Multithreading error program

 1:-

class Demo  extends Thread

{

 public void run()

{

System.out.println( "thread task");

}

public static void main (String []args)

{

Demo t= new Demo();

t.start();

t.start();//isme error aya isliya ki start method 2 bar create kar diya hai isliya

ham start method do bar create nahi kar sakte hai

}

}

C:\java>javac Testing.java

C:\java>java Demo

thread task

Exception in thread "main" java.lang.IllegalThreadStateException

        at java.lang.Thread.start(Thread.java:708)

        at Demo.main(Testing.java:12)

C:\java>

2:-

 

class Demo implements Runnable

{

public void run()

{

    System.out.println("MULTITHREADING");

   

}

public void run()

{

    System.out.println("MULTITHREADING"); //ya pe run methoid ko overload nahi kar sakte hai

   

}

public static void main(String args[])

{

Demo t= new Demo ();

Thread  th = new Thread(t);

th.start();

}

}

C:\java>javac Testing.java

Testing.java:10: error: method run() is already defined in class Demo

public void run()

            ^

1 error

3:-