Java笔记之SpringMVC(二):项目构建
1.Eclipse新建Dynamic Web Project项目
2.在WebContent下的WEB-INF下的lib文件夹中导入以下jar包,并Build Path
3.打开WebContent下的WEB-INF下的web.xml文件,配置SpringMVC的前端控制器
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1"> <!-- 配置SpringMVC的前端控制器 --> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <!-- 声明SpringMVC配置文件的位置 --> <param-value>classpath:springmvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <!-- 所有以action结尾的请求都交给SpringMVC处理 --> <url-pattern>*.action</url-pattern> </servlet-mapping> <display-name>springmvc_demo</display-name> <welcome-file-list> <welcome-file>/WEB-INF/jsp/index.jsp</welcome-file> </welcome-file-list> </web-app>
4.src目录下新建springmvc.xml文件
<?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:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"> <!-- 方式一:非注解方式 --> <!-- 将welcome.action请求交给com.springmvc.demo.controller.WelcomeController处理 --> <bean name="/welcome.action" class="com.springmvc.demo.controller.WelcomeController"></bean> <!--配置处理器映射器 --> <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"></bean> <!-- 配置处理器适配器 --> <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"></bean> <!-- 配置视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"></property> <property name="suffix" value=".jsp"></property> </bean> </beans>
5.src下新建包com.springmvc.demo.controller,在该包下新建WelcomeController类,实现Controller接口
package com.springmvc.demo.controller; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; public class WelcomeController implements Controller{ @Override public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception { ModelAndView mav=new ModelAndView(); mav.addObject("message", "欢迎您:张三"); mav.setViewName("welcome"); return mav; } }
6.在WebContent下的WEB-INF下新建jsp文件夹,在该文件夹下新建index.jsp和welcome.jsp
index.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>index.jsp</title> </head> <body> <h3>这里是index页面</h3> <a href="welcome.action">欢迎页面</a> </body> </html>
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>欢迎页面</title> </head> <body> <h1>${message }</h1> </body> </html>
7.启动项目,之后点击index.js页面的"欢迎页面"的链接,做welcome.action请求
8.说明
(1).在springmvc.xml中配置了视图解析器的类以及两个配置项prefix和suffix,prefix配置的是视图的前缀,suffix配置的是视图的后缀.
比如,类com.springmvc.demo.controller.WelcomeController中ModelAndView对象中设置的视图名称为welcome,与视图解析器配置的视图前缀和后缀拼接成真正的视图/WEB-INF/jsp/welcome.jsp
(2).使用非注解的方式配置处理器映射器和处理器适配器,这样的话调用的Handler(也就是常说的Controller类)要实现Controller接口,并重写handleRequest方法.
这就突显出了一个缺点:一个Handler只能处理一个请求,请求多的话定义的Handler也就多了,相关的请求也只能放在不同的Handler中.
所以这才有了注解的方式.
