JBridge: Certification Question Of The Day

Which of the following method signatures represent a correct way of overriding the doGet method in HttpServlet? (2 correct answers)

The Answer

B & C are the correct answers. Each throws only one of the two exception types present in the superclass doGet. But that’s OK – an overriding method can throw fewer exceptions than its parent.
To weed out the imposters, you need to know the following:

1. The superclass method doGet has an access modifier of “protected”. Since you can’t reduce visibility in an overridden method, the only access modifiers acceptable are “protected” or “public”. This rules out answer A.
2. The return type for doGet is void, not boolean. This rules out answers D and E.
3. HttpServletException doesn’t exist (at least, not in the javax.servlet packages as delivered). This rules out A and E (again).
4. The correct parameter types for doGet are HttpServletRequest and HttpServletResponse. HttpSession is a type that exists, so the F answer will compile – but it doesn’t override the original method (it overloads doGet rather than overriding it).