thread: 1

Expl Thread: 2

Main Thread: 3

Expl Thread: 4

Main Thread: 5

Expl Thread: 6

Main Thread: 7

Expl Thread: 8

Main Thread: 9

Expl Thread: 10

Main Thread: 11

End of Main Thread...