throw exception question

[reubin haz]

In K & B book, when it talks about Exception class, there are 2 examples that have compiler error, but it did not say what the problem is:

 
class MyException extends Exception { }
 
class TestEx {
   void doStuff() {
     throw new MyException();  // Throw a checked exception
   }
}
  

 
class MyException extends Exception { 
void someMethod () {
    doStuff();
}
void doStuff() throws MyException {
   try {
      throw new MyException();
    }
   catch(MyException me) { 
      throw me;
    }
}
  

Can someone help me which line in these two examples has the problem, and how to correct them?

Thanks

[Joe Sondow]

Originally posted by reubin nibuer:

class MyException extends Exception { }
 
class TestEx {
   void doStuff() {
     throw new MyException();  // Throw a checked exception
   }
}

The doStuff() method throws a checked exception, but does not declare the exception in a throws clause. It would compile if you changed the method declaration to:
void doStuff() throws MyException {

class MyException extends Exception { 
void someMethod () {
    doStuff();
}
void doStuff() throws MyException {
   try {
      throw new MyException();
    }
   catch(MyException me) { 
      throw me;
    }
}

The method someMethod() invokes doStuff(), which throws a checked exception. Therefore, one of two changes could be made to the code to allow it to compile.
(1) The declaration of someMethod() could be changed to
void someMethod () throws MyException {
OR
(2) Inside someMethod(), the call to doStuff() could be put inside a try-catch block that would handle the MyException.

[reubin haz]

I got it, thank you very much