Spring MVC

Make the following changes to the Maven web application we created in the previous step:

1. Add the dependency org.springframework:spring-webmvc:4.2.2.RELEASE

2. Create a folder WEB-INF under /src/main/webapp, then create a file web.xml under WEB-INF with the following content:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
        http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    version="3.0" id="springmvc">

    <display-name>Spring MVC Example</display-name>

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

    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>

</web-app>

This web.xml file specifies a Spring servlet DispatcherServlet which will be loaded when the web application is started (notice the <load-on-startup>), and this servlet is responsible for initializing the Spring servlet context, i.e. creating all the beans specified in a bean configuration file. The default name for the bean configuration file is <dispatcher-servlet-name>-servlet.xml under the WEB-INF folder. In our case, the name of the DispatcherServlet is springmvc (notice the <servlet-name>) so the bean configuration file is springmvc-servlet.xml. During operation DispatcherServlet also serves as the front controller that dispatches requests to the proper controller based on controller URL mapping.

3. Create the Spring bean configuration file springmvc-servlet.xml under WEB-INF as follows:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd  
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-4.2.xsd">

    <mvc:annotation-driven />

    <context:component-scan base-package="springmvc.web" />

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>

</beans>

<mvc:annotation-driven /> enables request dispatching to @Controllers among some other things. <context:component-scan> finds all the annotated beans in springmvc.web and its sub-packages. The InternalResourceViewResolver maps a view name to a JSP file. It has two properties: prefix and suffix, so a view name like "home" would be mapped to a JSP file /WEB-INF/jsp/home.jsp.

And this is pretty much it - your web application is now a Spring MVC application. You can create a controller and a view like the following:

• src/main/java/springmvc/web/controller/HomeController.java
• src/main/webapp/WEB-INF/jsp/home.jsp

And after that you can run the project and check if it works at the URL http://localhost:8080/springmvc/home.html .