1 概述
- SpringMVC可以使用兰机器对请求进行拦截处理，用户可以自定义拦截器来实现特定的功能，自定义的拦截器必须HandlerInterceptor接口。
- HandlerInterceptor接口的定义如下：
package org.springframework.web.servlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.lang.Nullable;
import org.springframework.web.method.HandlerMethod;
public interface HandlerInterceptor {
/**
* 这个方法在业务处理器处理请求之前被调用，在该方法中对用户请求进行处理。如果程序员决定拦截器对请求拦截处理后
* 还要调用其他拦截器，或者是业务处理器去进行处理，则返回true；如果程序员决定不需要再调用其他的组件去处理请求，
* 则返回false。
*/
default boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
return true;
}
/**
* 这个方法在业务处理器处理完请求后，但是DispaterServlet向客户端返回响应前被调用
*
*
*/
default void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
@Nullable ModelAndView modelAndView) throws Exception {
}
/**
* 这个方法在DispatcherServlet完全处理完请求后被带哦用，可以在该方案分中进行一些资源清理操作
*
*/
default void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,
@Nullable Exception ex) throws Exception {
}
}
2 入门示例
2.1 index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<a href="${pageContext.request.contextPath}/test">test</a>
<a href="${pageContext.request.contextPath}/emp">emp</a>
</body>
</html>
2.2 FirstInterceptor.java
package com.sunxiaping.springmvc.controller;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class FirstInceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("-------------FirstInceptor-------preHandle--");
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
System.out.println("-------------FirstInceptor-------postHandle--");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
System.out.println("-------------FirstInceptor-------afterCompletion--");
}
}
2.3 SecondInterceptor.java
package com.sunxiaping.springmvc.controller;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class SecondInceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("-------------SecondInceptor-------preHandle--");
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
System.out.println("-------------SecondInceptor-------postHandle--");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
System.out.println("-------------SecondInceptor-------afterCompletion--");
}
}
2.4 TestController.java
package com.sunxiaping.springmvc.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class TestController {
@RequestMapping(value = "/test")
public String test(){
return "success";
}
@RequestMapping(value = "/emp")
public String emp(){
return "success";
}
}
2.5 SpringMVC.xml
<?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"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd ">
<!-- 配置自动扫描的包 -->
<context:component-scan base-package="com.sunxiaping.springmvc"></context:component-scan>
<!-- 配置视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<mvc:interceptors>
<!-- 拦截所有资源 -->
<bean class="com.sunxiaping.springmvc.controller.FirstInceptor"></bean>
<!-- 拦截指定资源 -->
<mvc:interceptor>
<mvc:mapping path="/emp"/>
<bean class="com.sunxiaping.springmvc.controller.SecondInceptor"/>
</mvc:interceptor>
</mvc:interceptors>
<mvc:annotation-driven></mvc:annotation-driven>
</beans>
2.6 success.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
成功啦 <br/>
</body>
</html>
