Creating a Java Thread by extending Thread Class

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Creating a Java Thread by extending Thread Class

Creating a Java Thread by extending Thread Class

A thread can be created in Java programs in two ways – by extending Thread class and by implementingRunnable interface. In case, where the class extends a Tread class, it must override run() method of the Thread class. The program may override the other methods also. If the program uses Runnable interface, it needs to implement only run() method.

The first way to create a thread is to create a subclass of the Thread class. This class must override the run( ) method and it may also override the other methods defined with the class. Then the class that needs the thread can create an object of the class that extends thread class. Following example shows the concept of threads clearly.

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class MyThread extends Thread 
{ 
    MyThread ( ) 
    { 
        ..... 
        ..... 
    }         
 
public void run ( ) //must override this method    
 
    { 
        ..... 
        ..... 
    }     
 
        ..... 
} 
 
public class MainClass 
{     
 
  public static void main()      
 
{         
 
  MyThread t = new MyThread (); 
   ....... 
   t.start () ; 
   ....... 
   } 
}

Let us now create a sample Fibonacci Program using threads that generates Fibonacci series. This program creates the thread by extending thread class:

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class PrintFibo 
{ 
    public static void main(String args[]) 
  { 
    JavaFib t = new JavaFib (20); 
    t.start ( ); 
  } 
} 
 
class JavaFib extends Thread 
{ 
          //number of elements to generate in a series 
            private int num; 
 
            JavaFib (int itr) 
              { 
                num=itr; 
              }        
 
            public void run() 
            { 
                long[] series = new long[num]; 
 
            //create first 2 series elements 
               series[0] = 0; 
               series[1] = 1; 
 
            //create the Fibonacci series and store it in an array 
                for(int i=2; i < num; i++) 
                { 
                  series[i] = series[i-1] + series[i-2]; 
                } 
 
               //print the Fibonacci series numbers 
 
               System.out.println("Fibonacci Series upto " + num); 
               for(int i=0; i< num; i++) 
               { 
                System.out.print(series[i] + " "); 
               } 
            } 
}

OUTPUT

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Output of the Fibonacci Series Java Example would be 
 
Fibonacci Series upto 20 
 
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181

To crate threads, create a new class that extends the Thread class, and instantiate that class. The extending class must override the run() method and call start() method to begin execution of the thread.

Categories: JAVA, JSP, threadpool, WEB SERVER

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Creating a Java Thread by extending Thread Class

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