Calling Sleep with and without instance Query

[Mohit G Gupta]

sleep is a static method of thread class

let there be a Thread t

class M{


public static void main(String arg[]){
Thread t=new Thread(new Runnable(){
      public void run(){
      try{
          Thread.sleep(1000);//line 1
         }catch(Exception e)
              {}
   }
   );

t.start();
System.ou.println("hello");
t.sleep(2000);  //line 2
System.ou.println("hello again");

}
}

what does line 1 and line2 do....
Do line 1 causes the Thread t to sleep ?
Do line 2 also does the same thing ?

[Ankit Garg]

Calling a static method on an instance of the class is same as calling it using the class name. So the call to t.sleep(2000) at line 2 is the same as Thread.sleep(2000)...

[Wouter Oet]

The code won't do anything since is doesn't compile because of 3 different reasons.
Then that is fixed it will cause the thread to sleep (execute nothing). Like Ankit said you can invoke static methods through an reference to an instance.
However this is not recommended because when you change the reference type (anyone got a better name for reference type?) you'll invoke a different static method.

[Mohit G Gupta]

Calling a static method on an instance of the class is same as calling it using the class name. So the call to t.sleep(2000) at line 2 is the same as Thread.sleep(2000)...

so t.sleep and Thread.sleep would cause the newly created thread to sleep

[Rohit Ramachandran]

Compile error because you didn't enclose the second sleep in a try catch.

[Ankit Garg]

Mohit, what does the javadocs for sleep method say?? I believe it says

Causes the currently executing thread to sleep

So it basically sleeps the thread which calls it. Period...

[Gari Jain]

t.sleep() is same as Thread.sleep()-will put the thread in current execution to sleep.

don't get confused by code which seems to call sleep on some other thread instance.

Thread anotherThread at=new Thread(--runnable object--);

anotherThread.sleep();

--will put to sleep the current thread in execution only because anotherThread.sleep(); is same as Thread.sleep();

[Mohit G Gupta]

Thread anotherThread at=new Thread(--runnable object--);

anotherThread.sleep();

If the following code is in main method
then,

anotherThread.sleep();
Thread,sleep();

would cause the main Thread to sleep and not the anotherThread
But if same code was in run method of anotherThread,then

anotherThread.sleep();
Thread,sleep();

would cause the anotherThread to sleep and not the main Thread

Am i right ?