搭建环境

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>Spring_mvc</display-name>
 
  <!-- springmvc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>
      <!-- 指定加载的springmvc框架配置文件
      默认命名方式：servlet的name+‘-servlet.xml‘，即springmvc-servlet.xml，此文件默认在/WEB-INF/下
       -->
      <param-value>classpath:springmvc.xml</param-value>
    </init-param>
      
  </servlet>
  <servlet-mapping>
      <servlet-name>springmvc</servlet-name>
      <url-pattern>*.action</url-pattern>
  </servlet-mapping>
 
 <!-- post乱码过虑器 -->
 <filter>
    <filter-name>CharacterEncodingFilter</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>CharacterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
 
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

public class HelloWorld implements Controller {
    @Override
    public ModelAndView handleRequest(HttpServletRequest request,
            HttpServletResponse response) throws Exception {

        ModelAndView modelAndView = new ModelAndView();
        String message = "hello world!!!";
        modelAndView.addObject("message", message);
        modelAndView.setViewName("helloworld");
        return modelAndView;
    }
}