springMVC笔记（二）- SimpleUrlHandlerMapping
SpringMVC里面有许多HandlerMapping，对这块还不太了解，所以决定了解一下这些东东的作用。
先来看第一个：org.springframework.web.servlet.handler.SimpleUrlHandlerMapping
官方的api文档解释如下：
Implementation of the org.springframework.web.servlet.HandlerMapping interface to map from URLs to request handler beans.
简单来说，就是实现了HandlerMapping接口，处理url到bean的映射，比如下面这些映射：
/welcome.html=ticketController
/show.html=ticketController
一个url对应一个bean，但是这个bean有个要求，就是实现Controller接口，下面看一个实例。
1.Controller如下：
1 package com.springmvc.demo.controller; 2 3 import javax.servlet.http.HttpServletRequest; 4 import javax.servlet.http.HttpServletResponse; 5 6 import org.springframework.stereotype.Controller; 7 import org.springframework.web.servlet.ModelAndView; 8 import org.springframework.web.servlet.mvc.AbstractController; 9 10 @Controller 11 public class SimpleController extends AbstractController { 12 13 @Override 14 protected ModelAndView handleRequestInternal(HttpServletRequest request, 15 HttpServletResponse response) throws Exception { 16 System.out.println("SimpleController..."); 17 System.out.println(request.getParameter("username")); 18 ModelAndView mv = new ModelAndView("simpleController"); 19 mv.addObject("msg", "hello,SimpleController"); 20 return mv; 21 } 22 23 }
2.为了对比，再建一个Controller，这个没有实现Controller接口，而是使用注解：
1 package com.springmvc.demo.controller; 2 3 import javax.servlet.http.HttpSession; 4 5 import org.springframework.stereotype.Controller; 6 import org.springframework.ui.ModelMap; 7 import org.springframework.validation.BindingResult; 8 import org.springframework.web.bind.annotation.ModelAttribute; 9 import org.springframework.web.bind.annotation.RequestMapping; 10 import org.springframework.web.bind.annotation.RequestParam; 11 import org.springframework.web.servlet.ModelAndView; 12 13 import com.springmvc.demo.model.User; 14 15 @Controller 16 @RequestMapping("/user") 17 public class UserController { 18 19 @RequestMapping("/add") 20 public ModelAndView addUser(@RequestParam String username, 21 @RequestParam String password, 22 @RequestParam int id, 23 HttpSession session){ 24 25 ModelAndView mv = new ModelAndView(); 26 mv.setViewName("hello"); 27 User u = new User(); 28 u.setUsername(username); 29 u.setPassword(password); 30 u.setId(id); 31 mv.addObject("user", u); 32 session.setAttribute("user", u); 33 34 return mv; 35 } 36 37 /*@ModelAttribute 38 public User getUser(){ 39 User u = new User(); 40 u.setId(12); 41 return u; 42 }*/ 43 44 @RequestMapping("/preAddUser") 45 public String preAddUser(ModelMap map){ 46 User u = new User(); 47 map.addAttribute("user", u); 48 return "index"; 49 } 50 51 @RequestMapping("/addUser") 52 public String addUser2(@ModelAttribute("user") User user,BindingResult result,ModelMap map){ 53 if(user.getUsername().equals("yang")){ 54 map.addAttribute("user", user); 55 return "index"; 56 } 57 /*ModelAndView mv = new ModelAndView(); 58 59 mv.setViewName("hello"); 60 mv.addObject("user", user);*/ 61 62 return "hello"; 63 } 64 65 }
3.页面simpleController.jsp：
1 <!DOCTYPE html> 2 <html> 3 <body> 4 5 <form action="/springmvc/simpleController" method="post"> 6 <input type="text" name="username"/> 7 <input type="text" name="password"/> 8 <!-- <input type="text" name="id"/> --> 9 <input type="submit" value="submit" /> 10 </form> 11 </body> 12 </html>
4.MVC配置文件：
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" 4 xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" 5 xsi:schemaLocation=" 6 http://www.springframework.org/schema/beans 7 http://www.springframework.org/schema/beans/spring-beans.xsd 8 http://www.springframework.org/schema/context 9 http://www.springframework.org/schema/context/spring-context.xsd 10 http://www.springframework.org/schema/mvc 11 http://www.springframework.org/schema/mvc/spring-mvc.xsd"> 12 13 <context:component-scan base-package="com.springmvc.demo.controller" /> 14 15 <!-- <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping" /> 16 <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter" /> --> 17 <!-- <mvc:default-servlet-handler/> --> 18 <!-- <mvc:annotation-driven /> --> 19 <!-- <mvc:resources location="/resource/images/" mapping="/images/**" /> --> 20 <bean id="simpleController" class="com.springmvc.demo.controller.SimpleController"></bean> 21 22 <bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> 23 24 <property name="urlMap"> 25 <map> 26 <entry key="/simpleController" value-ref="simpleController" /> 27 </map> 28 </property> 29 </bean> 30 31 <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> 32 <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> 33 <property name="prefix" value="/" /> 34 <property name="suffix" value=".jsp" /> 35 </bean> 36 37 38 </beans>
测试一：
访问simpleController.jsp，点击提交，访问正常
测试二：
访问/user/add，显示404
总结：
SimpleUrlHandlerMapping只支持实现了Controller接口的bean，且还需要在其属性里进行url路径-->bean的映射，不支持@RequestMapping注解，所以这个SimpleUrlHandlerMapping功能很有限
注：还可以使用mappings属性进行配置，效果是一样的：
<!-- mappings是一Properties对象 -->
<property name="mappings"> <props> <prop key="/simpleController">simpleController</prop> </props> </property>