Question

I have often come across this snippet :

{

 SwingUtilities.invokeLater(new Runnable()
   {
   public void run() {
     new tester();  // class name
   }
 });

}

I know why are we using this,but cannot understand how it is going.I mean i dont understand this snippet.

(We are initializing object under run method,,,why?? )

Please explain this

Answer 1

With that bit of code you’re creating a Inner Class that implements Runnable, that instance will be enqueued in the AWT processing task dispatcher for later processing in a thread. Quoting the documentation, invokeLater …

Causes doRun.run() to be executed
asynchronously on the AWT event
dispatching thread. This will happen
after all pending AWT events have been
processed.

So at some point, the AWT dispatcher will decide to run that instance of Runable in a thread. That will provoke the execution of the method run and therefore the execution of the statement new tester();, which simply create an instance of the class tester.

To your specific question …

We are initializing object under run
method,,,why??

It really doesn’t seem right to just create a class in the run method, unless the constructor is doing lots of things which is actually a bad practice.

It’be much more intuitive to do something like :

SwingUtilities.invokeLater(new Runnable()
   {
   public void run() {
     Tester t = new Tester();
     t.doSomeStuff();
   }
 });