This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
I am guessing you are using an old text or tutorial that depends on the dreaded Invoker servlet being configured on your system.
Your web.xml shows that your HelloServlet is not in a package - to avoid future hard to diagnose problems, put ALL classes involved in servlets or JSP in packages and place compiled class files accordingly.
hi the following link will give you instructions of how to config your TomCat server and running programs.. at the begining even i had same kind of problems i have followed those instructions and got my programming working try it