Spring MVC 2.5 annotation 学习

   想搞一个趁手的快速开发框架，maven2,spring2.5，hibernate3.3肯定是少不了的。展现层在Struts2和Spring MVC间犹豫了好久，也看了javaeye上对2个框架的很多讨论。spring2.5 mvc号称是基于annotation的，controller可以是pojo，而且可以极大的减少配置。这可是挺吸引人的功能，于是花点时间学习下，顺便记下自己的学习过程。

   web.xml配置就是标准的spring配置：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

 <display-name>test</display-name>
 <context-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>classpath:applicationContext*.xml</param-value>
 </context-param>

 <!-- Character Encoding filter -->
 <filter>
  <filter-name>encodingFilter</filter-name>
  <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
  <init-param>
   <param-name>encoding</param-name>
   <param-value>UTF-8</param-value>
  </init-param>
 </filter>

 <filter-mapping>
  <filter-name>encodingFilter</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>

 <!--Spring ApplicationContext 载入 -->
 <listener>
  <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
 </listener>

 <servlet>
        <servlet-name>simple</servlet-name>
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>simple</servlet-name>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>
</web-app>

 
 applicationContext.xml 只是空的schema定义：

<?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:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context-2.5.xsd">
    <context:annotation-config />
</beans>

 

   重点是simple-servlet.xml，这个文件名需要和web.xml中定义的name匹配

<?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: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-2.5.xsd
                http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd">
    
    <!--
        - The controllers are autodetected POJOs labeled with the @Controller annotation.
    -->
    <context:component-scan base-package="test"/>
    
    <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver"
        p:prefix="/WEB-INF/jsp/" p:suffix=".jsp" />
</beans>

 为了简单，我只做了test包，所以base-package="test"。

 我做了2个页面，一个MultiController，这个对应springmvc早期版本的MultiActionController，就是多个url映射到一个controller中.代码简化了很多:

package test;

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

@Controller
public class MultiController {
	@RequestMapping("/hello.html")
	public String sayHello(Model model) {
		model.addAttribute("say", "hello");
		return "test";
	}
	
	@RequestMapping("/nihao.html")
	public String sayHello2(Model model) {
		model.addAttribute("say", "nihao");
		return "test";
	}	
}

 

 通过RequestMapping 注解，可以方便的匹配url，再也不需要xml和java两边修改了。

 

还有一个PersonForm，就是通常的对象的编辑

 

package test;

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.support.SessionStatus;

@Controller
@RequestMapping("/person.html")
public class PersonForm {
	private static Person person = new Person();

	@RequestMapping(method = RequestMethod.GET)
	public String setupForm(@RequestParam("id") long id, ModelMap model,
			HttpServletRequest request) {
		String s = request.getParameter("id");
		System.out.println("getId " + s);
		model.addAttribute("person", getPerson(id));
		return "personForm";
	}

	@RequestMapping(method = RequestMethod.POST)
	public String processSubmit(@ModelAttribute("person") Person person,
			BindingResult result, SessionStatus status) {
		if (result.hasErrors()) {
			return "personForm";
		} else {
			PersonForm.person = person;
			System.out.println("person name set to:" + person.getName());
			status.setComplete();
			return "redirect:person.html?id=" + person.getId();
		}
	}

	private Person getPerson(long id) {
		return person;
	}

}

 

 setupForm方法名无所谓，关键是@RequestMapping注解，String s = request.getParameter("id");其实是多余的，我是为了证实可以在方法中加入多种参数，具体参看spring2.5 reference 13.11.4. Supported handler method arguments and return types

 

  附件是源码，使用的maven，只要下载下来，解压到任意目录，cmd进入目录，mvn jetty:run就可以运行了， http://localhost:8080/ 即可访问。

 

  代码中加了一个RunJetty类，可以方便的在IDE中直接运行Jetty，相关最小依赖包已经在pom.xml中定义，jetty-config.xml是它的简单配置，可以修改端口号和app，目前是8080和src/main/webapp。 cmd中运行mvn eclipse:eclipse就可以生成项目，然后eclipse import项目，就可以直接在RunJetty类上 run和debug，访问路径和使用mvn jetty:run相同。