Building Web Applications with JSP and Servlets

Tutorial 5 of 5

Building Web Applications with JSP and Servlets

Introduction

This tutorial aims to guide you through the process of building a complete web application using JavaServer Pages (JSP) and Servlets.

By the end of this tutorial, you will understand:
- How to handle HTTP requests and responses
- How to create dynamic web content using JSP and Servlets

Before you begin, you should have a basic understanding of the following:
- Java programming
- HTML
- HTTP protocol

Step-by-Step Guide

1. Setting Up Your Development Environment

First, you need to set up your development environment. This involves installing Java Development Kit (JDK) and an IDE like Eclipse or IntelliJ. You'll also need a server such as Apache Tomcat to run your web application.

2. Understanding Servlets

A Servlet is a Java class that handles requests from the client and sends a response back to the client. It extends the capabilities of the server and allows us to build dynamic web pages.

3. Understanding JSP

JSP is a technology for developing web pages that support dynamic content. It uses tags to encapsulate the logic that generates the content for the page.

Code Examples

1. Creating a Servlet

Below is a simple example of a Servlet.

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;

public class HelloWorld extends HttpServlet {
  public void doGet(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {
    PrintWriter out = response.getWriter();
    out.println("Hello, World!");
  }
}

This Servlet will return "Hello, World!" when accessed.

2. Creating a JSP Page

Here's a basic JSP page.

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>My First JSP Page</title>
</head>
<body>
<%= "Hello, World!" %>
</body>
</html>

This JSP page will display "Hello, World!" when accessed.

Summary

In this tutorial, we've covered the basics of building a web application with JSP and Servlets. We've learned how to handle HTTP requests, how to create dynamic web content, and we've seen examples of a basic Servlet and JSP page.

To continue learning, you might want to explore:
- MVC architecture
- JSTL (JSP Standard Tag Library)
- Java Database Connectivity (JDBC)

Practice Exercises

Create a Servlet that returns your name and today's date on separate lines.
Create a JSP page that displays a list of your favorite movies or books. Use a Java array to store the data.

Here's a hint for the first exercise:

import java.util.Date;
...
PrintWriter out = response.getWriter();
out.println("Your Name");
out.println(new Date());

For the second exercise, you might find the JSP expression language helpful:

<% String[] movies = {"Movie 1", "Movie 2", "Movie 3"}; %>
<ul>
  <% for (String movie : movies) { %>
    <li><%= movie %></li>
  <% } %>
</ul>

Keep practicing and exploring different features of JSP and Servlets!