JSP-Servlet

Return Object List in Ajax 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>

		<dependency>
			<groupId>com.google.code.gson</groupId>
			<artifactId>gson</artifactId>
			<version>2.8.5</version>
		</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.

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

Create Entities

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

package com.demo.entities;

import java.io.Serializable;

public class Product implements Serializable {

	private static final long serialVersionUID = 1L;

	private String id;
	private String name;
	private double price;

	public Product() {
	}

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

	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;
	}

}




Create Servlets

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

Demo Servlet

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

package com.demo.servlets;

import java.io.IOException;

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

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

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

}

Ajax Servlet

In com.demo.servlets package, create new Servlet named AjaxServlet as below:

package com.demo.servlets;

import java.io.IOException;
import java.io.PrintWriter;
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 com.demo.entities.Product;
import com.google.gson.Gson;

@WebServlet("/ajax")
public class AjaxServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;

	public AjaxServlet() {
		super();
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		Gson gson = new Gson();
		List<Product> products = new ArrayList<Product>();
		products.add(new Product("p01", "name 1", 20));
		products.add(new Product("p02", "name 2", 21));
		products.add(new Product("p03", "name 3", 22));
		PrintWriter out = response.getWriter();
		out.print(gson.toJson(products));
		out.flush();
		out.close();
	}

	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 files as below:

Index Page

In src\main\webapp\demo 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"%>
<html>
<head>
<title>Ajax</title>
<script src="${pageContext.request.contextPath }/assets/js/jquery.js"></script>
<script type="text/javascript">
	$(document).ready(function() {

		$('#buttonDisplay').click(function() {
			$.ajax({
				type : 'GET',
				headers : {
					Accept : "application/json; charset=utf-8",
					"Content-Type" : "application/json; charset=utf-8"
				},
				url : '${pageContext.request.contextPath }/ajax',
				success : function(result) {
					var products = $.parseJSON(result);
					var s = '';
					for(var i = 0; i < products.length; i++) {
						s += 'Id: ' + products[i].id + '<br>';
						s += 'Name: ' + products[i].name + '<br>';
						s += 'Price: ' + products[i].price + '<br>';
						s += '----------------------<br>';
					}
					$('#result').html(s);
				}
			});
		});

	});
</script>
</head>
<body>

	<h3>Return Object List in Ajax</h3>
	<form>
		<input type="button" value="Dislay" id="buttonDisplay">
		<br>
		<span id="result"></span>
	</form>

</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

Click Display button:

Output


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