Dan chisholm - Exceptions

[P Hunjan]

Hi,

This is a question from Dan chisholm question set.
The answer is Compile time error which I could not understand.

Why can't an exception be caught if its not thrown for sure ?
I was guessing that it may be because its a checked exception & we have'nt used 'throws' clause to specify that it might be thrown.

  
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);
}}

Thanks

[Mark Spritzler]

Maybe it is easier to see the compile time error that gets displayed.

exception BlueException is never thrown in body of corresponding try statement.

Mark

[Barry Gaunt]

As Mark says, please specify the compile error: We do not always have time to compile your code for you. However, since you are dealing with checked exceptions you should analyse your code to see whether both exceptions could actually be thrown. No BlueExceptions are declared to be thrown by the method m1, for example.
[ August 30, 2005: Message edited by: Barry Gaunt ]