How to Properly Handle Exceptions in a JSP/Servlet App?

Question

How do you properly handle errors encountered in a servlet? Right now, the app that I inherited (uses only plain JSP/Servlet) has a superclass called Controller

Answer 1

Or you can intercept all your exceptions using a servlet:

    ErrorServlet
    com.domain.MyErrorServlet
    

ErrorServlet
    /error


    java.lang.Throwable
    /error

Then in the servlet you can handle the exception like this

public class MyErrorServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response){
       Throwable throwable = (Throwable) request.getAttribute("javax.servlet.error.exception");
       // You can log the exception, send to email, etc
    }
}