Exception never thrown??

[srikanth reddy]

 class RedException extends Exception {}
class BlueException extends Exception {}
class White {
  void m1() throws RedException {throw new RedException();}
  public static void main (String[] args) {
    White white = new White();
    int a,b,c,d; a = b = c = d = 0;
    try {white.m1(); a++;}
      catch (RedException e) {b++;}
      catch (BlueException e) {c++;}
      finally {d++;}
    System.out.print(a+","+b+","+c+","+d);
}}

it is giving me the compiler error stating that the Blue exception is never thrown in the try block ....is it mandatory that what exceptions my try block going to throw ..those only be caught ..i experienced the same problem when i was throwing IOException in an empty try block...
please clarify

[Sravan Kumar]

1. All checked exceptions that are thrown from a try block must be handled with a corresponding catch block or must be declared to be thrown.

2. catch blocks must exist only for those checked exceptions that are thrown from the corresponding try block. This means you cannot have a catch block that handles a checked exception that is never thrown from the body of a try block.

[A Kumar]

Hi,

This means you cannot have a catch block that handles a checked exception that is never thrown from the body of a try block.

Because that would amount to unreachable code..