package interceptor;
import java.util.Date;

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

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

public class IndexInterceptor extends HandlerInterceptorAdapter {  

	 /**  
     * 在业务处理器处理请求之前被调用  
     * 如果返回false  
     *     从当前的拦截器往回执行所有拦截器的afterCompletion(),再退出拦截器链 
     * 如果返回true  
     *    执行下一个拦截器,直到所有的拦截器都执行完毕  
     *    再执行被拦截的Controller  
     *    然后进入拦截器链,  
     *    从最后一个拦截器往回执行所有的postHandle()  
     *    接着再从最后一个拦截器往回执行所有的afterCompletion()  
     */    
    public boolean preHandle(HttpServletRequest request,    
            HttpServletResponse response, Object handler) throws Exception {
    	
        System.out.println("preHandle(), 在访问Controller之前被调用");  
        return true;
        
    }  

    /** 
     * 在业务处理器处理请求执行完成后,生成视图之前执行的动作    
     * 可在modelAndView中加入数据，比如当前时间 
     */  
    
    public void postHandle(HttpServletRequest request,    
            HttpServletResponse response, Object handler,    
            ModelAndView modelAndView) throws Exception {  
    	System.out.println("postHandle(), 在访问Controller之后，访问视图之前被调用,这里可以注入一个时间到modelAndView中，用于后续视图显示");
    	modelAndView.addObject("date","由拦截器生成的时间:" + new Date());
    }  

    /**  
     * 在DispatcherServlet完全处理完请求后被调用,可用于清理资源等   
     *   
     * 当有拦截器抛出异常时,会从当前拦截器往回执行所有的拦截器的afterCompletion()  
     */ 
    
    public void afterCompletion(HttpServletRequest request,    
            HttpServletResponse response, Object handler, Exception ex)  
    throws Exception {  
          
        System.out.println("afterCompletion(), 在访问视图之后被调用");  
    }  
      
} 

<?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:context="http://www.springframework.org/schema/context"  
    xmlns:mvc="http://www.springframework.org/schema/mvc"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans  
     http://www.springframework.org/schema/beans/spring-beans-3.0.xsd  
     http://www.springframework.org/schema/context  
     http://www.springframework.org/schema/context/spring-context-3.0.xsd  
     http://www.springframework.org/schema/mvc  
     http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"> 
	<bean id="viewResolver"
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/page/" />
		<property name="suffix" value=".jsp" />
	</bean>

	<bean id="simpleUrlHandlerMapping"
		class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
		<property name="mappings">
			<props>
				<prop key="/index">indexController</prop>
			</props>
		</property>
	</bean>
	<bean id="indexController" class="controller.IndexController"></bean>
	<mvc:interceptors>    
	    <mvc:interceptor>    
	        <mvc:mapping path="/index"/>  
	        <!-- 定义在mvc:interceptor下面的表示是对特定的请求才进行拦截的 -->  
	        <bean class="interceptor.IndexInterceptor"/>      
	    </mvc:interceptor>  
	    <!-- 当设置多个拦截器时，先按顺序调用preHandle方法，然后逆序调用每个拦截器的postHandle和afterCompletion方法 -->  
	</mvc:interceptors> 
		
</beans>

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8" isELIgnored="false"%>

<h1>${message}</h1>

<p>${date}</p>