SpringMVC框架
Spring的web框架围绕DispatcherServlet设计。 DispatcherServlet的作用是将请求分发到不同的处理器。
DispatcherServlet类似Struts2的中央处理器,SpringMVC框架是被用来取代Struts2的,SpringMVC里面的Controller类似Struts2中Action
这里面我用的版本是SpringMVC3
SpringMVC开发步骤:
一、导入jar包:导入Spring中的aop、asm、aspects、beans、context、context.support、core、expression、jdbc、orm、transaction、web、web.servlet的jar包,另外导入commons-logging-1.1.1.jar包
二、在web.xml中配置DispatcherServlet
<?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"> <!-- 配置DispatcherServlet --> <servlet> <!-- 约定:此名称springmvc必须与配置文件springmvc-servlet.xml保持一致(这里都是springmvc) --> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- 配置:服务器启动时自动加载此Servlet --> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <display-name></display-name> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
三、在WEB-INF中新建springmvc-servlet.xml(其中的springmvc是上面的servlet-name节点的值)
<?xml version="1.0" encoding="UTF-8"?> <!-- 注意下面不要忘记导入mvc、context的schema --> <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: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"> <!-- 开启自动扫描包 --> <context:component-scan base-package="com.kaishengit.web"/> <!-- 开启注解驱动 --> <mvc:annotation-driven/> <!-- 在地址栏访问 "网站根路径 + /404",所跳转到的页面404.jsp --> <mvc:view-controller path="/404" view-name="404"/> <mvc:view-controller path="/500" view-name="500"/> <!-- 配置不用DispatcherServlet拦截的路径(例如:图片、CSS样式、js文件...): 路径可以自己设置,这里面我用static(WebRoot中的文件夹); 其中的"**"代表路径及其子路径 --> <mvc:resources location="/static/" mapping="/static/**"/> <!-- 配置视图解析器 --> <bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> <!-- 上面的配置是固定的,下面两个配置意思是:如果你要访问index视图, 它会自动 prefix(前缀) + index + suffix(后缀), 生成/WEB-INF/views/index.jsp --> <property name="prefix" value="/WEB-INF/views/"/> <property name="suffix" value=".jsp"/> </bean> <!-- 配置文件上传解析器 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 上面配置是固定的,下面是配置上传文件的最大大小 --> <property name="maxUploadSize" value="1000000"/> </bean> </beans>
四、前面配置完全,现在我们正式开始开发
1>新建一个Controller类
a.我们新建一个Controller类(类似Struts2中的Action类):AppController.java
package com.kaishengit.web; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.servlet.ModelAndView; import com.kaishengit.service.UserService; @Controller//1.标记一个Controller public class AppController { /** * Service...:和以前注入方式一样 */ private UserService userService; //2.标记一个请求路径(URL:http://xxx/index.html),请求方式设置为GET(如果设置多种(两种)请求方式:method={RequestMethod.GET,RequestMethod.POST}) @RequestMapping(value="/index.html",method=RequestMethod.GET) public ModelAndView index(){ //ModelAndView的用法:三种 //第一种用法: /*ModelAndView mav = new ModelAndView(); mav.setViewName("index");//要跳转到的view视图 mav.addObject("msg", "Hello,SpringMVC");*///要传递到视图中的值(用法跟request传值相同) //第二种用法 /*ModelAndView mav = new ModelAndView("index"); mav.addObject("msg", "SpringMVC"); mav.addObject("Hi", "Hi,Jack");*/ //第三种用法 ModelAndView mav = new ModelAndView("index", "msg","Hello,SpringMVC"); return mav; } @Autowired public void setUserService(UserService userService) { this.userService = userService; } }
b.在WebRoot中views文件夹中新建一个index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>My JSP 'index.jsp' starting page</title> </head> <body> <!-- 用于显示我们从AppController.java中传的值 --> ${msg }<br/> ${Hi } <!-- 用于显示图片(static是我们在springmvc-servlet.xml配置的不用DispatcherServlet拦截的文件夹);不配置的话,图片无法正常显示 --> <img src="static/img/pretty.png"/> </body> </html>
2>@RequestMapping配置
a.请求的URL:http://xxx/hello/yes.html(两个@RequestMapping配置值组合成一个URL)
