web application with spring mvc example

Web Application With Spring MVC Example

Hello Readers, in this tutorial we are going to see how to create a web application with spring MVC (Model View Controller).

Basically spring MVC is a java framework which is used to create a web applications. It is has all the basic features of core spring so don’t think too much about it.

The spring web MVC framework is designed around DispatcherServlet class (which extends FrameWorkServlet) that dispatches the requests to handlers, with configurable handler mappings, view resolution, locale and theme resolutions as well as support for uploading files(ref : spring 17.1 part V).

In a simple word we may say DispatcherServlet is a class that receives the incoming request and maps it to the appropriate controllers which resolve the views.

So let’s begin by creating a model or entity class.

1 : Alien.java  

package com.ma3.model;

import java.io.Serializable;

public class Alien implements Serializable {

     private static final long serialVersionUID = 1L;

     private Integer id;

     private String name;

     private String planet;

     /**

      * @return the id

      */

     public Integer getId() {

          return id;

     }

     /**

      * @param id the id to set

      */

     public void setId(Integer id) {

          this.id = id;

     }

     /**

      * @return the name

      */

     public String getName() {

          return name;

     }

     /**

      * @param name the name to set

      */

     public void setName(String name) {

          this.name = name;

     }

     /**

      * @return the planet

      */

     public String getPlanet() {

          return planet;

     }

     /**

      * @param planet the planet to set

      */

     public void setPlanet(String planet) {

          this.planet = planet;

     }

     @Override

     public String toString() {

          return "Alien [id=" + id + ", name=" + name + ", planet=" + planet + "]";

     }

}

2 : Now add the following dependencies in 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/xsd/maven-4.0.0.xsd">

     <modelVersion>4.0.0</modelVersion>

     <groupId>TestWebb</groupId>

     <artifactId>TestWebb</artifactId>

     <version>0.0.1-SNAPSHOT</version>

     <packaging>war</packaging>

     <properties>

          <org.springframework.version>4.2.6.RELEASE</org.springframework.version>

     </properties>

     <dependencies>

          <dependency>

              <groupId>junit</groupId>

              <artifactId>junit</artifactId>

              <version>4.12</version>

              <scope>test</scope>

          </dependency>

          <!-- Spring MVC support -->

          <dependency>

              <groupId>org.springframework</groupId>

              <artifactId>spring-webmvc</artifactId>

              <version>${org.springframework.version}</version>

          </dependency>

          <dependency>

              <groupId>org.springframework</groupId>

              <artifactId>spring-web</artifactId>

              <version>${org.springframework.version}</version>

          </dependency>

          <!-- Tag libs support for view layer -->

          <dependency>

              <groupId>javax.servlet</groupId>

              <artifactId>jstl</artifactId>

              <version>1.2</version>

              <scope>runtime</scope>

          </dependency>

          <dependency>

              <groupId>taglibs</groupId>

              <artifactId>standard</artifactId>

              <version>1.1.2</version>

              <scope>runtime</scope>

          </dependency>

     </dependencies>

     <build>

          <testSourceDirectory>src/main/test</testSourceDirectory>

          <plugins>

              <plugin>

                   <artifactId>maven-war-plugin</artifactId>

                   <version>3.2.1</version>

                   <configuration>

                        <warSourceDirectory>WebContent</warSourceDirectory>

                   </configuration>

              </plugin>

          </plugins>

     </build>

</project>

3 : Now create AlienDao.java interface.

package com.ma3.dao;

import java.util.List;

import com.howtodoinjava.demo.model.Alien;

public interface AlienDAO {

            public List<Alien> getAllAliens();

}

4 : Now create AlienDaoImpl.java (annotated with @Repository) class which implement ALienDao.java interface.

package com.ma3.dao;

import java.util.ArrayList;

importjava.util.List;

import org.springframework.stereotype.Repository;

import com.howtodoinjava.demo.model.Alien;

@Repository

public class AlienDAOImpl implements AlienDAO {

            public List<Alien> getAllAliens() {

                        List<Alien> aliens = new ArrayList<Alien>();

                        Alien alien1 = new Alien();

                        alien1.setId(1);

                        alien1.setName("Alien1");

                        alien1.setPlanet("Mars");

                        aliens.add(alien1);

