SpringMVC -- 梗概--源码--贰--拦截器：Interceptor

附：实体类

1.配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <display-name></display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>

<!-- 前端控制器
/=默认的url-pattern
/a/b/c  /a

/a/d/c
/a/d
/a
/
*注意：此控制器默认加载/WEB-INF下的xxx-servlet.xml文件
：其中xxx等于【DispatcherServlet的配置名】
-->
<servlet>
<servlet-name>mvc62</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:mvc62.xml</param-value>
</init-param>
<!-- 随项目启动而启动 -->
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>mvc62</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>

<!-- 专治Post请求参数乱码 -->
<filter>
<filter-name>encoding62</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<!-- 将请求的编码方式设置为utf-8 -->
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encoding62</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>

2.配置SpringMVC.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- xmlns:xml name space 是每一个schema唯一标识 -->
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd"> 
<!-- 扫描所有控制器中的注解 -->
<context:component-scan base-package="com.c61.controller"></context:component-scan>
<!--
MVC中基于注解开发，导入注解驱动
<mvc:annotation-driven/>
-->
<mvc:annotation-driven>
<mvc:message-converters>
<bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<!-- 支持的格式：application/json -->
<value>application/json</value>
</list>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
<!-- 视图解析器：解析视图
控制器方法的返回值，会被视图解析器捕获。"abc"
根据捕获的内容，解析出一个视图地址:/abc.jsp
-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<!--
静态资源：html,js,css,jpg
访问404 解决
-->
<mvc:default-servlet-handler/>

<!-- 声明异常处理器 -->
<bean class="com.c61.ex.resolver.MyExceptionResolver"></bean>

<!-- 拦截器配置 -->
<!--
/a/b
inter1
inter2
拦截顺序：先配置先拦截
具体顺序：pre1==pre2==contorller==post2==post1==after2==after1
-->
<mvc:interceptors>
<mvc:interceptor>
<!-- 定义要拦截的路径
/inter/*  匹配   /inter/a   /inter/b    inter/cssdafasfsafs
不能匹配/inter/a/b
/inter/** 匹配 /inter/a  /inter/xxsjaflsajf   /inter/a/b/c/e/d/xxxcvx
*注意：exclude-mapping不能单独使用。要配合mapping使用
：在mapping匹配的范围中排除一些个。
-->
<mvc:mapping path="/inter/**"/>
<mvc:mapping path="/a/b"/>
<mvc:mapping path="/c/**"/>
<mvc:exclude-mapping path="/inter/test/*"/>
<mvc:exclude-mapping path="/c/b/**"/>
<!-- 声明拦截器 -->
<bean class="com.c61.interceptor.MyInterceptor"/>
</mvc:interceptor>
<mvc:interceptor>
<!-- 定义要拦截的路径 -->
<mvc:mapping path="/inter/test"/>
<!-- 声明拦截器 -->
<bean class="com.c61.interceptor.MyInterceptor2"/>
</mvc:interceptor>
</mvc:interceptors>
<!-- 声明文件上传解析器
注意：此解析器，id必须为：multipartResolver
-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 最大允许的上传大小    byte -->
<property name="MaxUploadSize" value="2097152"></property>
</bean>
<!--
注册，验证码生成器
-->
<bean id="captcha" class="com.google.code.kaptcha.servlet.KaptchaExtend">
<constructor-arg>
<props>
<!-- 是否有边框 边框颜色 边框粗细 -->
<prop key="kaptcha.border">no</prop>
<prop key="kaptcha.border.color">105,179,90</prop>
<prop key="kaptcha.border.thickness">20</prop>
<prop key="kaptcha.textproducer.font.color">black</prop>
<prop key="kaptcha.image.width">200</prop>
<prop key="kaptcha.image.height">50</prop>
<prop key="kaptcha.textproducer.font.size">40</prop>
<prop key="kaptcha.session.key">code61</prop>
<prop key="kaptcha.textproducer.char.length">4</prop>
<prop key="kaptcha.textproducer.font.names">Arial,Courier</prop>
<!--   <prop key="kaptcha.background.clear.from">black</prop>
<prop key="kaptcha.background.clear.to">255,0,0</prop>  -->
</props>
</constructor-arg>
</bean>
</beans>

3.配置控制器

package com.c61.controller;

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

import com.c61.service.UserService;
import com.c61.service.UserServiceImpl;

@Controller
@RequestMapping("/inter")
public class InterceptorController {
@RequestMapping("/test")
public String testInter(){
System.out.println("Controller testAAA");
return "forward:/index.jsp";
}
@RequestMapping("/test/b")
public String testInter2(){
System.out.println("Controller testBBB");
return "forward:/index.jsp";
}
@RequestMapping("/test/c/e/f")
public String testInter3(){
System.out.println("Controller testCCC");
return "forward:/index.jsp";
}
}

