Session in JSP-Servlet

Create Maven Project

On the Eclipse, create a Maven project

Click Next button to select Workspace Location for project

Click Next button to select Archetype for project

Click Next button and enter Project Information:

• Group Id: LearnJSPServletWithRealApps
• Artifact Id: LearnJSPServletWithRealApps
• Package: com.demo

Click Finish button to finish create Maven project

Configure pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>LearnJSPServletWithRealApps</groupId>
	<artifactId>LearnJSPServletWithRealApps</artifactId>
	<packaging>war</packaging>
	<version>0.0.1-SNAPSHOT</version>
	<name>Learn JSP-Servlet with Real Apps</name>
	<url>http://maven.apache.org</url>
	<dependencies>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>3.8.1</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>javax.servlet.jsp.jstl</groupId>
			<artifactId>javax.servlet.jsp.jstl-api</artifactId>
			<version>1.2.1</version>
		</dependency>
		<dependency>
			<groupId>taglibs</groupId>
			<artifactId>standard</artifactId>
			<version>1.1.2</version>
		</dependency>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>javax.servlet-api</artifactId>
			<version>3.1.0</version>
			<scope>provided</scope>
		</dependency>
	</dependencies>
	<build>
		<finalName>LearnJSPServletWithRealApps</finalName>
	</build>
</project>

Configure web.xml

<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
 	<welcome-file-list>
 		<welcome-file>index.jsp</welcome-file>
 	</welcome-file-list>
</web-app>

Redirect Page

Create new JSP file named index.jsp in src\main\webapp folder. This file will redirect to DemoServlet as below:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
<jsp:forward page="demo"></jsp:forward>

Create Entity

Create new package named com.demo.entities. In this package, create new java class named Product.java as below:

package com.demo.entities;

public class Product {

	private String id;
	private String name;
	private double price;
	private int quantity;

	public Product() {
	}

	public Product(String id, String name, double price, int quantity) {
		this.id = id;
		this.name = name;
		this.price = price;
		this.quantity = quantity;
	}

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public double getPrice() {
		return price;
	}

	public void setPrice(double price) {
		this.price = price;
	}

	public int getQuantity() {
		return quantity;
	}

	public void setQuantity(int quantity) {
		this.quantity = quantity;
	}

}

Create Servlets

Create new package named com.demo.servlets. In this package, create new Servlet named DemoServlet as below:

package com.demo.servlets;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

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 javax.servlet.http.HttpSession;

import com.demo.entities.Product;

@WebServlet("/demo")
public class DemoServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;

	public DemoServlet() {
		super();
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		HttpSession session = request.getSession();

		session.setAttribute("age", 20);
		session.setAttribute("username", "acc1");

		Product product = new Product("p01", "name 1", 20, 3);
		session.setAttribute("product", product);

		List<Product> products = new ArrayList<Product>();
		products.add(new Product("p01", "name 1", 20, 3));
		products.add(new Product("p02", "name 2", 11, 2));
		products.add(new Product("p03", "name 3", 14, 6));
		session.setAttribute("products", products);

		request.getRequestDispatcher("demo/index.jsp").forward(request, response);
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
	}

}

Create JSP Pages

Create new folder named demo in src\main\webapp folder. In this folder, create new JSP file named index.jsp as below:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1" isELIgnored="false"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
<title>Demo Page</title>
</head>
<body>

	<h3>Display Simple Values</h3>
	Age: ${sessionScope.age }
	<br> Username: ${sessionScope.username }

	<h3>Display Product Info</h3>
	<table border="1">
		<tr>
			<td>Id</td>
			<td>${sessionScope.product.id }</td>
		</tr>
		<tr>
			<td>Name</td>
			<td>${sessionScope.product.name }</td>
		</tr>
		<tr>
			<td>Price</td>
			<td>${sessionScope.product.price }</td>
		</tr>
		<tr>
			<td>Quantity</td>
			<td>${sessionScope.product.quantity }</td>
		</tr>
		<tr>
			<td>Total</td>
			<td>${sessionScope.product.price * sessionScope.product.quantity }</td>
		</tr>
	</table>

	<h3>Display Product List</h3>
	<table border="1" cellpadding="2" cellspacing="2">
		<tr>
			<th>Id</th>
			<th>Name</th>
			<th>Price</th>
			<th>Quantity</th>
			<th>Sub Total</th>
		</tr>
		<c:forEach var="product" items="${sessionScope.products }">
			<tr>
				<td>${product.id }</td>
				<td>${product.name }</td>
				<td>${product.price }</td>
				<td>${product.quantity }</td>
				<td>${product.price * product.quantity }</td>
			</tr>
		</c:forEach>
	</table>


</body>
</html>

Structure of Maven Project

Run Application

Select project, right click and select Run As/Run on Server menu

Access DemoServlet with following urls as below:

• http://localhost:8081/LearnJSPServletWithRealApps
• http://localhost:8081/LearnJSPServletWithRealApps/demo

Output