As Ricky pointed out, you shouldn't be doing any of that.
Servlets allow ServletException and IOException to be thrown out of their doXXX() methods. The only exception handing you should be doing is to catch other exception types in order to wrap them in a ServletException (as its root cause) and rethrow the exception.
I prefer to be a little more verbose about what went wrong than shown in Ricky's example. Let's assume that a SQLException is thrown while deleting a Thingamambob:
Note that the main reason for the exception and original message are captured as the first parameter, and that the original SQLException is recorded as the root cause via the second parameter.
No booleans. No redirecting or forwarding to error pages in your code.
In your deployment descriptor use the <error-page> element to declare a servlet (or JSP) to handle all errors,
This has numerous advantages. Errors are handled in one place and in a consistent fashion. And you don't have to worry about putting a lot of goop into your servlets and onto your JSPs to handle exceptions.
I prefer to use an error handling servlet that does all the error book-keeping, which then forwards to a user-facing JSP page that let's users know that an error has occured and has been logged. [ January 19, 2007: Message edited by: Bear Bibeault ]