spring mvc helloworld

Spring学习笔记——Spring MVC的简单实例

开发环境：MyEclipse，Spring2.0

(1)新建一个WebProject,命名为myApp，导入所需要的jar包：

在工程名上点右键-->BuildPath-->ConfigureBuildPath-->Libraries-->Add External Jars，导入spring.jar，commons-logging.jar,log4j-1.2.9.jar这3个包。（好像在Spring3.0以上的版本中，就没有spring.jar这个包了，取而代之的是一些分开的小包）。

(2)修改WEB-INF目录下web.xml文件，内容如下

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<? 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" > < welcome-file-list > < welcome-file > index.jsp </ welcome-file > </ welcome-file-list > < servlet > < servlet-name > dispatcherServlet </ servlet-name > < servlet-class > org.springframework.web.servlet.DispatcherServlet </ servlet-class > <!-- 初始化参数 --> <!-- <init-param> <param-name>contextConfigLocation</param-name> <param-value>dispatcherServlet-servlet.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> --> </ servlet > <!-- 拦截所有以do结尾的请求 --> < servlet-mapping > < servlet-name > dispatcherServlet </ servlet-name > < url-pattern > *.do </ url-pattern > </ servlet-mapping > </ web-app >

(3)编写实现输出的JSP页面index.jsp，放在WebRoot目录下

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<% @ page language = " java " import = " java.util.* " pageEncoding = " UTF-8 " %> < html > < head >< title > 第一个SpringMVC实例 </ title ></ head > <% String str = ( String )request.getAttribute( " helloWorld " ); %> < body > < H1 > <% = str %> </ H1 > </ body > </ html >

(4)编写控制器HelloWorldAction.java，放在src目录下的com.jp.action包里

在Spring里，所有控制器最终都可以看作是实现了Controller接口。下面代码中的handleRequest（）方法返回一个ModelAndView，用来显示返回的页面和页面上的内容

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package com.jp.action; import java.util.HashMap; import java.util.Map; import java.util.logging.Logger; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; // 实现了Controller接口,需要在导入spring.jar包 public class HelloWorldAction implements Controller{ private Logger logger = Logger.getLogger( this .getClass().getName()); private String helloWorld; private String viewPage; public String getHelloWorld() { return helloWorld; } public void setHelloWorld(String helloWorld) { this .helloWorld = helloWorld; } public String getViewPage() { return viewPage; } public void setViewPage(String viewPage) { this .viewPage = viewPage; } // 实现Controller接口中的handleRequest方法 public ModelAndView handleRequest(HttpServletRequest req, HttpServletResponse res) throws Exception { // TODO Auto-generated method stub Map model = new HashMap(); model.put( " helloWorld " ,getHelloWorld()); return new ModelAndView(getViewPage(),model); } }

(5)配置Spring文档dispatcherServlet-servlet.xml，放在WEB-INF目录下

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<? xml version="1.0" encoding="UTF-8" ?> <! DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd" > < beans > <!-- 定义映射 --> < bean id ="urlMapping" class ="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping" > < property name ="mappings" > < props > < prop key ="helloWorld.do" > helloWorldAction </ prop > </ props > </ property > </ bean > <!-- 定义视图 --> < bean id ="viewResolver" class ="org.springframework.web.servlet.view.InternalResourceViewResolver" > < property name ="viewClass" > < value > org.springframework.web.servlet.view.InternalResourceView </ value > </ property > </ bean > <!-- 定义控制器 --> < bean id ="helloWorldAction" class ="com.jp.action.HelloWorldAction" > < property name ="helloWorld" > < value > Good Luck! </ value > </ property > < property name ="viewPage" > < value > /index.jsp </ value > </ property > </ bean > </ beans >

然后，将项目部署到Tomcat，在浏览器地址栏里输入http://localhost:8080/myApp/helloWorld.do,即可看到下面的界面