Spring DispatcherServlet and Spring MVC

Original chapter: Understanding the dispatcher- servlet.xml. The text and examples below are preserved from the historical source; read the corrections above before using them.

In Spring Web MVC, DispatcherServlet class works as the front controller. It is responsible for managing the flow of the spring MVC application.

DispatcherServlet is also like normal servlet need to be configured in web.xml

Section 18.1: dispatcher-servlet.xml

This is the important configuration file where we need to specify the ViewResolver and View components.

The context:component-scan element defines the base-package where DispatcherServlet will search the controller class.

Here, the InternalResourceViewResolver class is used for the ViewResolver.

The prefix+string returned by controller+suffix page will be invoked for the view component.

This xml file should be located inside the WEB-INF directory.

Source example · PDF page 65

<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:context="http://www.springframework.org/schema/context"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">

   <context:component-scan base-package="com.srinu.controller.Employee" />

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

Section 18.2: dispatcher servlet configuration in web.xml

In this XML file, we are specifying the servlet class DispatcherServlet that acts as the front controller in Spring Web MVC. All the incoming request for the HTML file will be forwarded to the DispatcherServlet.

Source example · PDF page 65

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
   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_2_5.xsd">
<servlet>
   <servlet-name>spring</servlet-name>
   <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
   <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
   <servlet-name>spring</servlet-name>
   <url-pattern>*.html</url-pattern>
</servlet-mapping>
</web-app>