Casting Throwbale to Exception

[Surendra Kumar]

Hi,

As we all know casting super class onject references to subclass references gives ClassCastException.

But casting Throwbale to Exception doesn't give any exception.

why so? is it exception?

[Keith Lynn]

Can you explain what you tried?

I tried this simple program, and it gives a ClassCastException.

public class Test {
 
   public static void main(String[] args) {
      Throwable t = new Throwable();
 
      Exception e = (Exception)t;
   }
 
}

[ August 23, 2006: Message edited by: Keith Lynn ]

[Surendra Kumar]

public void test() {
try{ 
                       throw new Throwable();
                }
catch( ArithmeticException e1) {}
catch(Throwable e) {
try {
throw (Exception) e;
}
catch (Exception e1) {
System.out.println("catch");
return;
}
finally { System.out.println("finally"); }
}
}

[Keith Lynn]

If you add a print statement in the catch block to see the type of exception it is, you will see that it is a ClassCastException.

So the attempt to cast the Throwable object to an Exception causes the ClassCastException. Since ClassCastException is a subclass of Exception, the catch block will catch it.
[ August 23, 2006: Message edited by: Keith Lynn ]

[Surendra Kumar]

Yes, you're right.
Thanks a lot.