Tech Juice

Introduction

Serious Java Web application development requires a lot of different applications. In addition to a JDK, an IDE and an application server you may need a Web application framework, a build system and some form of version control. Unsurprisingly, getting set up for development can be quite the task.

In this post we’ll take a look at setting up a Web application project from start to finish. The software we will use is:

What Are We Building?

Different applications come in different forms.

• A Windows application written in C++ may be compiled to a .exe file.
• Runnable Java GUI applications often come in a JAR (Java ARchive).
• Java Web applications are packaged in WAR and EAR files.

We are building a Web application, so the product of building our project will be a WAR file. The Glassfish application server extracts a WAR file and runs the application inside it. The WAR file also contains a deployment descriptor, web.xml that describes how the application server should run the WAR.

The structure of a WAR file looks like this (source):

Project Setup with Maven Archetypes

Now that we know what we are building, it is time to start setting up the project. The directory/file structure…

Introduction

A Web application is an application that is accessed over a network such as the Internet or an intranet. While the earliest websites served only static web pages, dynamic response generation quickly became possible via CGI scripts, JSPs (JavaServer Pages), servlets, ASPs (Active Server Pages), server-side JavaScripts, PHP, or some other server-side technology.

Java has become a popular language for creating dynamic Web applications over the last 15 years, due to the introduction of servlets, JSP, and frameworks such as JSF and Spring. In this post we give an overview of these technologies, and explain the the major differences between them.

Building Blocks

For the sake of simplicity we distinguish three types of Web application building blocks: servlets, JSPs and frameworks

Servlets

In Java, Web applications consist of servlets. A servlet is a small Java program that runs within a Web server. Servlets receive and respond to requests from Web clients, usually across HTTP. An example of a servlet that takes a request and returns a page with the numbers 1 to 10 is given below.

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