Reader Level:
ARTICLE

Threading in Java

Posted by Abhishek Dubey Articles | Java February 13, 2012
In this article you can learn the basic steps of creating a thread; this article provides two ways for creating your own thread in Java.
  • 0
  • 0
  • 4772

Introduction

Until now, the programs we have discussed so far were sequential ones, i.e. each of the them has a beginning, an execution sequence, and an end. While the program is being executed, at any point of time, there is a single line of execution. One thing that you must note that a thread in itself is not a program, as it cannot run on its own. However it can be embedded with any other program.
A thread is a single sequential flow of control within a program. There are many definition of thread some of the A thread is a lightweight process, a thread is a basic processing unit to which an operating system allocates processor time and more than one thread can be executing code inside a process.

States of thread- A thread has one of the following States.
 
New-This is a state when a thread is not started. But the thread is created.

1-Runnable- This is the execution state of the thread.

2-Blocked- This is the state when a thread is waiting for a lock to access an object.

3-Waiting-In this state a thread is waiting indefinitely for another thread to perform an action.

4-Timed__Waiting. A state in which a thread is waiting for up to a specified period of time for another thread to perform an action.

5-Not Runnable- after Runnable states these three states are assumed to be in a not Runnable state. These three states are waiting, Timed_waiting and Terminated.

6-Terminated- In this state the thread is dead.

Life Cycle of  a thread

thread2.jpg

 

Crating a thread- There are two ways for creating a thread.

Method-1 : By extend the Thread class of java.lang package.
Syntax...........

class MyThread extends Thread
{
-----------------;
-----------------;
}

Override the run( ) Method-
The run( ) method has to be Overridden by writing codes required for the thread. The thread behaves as per this code segment.

public void run()
{
----------------;
----------------;
}

Example- In this Example we are going to create a thread with the help of the extends Thread class.

class MyThread extends Thread
  {
    int i;
    MyThread(int i)
     {
      this.i=i;
     
     }
    public void run() //this method overrid from thread class
     {
     
       while(true)
          {                
         System.out.println("abhishek kumar dubey:"+i++);
         try
          {
            Thread.sleep(1500);   // use for break 1500 mili second
          }
          catch(InterruptedException e)
           {
             System.out.println(e);
           }
                 if (i==15 ) // use for terminate the infinite loop
            {
           System.out.println(Thread.currentThread());
           break;
           }
         
        }
      }
   }
 
 public class TestThread
   {
     public static void main(String []args)
       {
 
         MyThread m1=new MyThread(1);
     
              m1.start();     // for start thread 
 
           System.out.println(Thread.currentThread());
         }
   }

OUTPUT:

thread1.jpg

 
Method :2
By Implements Runnable Interface.

Note- If you make a thread by using Runnable Interface then it must override the run() method.

public MyThread implements Runnable
{
-----------
-----------

public void run()
{
------
------
}

}

Example-

import java.lang.*;
class Runner1 implements Runnable
{
  int i;
    public void run()      //this method overrid from Runnable interface must be,fuctionality as per reqairements 
      {
        i=0;
         while(true)
         {
          System.out.println("Runner_first"+i++);
             if (i==10)
              break;
           }
       }
    }
 
class Runner2 implements Runnable
  {
    int i;
    public void run()
     {
       i=0;
       while(true)
       {
                         
          System.out.println("Runner_second"+i++);
           if (i==10)
            break;
         }
      }
   }
 
 
 public class ThreadDemo
    {
      public static void main(String []args)
       {
       Runner1 r=new Runner1();
 
         Thread t=new Thread(r);  // I M P
 
 /*from here run() method call which is override in Runner class*/  
 
            t.start();           // for start thread 4 execution
             
               
           Runner2 r1=new Runner2();
              Thread t1=new Thread(r1);
 
 /*from here run() method call which is override in Runner class*/  
 
              t1.start();
        
         }
}

OUTPUT:

treadDemocmd.jpg


Resource

First Step to Java's Multithreading

Use of ByteStreams and CharacterStreams in JAVA

COMMENT USING

Trending up