Synchronized Keyword

http://www.try2catch.in

Synchronized is a keyword use for thread concepts. There are chances when two or more threads are trying to access same resource. At this point, program will get stuck or hang. So to come over this situation java has synchronized keyword.

We just need to share those resources to synchronized block.

public class TryCatch {

       public static void main(String args[]) {

              CounterDemo counterDemo = new CounterDemo();

              ThreadDemo thread1 = new ThreadDemo("Thread - 1 ", counterDemo);

              ThreadDemo thread2 = new ThreadDemo("Thread - 2 ", counterDemo);

              thread1.start();

              thread2.start();

              try {

                     thread1.join();

                     thread2.join();

              } catch (Exception e) {

                     System.out.println("Interrupted");

              }

       }

}

class CounterDemo {

       public void counterCount() {

              try {

                     for (int i = 0; i <= 10; i++) {

                           System.out.println("Counter   ---   " + i);

                     }

              } catch (Exception e) {

                     System.out.println("Thread  interrupted.");

              }

       }

}

class ThreadDemo extends Thread {

       private Thread thread;

       private String threadName;

       CounterDemo counterDemo;

       ThreadDemo(String name, CounterDemo counterDemo) {

              threadName = name;

              this.counterDemo = counterDemo;

       }

       public void run() {

              /*

               * Try to run this code with uncomment and comment line 53. You will see

               * the difference

               */

             

              // counterDemo.counterCount();

              synchronized (counterDemo) {

                     counterDemo.counterCount();

              }

              System.out.println("Thread " + threadName + " running...");

       }

       public void start() {

              System.out.println("Starting " + threadName);

              if (thread == null) {

                     thread = new Thread(this, threadName);

                     thread.start();

              }

       }

}