simple question about overriding

[s.palanivel rajan]

What exception can an overridden method throw in comparison with the method it is overriding?

[pankaj vijay]

The over ridden method can throw same exception as super class method throwing & the subclasses of that exception.
But it can not throw peer class of that exception & superclass of that exception. Eg.

  
class SuperException{}
class SubException extends SuperException{}

class A{
public void methodA()throws SuperException{}
}
class B extends A
public void methodA()throws SuperException, SubException{}
}
  

This code will work because overridden method is throwing same & subclass of that exception

[K. Tsang]

You understand what overriding is right? If not, overriding allows a subclass to re-define a method it inherits from it's superclass
* overriding methods:
* appear in subclasses
* have the same name as a superclass method
* have the same parameter list as a superclass method
* have the same return type as as a superclass method
* the access modifier for the overriding method may not be more restrictive than the access modifier of the superclass method
- if the superclass method is public, the overriding method must be public
- if the superclass method is protected, the overriding method may be protected or public
- if the superclass method is package, the overriding method may be packagage, protected, or public
- if the superclass methods is private, it is not inherited and overriding is not an issue
* the throws clause of the overriding method may only include exceptions that can be thrown by the superclass method, including it's subclasses

As for exceptions example:

class LBException extends Exception {}
class LBException1 extends LBException {}

//In superclass:
    public void testEx() throws LBException {        
        throw new LBException();        
    }    

//In subclass:
    public void testEx() throws LBException1 {    
        throw new LBException1();        
    }    
//overriding is allowed as LBException1 thrown in the subclass is itself a subclass of the exception LBException thrown in the superclass method