spring mvc即mvc拦截器实例（2）

晨曦

2011-02-15

控制器java代码

package springapp.web;

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

//声明为servlet控制器
@Controller
public class HelloWorld
{
    
    //访问地址为</hellowor.htm?name=aaaaaaaaa》,@RequestParam("name") String username为接收的参数
    @RequestMapping("/hellowor")
    public String hi(HttpServletRequest request,
            @RequestParam("name") String username)
    {
        System.out.println(username);
        //设置request范围变量，页面可以获取
        request.setAttribute("now", "fdsafdsfdsfdsfds");
        //跳转到WEB-INF/hello.jsp页面
        return "WEB-INF/hello";
    }
    
  //访问地址为</hii.htm，htm在web.xml中的配置
    @RequestMapping("/hii")
    public String hii()
    {
        //跳转到/hello.jsp页面,路径配置在springapp-servlet.xml配置路径地址的前缀和后缀
        /*<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" 
            p:prefix="/" p:suffix=".jsp"/>*/
        return "hello";
    }
}

mvc拦截器java代码

package springapp.web;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

//定义拦截器
public class MyInterceptor implements HandlerInterceptor
{
    
    public void afterCompletion(HttpServletRequest arg0,
            HttpServletResponse arg1, Object arg2, Exception arg3)
            throws Exception
    {
        System.out.println("视图已处理完后执行的方法，通常用于释放资源；");
        
    }
    
    public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,
            Object arg2, ModelAndView arg3) throws Exception
    {
        System.out.println("控制器的方法已经执行完毕，转换成视图之前的处理；");
        
    }
    
    public boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1,
            Object arg2) throws Exception
    {
        System.out
                .println("拦截器的前端，执行控制器之前所要处理的方法，通常用于权限控制、日志，其中，Object arg2表示下一个拦截器；");
        return true;
    }
    
}

jsp代码

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jstl/fmt" %>
<!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>Insert title here</title>
</head>
<body>
<h1>Hello - Spring Application</h1>
    <p>Greetings.WEBINF</p>
	<%=request.getAttribute("now") %>
	<h1><fmt:message key="spring.hello"/></h1>
</body>
</html>

spring拦截器