lock on Classname.class?

[Sandeep Chhabra]

Hi,
I am not able to understand the following code and especially the line marked as 1

class TestThread extends Thread
{
public void restart()
{
startMe();
}
public static void startMe()
{
synchronized(TestThread.class)//1
{
TestThread.class.notifyAll();
System.out.println("Trying to Notify");
}
}
public void run()
{
try
{
synchronized(this)
{
wait();
System.out.println("Notified");
}
}
catch(InterruptedException e)
{}
}
public static void main(String[]a)
{
TestThread t1=new TestThread();
t1.start();
t1.restart();
}
}

I want to know that the statement marked as 1 is locking on what object.
Besides the output of this is:
Trying to notify
and then it waits forever.

Why is this happening?

Thanks for your help.

[Steve Morrow]

I want to know that the statement marked as 1 is locking on what object.

It is locking on the instance of the Class class referred to by the TestThread.class literal. Similar to the concept of the string literal "foo" referring to a String object, the class literal refers to a Class object. Section 15.8.2 of the Java� Language Specification discusses class literal expressions.

Hope this helps.