java projects in which inheritence , multithreading and interface concept is used code example

Example: multithreading in java simple example

class MultithreadingDemo extends Thread{  
  public void run(){  
    System.out.println("My thread is in running state.");  
  }   
  public static void main(String args[]){  
     MultithreadingDemo obj=new MultithreadingDemo();   
     obj.start();  
  }  
}