Mock Exam Question

[Nilesh Raje]

Hi Friends,

I can across this mockexam Question on Jiris..!
Which statements are TRUE regarding the following code? Mark

Please select two correct answers.

import javax.servlet.*;
import javax.servlet.http.*;

public class MyServlet extends GenericServlet {

public void init() { //1
// Do something
}

public void init(ServletConfig config) //2
throws ServletException{
// Do something
super.init(config); //3
}

public void destroy() { //4
// Do something
}

public void service(ServletRequest req, //5
ServletResponse res) {
// Do something
}
}

A : Method //1 is necessary for this code to compile
B : Method //2 is necessary for this code to compile
C : Line //3 is necessary for this code to run
D : Method //4 is necessary for this code to compile
E : Method //5 is necessary for this code to compile


Explanation

You need to override the service() method when you extends GenericServlet.
You need to call super.init(config) if you override this method


I dont remember the answer given but i guess its C and E from the explanation given. Wanted to know if the explanation given is right.!Can we overide the Service menthod is we extend Generic Servlet??

[Niranjan Deshpande]

nilesh -

the class GenericServlet implements the interface Servlet.
But the class doesnt implement all the methods, it doesnt implement the
service(ServletRequest, ServletResponse) method, and thats why the GenericServlet class is declared abstract.

Since the servlet in the question extends the GenericServlet, option E is correct !

and about option C its correct because -

the code overrides the init(ServletConfig) nethod. Thus the container wont call the method (this method has a call to the init( ) method )that is inherited from the class GenericServlet. So in order that your init( ) method should be called, you must place a super.init(ServletConfig) method [ in your init(ServletConfig) ], which in turn has a call to the init( ) method that is already coded at line 1 .

hope this doesnt confuse you !

[wise owen]

What if we override the init(ServletConfig) and don't call super(ServletConfig)?