package com.kaishengit.web; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.servlet.ModelAndView; @Controller @RequestMapping("/hello") public class HelloController { @RequestMapping("/yes.html") public ModelAndView hello() { return new ModelAndView("hello","message","Hello,SpringMVC"); } }
b.传递参数
第一种方式:
@RequestMapping(value="/hello{id}.html",method=RequestMethod.GET) //@PathVariable指定该变量值是从url中传递过来的(该变量名id和路径中变量id({id})一样) public ModelAndView hello(@PathVariable String id) { System.out.println("id:" + id); return new ModelAndView("hello"); }
第二种方式:
@RequestMapping(value="/hello{id}.html",method=RequestMethod.GET) //@PathVariable("id")必须指定值id(该变量名personid和路径中变量名id({id})不一样) public ModelAndView hello(@PathVariable("id") String personid) { System.out.println("id:" + personid); return new ModelAndView("hello"); }
如果传递多个参数,这里用两个举例:
@RequestMapping(value="/{name}/hello{id}.html",method=RequestMethod.GET) public ModelAndView hello(@PathVariable String id,@PathVariable String name) { System.out.println("id:" + id + "\tname:" + name); return new ModelAndView("hello"); }
3>Controller return types
第一种:跳转到视图
@RequestMapping("/index.html") public String index() { return "index"; //跳转到view视图(index.jsp) }
第二种:ModelAndView
@RequestMapping("/index.html") public ModelAndView toIndex() { //设置视图为hello,装载信息 ModelAndView mav = new ModelAndView("hello","message","Hello,SpringMVC"); return mav; }
第三种:@ResponseBody修饰,用于显示信息
a.只显示字符串信息
@RequestMapping("/show.html") public String showMessage() { return "Hello,SpringMVC"; }
b.显示对象,转换成json
首先需要导入jar包:jackson-core-lgpl-1.9.6.jar和jackson-mapper-lgpl-1.9.6.jar
@RequestMapping("/show.html") public @ResponseBody User showMessage(){ User user = new User(); user.setName("meigesir"); user.setAddress("address"); return user; }
4>接受表单值:
a.save.jsp
<form action="save" method="post"> name:<input name="name" type="text"/><br/> password:<input name="password" type="password""/><br/> zipcode:<input name="zipcode" type="text"/><br/> <input name="submit" type="submit"/> </form>
b. @RequestMapping(value="/save.html",method=RequestMethod.POST)
//其中对象(user)属性会自动装载, public String save(User user,String zipcode){ System.out.println(user.getAddress()); System.out.println("zipCode:" + zipcode); return "redirect:/index.html";//重定向只需要加"redirect:" }
5>使用request、response、session(只需要传进来即可)
@RequestMapping("/show.html") public String methodA(HttpServletRequest request, HttpServletResponse response,HttpSession session){ session.setAttribute("session", "Hello,Session!"); return "hello"; }
可以在hello.jsp页面通过${sessionScope.session }取到值
6>文件上传
首先我们导入jar包:commons-fileupload-1.2.2.jar、commons-io-2.0.1.jar
a.配置文件上传解析器:我们已经在springmvc-servlet.xml配置了“配置文件上传解析器”
b.JSP页面
<form action="file" method="post" enctype="multipart/form-data"> <input type="text" name="name"/> <input type="file" name="file"/> <input type="submit" value="upload"/> </form>
c.服务器端程序
@RequestMapping(value="file",method=RequestMethod.POST) public String file(String name,@RequestParam MultipartFile file){ //上面的@RequestParam代表是从JSP页面传过来的值 System.out.println("文件名:" + name); try { file.transferTo(new File("c:/upload/" + file.getOriginalFilename())); } catch (IOException e) { e.printStackTrace(); } return "file"; }
7>Model ModelAndView
@RequestMapping("/model.html") public String testModel(Model model){ model.addAttribute("message", "model"); return "hello"; }
ModelAndView前面已经详细介绍过
区别就是:Model的返回类型可以是String,ModelAndView返回类型是ModelAndView