Spring 4 – Spring MVC Hello World Example

In this example we will learn how to write a Simple Web based Hello World application using Spring MVC framework using Spring 4 api.

Folder Structure :

  1. Create a Dynamic Web Project Spring4Tutorial and create a package for our src files com.javainterviewpoint
  2. Place the required jar files under WEB-INF/Lib 

    spring-aop-4.2.4.RELEASE.jar
    spring-beans-4.2.4.RELEASE.jar
    spring-context-4.2.4.RELEASE.jar
    spring-core-4.2.4.RELEASE.jar
    spring-expression-4.2.4.RELEASE.jar
    spring-web-4.2.4.RELEASE.jar
    spring-webmvc-4.2.4.RELEASE.jar
    commons-logging-1.2.jar

  3. Create the Java classes HelloWorldExample.java under  com.javainterviewpoint folder.
  4. Place the index.jsp under “WebContent” directory.
  5. Create a folder “Jsp” under WEB-INF directory, for keeping our jsp files. Keep welcome.jsp under that folder
  6. Place the web.xml  and SpringConfig-servlet.xml under the WEB-INF directory

index.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
 pageEncoding="ISO-8859-1"%>
 <%@ taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
<!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>Spring 4 Hello World Example - Spring MVC</title>
</head>
   <body>
    <br>
      <div style="text-align:center">
         <h3>
            <a href="welcoming.html">Click here to See the Welcome Message... </a>
         </h3>
      </div>
    </body>
</html>

Our index page has nothing but a hyperlink which direct to our controller calling “welcome.html”

HelloWorldExample.java

package com.javainterviewpoint;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class HelloWorldExample
{
    @RequestMapping(value = "/welcoming", method = RequestMethod.GET)
    public ModelAndView dispWelcomeMessage() 
    {
        String message = "Welcome to Spring 4 - Spring MCV Hello World Example !!..";

        return new ModelAndView("welcome","message",message);
    }
}
  • We have annotated our “HelloWorldExample” class with @Controller annotation which tells Spring Container to treat this class as a Controller.
  • @RequestMapping annotation on top of dispWelcomeMessage() redirects the request to this method, when the request given is “welcoming” and it can take only GET request which is denoted by method=RequestMethod.GET
  • Finally return to the view page “welcome” along with our custom message passed to the ModelAndView class constructor
  • Rendering the view will be taken care by “InternalResourceViewResolver” which is configured in our “SpringConfig-servlet.xml”

Welcome.jsp

Our Welcome page containts the EL for displaying the message which is passed from our controller

<%@ 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>
 <h2>${message}</h2>
</body>
</html>

web.xml

The web.xml has everything about the application that a server needs to know, which is placed under the WEB-INF directory. <servlet-name> contains the name of the SpringConfiguration , when the DispatcherServlet is initialized the framework will try to load a configuration file [servlet-name]-servlet.xml” under the WEB-INF directory.

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 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>SpringMVCFormHandling</display-name>
   <welcome-file-list>
       <welcome-file>index.html</welcome-file>
       <welcome-file>index.htm</welcome-file>
       <welcome-file>index.jsp</welcome-file>
       <welcome-file>default.html</welcome-file>
       <welcome-file>default.htm</welcome-file>
       <welcome-file>default.jsp</welcome-file>
   </welcome-file-list>
   <servlet>
       <servlet-name>SpringConfig</servlet-name>
       <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
   </servlet>
   <servlet-mapping>
      <servlet-name>SpringConfig</servlet-name>
      <url-pattern>/</url-pattern>
   </servlet-mapping>
</web-app>

SpringConfig-servlet.xml

The SpringConfig-servlet.xml is also placed under the WEB-INF directory.

  • <context:component-scan> will let the Spring Container to search for all the annotation under the package “com.javainteriviewpoint”.
  • <mvc:annotation-driven/> annotation will activate the @Controller, @RequestMapping, @Valid etc annotations.
  • The view is resolved through “org.springframework.web.servlet.view.InternalResourceViewResolver” which searches for the jsp files under the /WEB-INF/Jsp/ directory.
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:context="http://www.springframework.org/schema/context"
 xmlns:mvc="http://www.springframework.org/schema/mvc" 
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns:p="http://www.springframework.org/schema/p"
 xmlns:jee="http://www.springframework.org/schema/jee"
 xsi:schemaLocation=
 "http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
 http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
 http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd" >
 
    <mvc:annotation-driven/>
 
    <context:component-scan base-package="com.javainterviewpoint"></context:component-scan>
 
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/Jsp/"></property>
        <property name="suffix" value=".jsp"></property>
     </bean>
 </beans>

How Everything works?

  •  Upon running index.jsp and click on the “Click here to the Welcome Message” link.
  • Once you click on the link, controll will be passed to the DispatcherServlet mentioned in the web.xml
<servlet-name>SpringConfig</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  • Then the DispatcherServlet passes the controll to the  HelloWorldExample.java(@Controller) .
  • The action “Welcoming.html” be mapped in the controller, the controller verifies it under the @RequestMapping annotation.
  • Now dispWelcomeMessage() method will be called, it simply returns the ModelAndView Object with the three parameter.
    • 1st Parameter – View Name(welcome)
    • 2nd Parameter -Key to access the message
    • 3rd Parameter – Value
return new ModelAndView("welcome","message",message);
  • Through the ViewResolver (InternalResourceViewResolver) mapped in the SpringConfig-servlet.xml , the welcome.jsp page will be resolved and rendered as the output.
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/Jsp/"></property>
<property name="suffix" value=".jsp"></property>
</bean>

Output

URL : http://localhost:8080/Spring4Tutorial/index.jsp

Spring 4 Hello World Example

 

 

 

 

 

Now Click on the HyperLink

Spring 4 Welcome Message

 

 

 

 

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