                        Alien alien2 = new Alien();

                        alien2.setId(2);

                        alien2.setName("Alien2");

                        alien2.setPlanet("X-Planet");

                        aliens.add(alien2);

                        return aliens;

            }

}

5 : Now create  AlienManager.java interface.

package com.ma3.AlienManager;

import java.util.List;

import com.howtodoinjava.demo.model.Alien;

public interface AlienManager {

            public List<Alien> getAllAliens();

}

6 : Now create AlienManagerImpl.java class (which is annotated with @Service annotation) which implements AlienManager.java interface.

package com.ma3.AlienManager;

import  java.util.List;

import  org.springframework.beans.factory.annotation.Autowired;

import  org.springframework.stereotype.Service;

import com.howtodoinjava.demo.dao.AlienDAO;

import com.howtodoinjava.demo.model.Alien;

@Service

public class AlienManagerImpl implements AlienManager {

            @Autowired

            AlienDAO empDao;

            public List<Alien> getAllAliens() {

                        return empDao.getAllAliens();

            }

}

7 : Now create AlienController.java which is annotated with @Controller annotation which indicates that it is a controller of our application and DispatcherServlet class will looks for it.

package com.ma3.controller;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Controller;

import org.springframework.ui.Model;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import com.howtodoinjava.demo.AlienManager.AlienManager;

@Controller

public class AlienController {

     @Autowired

     AlienManager manager;

     @RequestMapping(value = "/getAllAliens", method = RequestMethod.GET)

     public String getAllAliens(Model model) {

          model.addAttribute("aliens", manager.getAllAliens());

          return "displayAlien";

     }

}

8 : WEB-INF/web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">

  <display-name>TestWebb</display-name>

  <welcome-file-list>

    <welcome-file>index.jsp</welcome-file>

  </welcome-file-list>

  

  <servlet>

        <servlet-name>spring-applicationContext</servlet-name>

            <servlet-class>

                org.springframework.web.servlet.DispatcherServlet

            </servlet-class>

        <load-on-startup>1</load-on-startup>

    </servlet>

    <servlet-mapping>

        <servlet-name>spring-applicationContext</servlet-name>

        <url-pattern>/</url-pattern>

    </servlet-mapping>

   

</web-app>

9 : WEB-INF/spring-applicationContext-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>

<beans 

    xmlns="http://www.springframework.org/schema/beans" 

    xmlns:tx="http://www.springframework.org/schema/tx"

    xmlns:context="http://www.springframework.org/schema/context"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

    xmlns:p="http://www.springframework.org/schema/p" 

    xsi:schemaLocation="http://www.springframework.org/schema/beans  

http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

http://www.springframework.org/schema/tx

http://www.springframework.org/schema/tx/spring-tx-3.0.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context.xsd">

    <context:annotation-config />

    <context:component-scan base-package="com.ma3" />

    

    

    <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />

    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />

    

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">

        <property name="prefix" value="/WEB-INF/views/" />

        <property name="suffix" value=".jsp" />

    </bean>

</beans>

10 : WEB-INF/views/displayAlien.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<html>

<head>

<title>Spring MVC Hello Alien</title>

</head>

<body>

          <div>

              <h2>All Aliens</h2>

              <table border="3" width="20%">

                   <tr>

                        <th>Id</th>

                        <th>Name</th>

                        <th>Planet</th>

                   </tr>

                   <c:forEach items="${aliens}" var="aliens">

                        <tr>

                             <td>${aliens.id}</td>

                             <td>${aliens.name}</td>

                             <td>${aliens.planet}</td>

                        </tr>

                   </c:forEach>

              </table>

          </div>

</body>

</html>

12 : WEB-INF/index.jsp

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

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

<title>Insert title here</title>

</head>

<body>

<a href="getAllAliens">Show Aliens</a>

</body>

</html>

13 : Now run the application (I am using tomcat 9.0).

Go to this URL : http://localhost:8080/TestWebb/ the following default index.jsp will be displayed with a link called Show Alien, click on that link to see all aliens.

 

When you click on the Show Aliens the below screen will be displayed.

Tested on eclipse 2019-06, GOOD LUCK.

In the next tutorial we will see the same example with spring and hibernate integration.

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