4.配置拦截器

Class ： MyInterceptor

package com.c61.interceptor;

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

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

public class MyInterceptor implements HandlerInterceptor{

/**
* 在Controller之前执行(常用)
* 抽取Controller中的冗余功能
*/
public boolean preHandle(HttpServletRequest req, HttpServletResponse res,
Object handler) throws Exception {
System.out.println("pre Handle");
//return false;//中断请求，则后续的controller，postHandle...都不在执行
//return true;//请求继续
return true;
}
/**
* 在Controller之后，在响应之前，执行(了解)
* 可以做视图和数据的最终定制
*
*/
public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,
Object arg2, ModelAndView mav) throws Exception {
System.out.println("post Handle");
}
/**
* 在视图渲染完毕后执行(了解)
* 资源回收
*/
public void afterCompletion(HttpServletRequest req,
HttpServletResponse res, Object handler, Exception ex)
throws Exception {
System.out.println("after Comletion");
}

}

Class ： MyInterceptor2

package com.c61.interceptor;

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

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

public class MyInterceptor2 implements HandlerInterceptor{

/**
* 在Controller之前执行(常用)
* 抽取Controller中的冗余功能
*/
public boolean preHandle(HttpServletRequest req, HttpServletResponse res,
Object handler) throws Exception {
System.out.println("pre Handle222");
//return false;//中断请求，则后续的controller，postHandle...都不在执行
//return true;//请求继续
String path=req.getContextPath();
res.sendRedirect(path+"/index.jsp");
return false;
}
/**
* 在Controller之后，在响应之前，执行(了解)
* 可以做视图和数据的最终定制
*
*/
public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,
Object arg2, ModelAndView mav) throws Exception {
System.out.println("post Handle222");
}
/**
* 在视图渲染完毕后执行(了解)
* 资源回收
*/
public void afterCompletion(HttpServletRequest req,
HttpServletResponse res, Object handler, Exception ex)
throws Exception {
System.out.println("after Comletion222");
}

}

5.配置视图

View ： index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>

<body>
<img height="100px" width="100px" src="${pageContext.request.contextPath}/up61/${requestScope.name}"/>
</body>
</html>

Client : inter/test



Console :



Client :



Client : inter/test/b



Console :



Client :



Client : inter/test/c/e/f



Console :



Client :

1 定制

public class MyInterceptor implements HandlerInterceptor{
/**
* 在Controller之前执行(常用)
* 抽取Controller中的冗余功能
*/
public boolean preHandle(HttpServletRequest req, HttpServletResponse res,
Object handler) throws Exception {
//return false;//中断请求，则后续的controller，postHandle...都不再执行
//return true;//请求继续
if(xxx){
String path=req.getContextPath();
res.sendRedirect(path+"/index.jsp");//中断之前设置错误视图
return false;
}
return true
}
/**
* 在Controller之后，在响应之前，执行(了解)
* 可以做视图和数据的最终定制
*/
public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,
Object arg2, ModelAndView mav) throws Exception {
}
/**
* 在视图渲染完毕后执行(了解)
* 资源回收
*/
public void afterCompletion(HttpServletRequest req,
HttpServletResponse res, Object handler, Exception ex)
throws Exception {
}
}

2 配置

<mvc:interceptors>
<mvc:interceptor>
<!-- 定义要拦截的路径 -->
<mvc:mapping path="/inter/test"/>
<mvc:mapping path="/inter/a"/>
<mvc:mapping path="/inter/b"/>
<!-- 声明拦截器 -->
<bean class="com.c61.interceptor.MyInterceptor"/>
</mvc:interceptor>
<mvc:interceptor>
<!-- 定义要拦截的路径 -->
<mvc:mapping path="/inter/**"/>
<mvc:exclude-mapping path="/inter/test/**"/>
<!-- 声明拦截器 -->
<bean class="com.c61.interceptor.MyInterceptor2"/>
</mvc:interceptor>
</mvc:interceptors>
*注意：
1>当有多个拦截器同时拦截时，先配置的先拦截。如过Controller1 先后被inter1和inter2拦截，则具体的拦截路程为：
pre1==pre2==contorller==post2==post1==after2==after1
2>/* 只能匹配一级路径：/a  /b  /c  /xxxxxx
.     却不能匹配：/a/b  /e/d/c
/** 能匹配任意多级路径：/a  /b  /a/b/c  /xxs/xxx/xxx/xx
3>mvc:exclude-mapping 不能单独使用，必须配合 mvc:mapping 使用
.     作用是在mvc:mapping的基础上排除一些路径

啦啦啦