Tutorial covering JSP 2.2 and Servlets 3.0 with OpenSource Resin Servlet Container: Part 1

Creating your first Servlet

Eclipse: Right Click "Java Resources" in Project Explorer -> New -> Servlet -> Package = com.bookstore.web -> Class Name = BookListServlet -> Click Next -> Remove URL mapping, create new mapping /book/

(That is the last time I will tell you how to create a Servlet in Eclipse.)

Note: This application uses the REST style URL mappings so things that end in / imply you are working with a list (like a directory of files). Thus the URI /book/ implies a collection of books since we want to show a list of books this is a good URI.

Modify the Servlet to only handle the doGet method, change the doGet method to forward to a JSP that we have not created yet that lives in WEB-INF.

package com.bookstore.web;

import java.io.IOException;


import javax.inject.Inject;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.bookstore.BookRepository;

@WebServlet("/book/")
public class BookListServlet extends HttpServlet {

	@Inject
	private BookRepository bookRepo;

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setAttribute("books", bookRepo.listBooks());
		getServletContext().getRequestDispatcher("/WEB-INF/pages/book-list.jsp").forward(request, response);
	}

}

WEB-INF is a meta directory folder for war files. JSPs in the WEB-INF folder can never be loaded directly from a browser. This allows us to force all JSPs to first go through our Servlet tier (controllers) which is essential for a model 2 architecture (a form of MVC tailored for HTTP applications), which we will use throughout the tutorial. Consider putting JSPs in WEB-INF a best practice.

The annotations @WebServlet("/book/") allow us to map this Servlet to handle requests for the URI /book/ as follows:

Bill Digman is a Java EE / Servlet enthusiast and Open Source enthusiast who loves working with Caucho's Resin Servlet Container, a Java EE Web Profile Servlet Container.