Showing posts with label Spring. Show all posts
Showing posts with label Spring. Show all posts

Tuesday, July 31, 2007

"Hello, world" with Spring MVC

Recently I've started using of Srping MVC for my web apps. So what you need to get started with spring MVC:

1) Download Spring framework and put spring.jar to web server lib path.
2) Add DispathServlet mapping to web.xml
<servlet>
  <servlet-name><strong>spring</strong></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>/index.jsp</url-pattern>
</servlet-mapping>


3) We have called servler instance as spring, so we should create a spring-servlet.xml at WEB-INF.


<xml>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">

<beans>

      <bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
              <property name="mappings">
                     <props>
                             <prop key="/*.jsp">dispatchController</prop>
                     </props>
             </property>
     </bean>

    <bean id="dispatchController" class="my.SimpleController">

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

</beans>
</xml>

We described 3 beans here.
urlMaping - is a mapping bean. It should not be registered manually. Spring will automatically parse it during initialization.
dispatchController - is a bean, which will be dispath all requests of *.jsp pages. We write class="my.SimpleController", so we need to create class SimpleController later.
viewResolver - is a bean? which will add prefix and suffix to views for creating valid request.

4) Create class my.SimpleController
package my;

import org.springframework.web.servlet.mvc.Controller;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class SimpleController implements Controller {
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView mav = new ModelAndView("index");
        return mav;
    }
}

This class will dispath all requests to the "index" view. Then "index" view will be changed to "/WEB-INF/jsp/index.jsp" by viewResolver bean.

5) Create "/WEB-INF/jsp/index.jsp".
<html>
  <body>
     "Hello, world!" with Spring MVC.
  </body>
</html>


That's all.