For understanding anything it is best to gets hand on. Let us try creating a simple spring app using spring MVC framework (This tutorial assumes Eclipse IDE)
0. Create a sample J2EE project (or Spring project if you already have it installed)
1. Download Spring http://www.springsource.org/spring-community-download and include jars to lib folder.
2. Modify web.xml to direct all the requests ending with .do to spring MVC’s fromt controller servlet (DispatcherServlet)
<servlet>
<servlet-name>springapp</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springapp</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
3. Spring by default assumes webapplication context to be present in <servletname>-servlet.xml. In this case create springapp-servlet.xml.
4. Spring is mostly annotation driven, to take advantage of same add following to springapp-servlet.xml
<?xml version=”1.0″ encoding=”UTF-8″?>
<beans xmlns=”http://www.springframework.org/schema/beans”
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:context=”http://www.springframework.org/schema/context”
xsi:schemaLocation=”http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd”
><!– JSR-303 support will be detected on classpath and enabled automatically –>
<mvc:annotation-driven />
<!– Activates various annotations to be detected in bean classes –>
<context:annotation-config /><!– Tell Spring where to automatically detect controllers –>
<context:component-scan base-package=”spring.sample.controllers” />
<!– Define Simple View Resolvers –>
<bean id=”viewResolver” class=”org.springframework.web.servlet.view.InternalResourceViewResolver”>
<property name=”viewClass” value=”org.springframework.web.servlet.view.JstlView”></property>
<property name=”prefix” value=”/WEB-INF/jsp/”></property>
<property name=”suffix” value=”.jsp”></property>
</bean></beans>
We have done two things, first, we told spring that all our controllers will be in spring.sample.controllers and second look for view files under /WEB-INF/jsp folder
5. As we are going for annotations driven approach, we can use any POJO file as controller. It just needs to be in spring.sample.controller.
package spring.sample.controllers;
@Controller
/*this url automatically gets redirected here*/
@RequestMapping(value = “/mylink”)
public class SampleController {@RequestMapping(method = RequestMethod.GET)
public ModelAndView login() {
String message = “Welcome to the Spring 3.0 version!”;
return new ModelAndView(“welcome”, “message”, message);
}
6. And finally a simple welcome.jsp
<%@ page language=”java” contentType=”text/html; charset=UTF-8″
pageEncoding=”UTF-8″
%>
<!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=UTF-8″>
<title>Welcome to Spring</title>
</head>
<body>${message}
</body>
</html>