Spring自定义一个拦截器类SomeInterceptor，实现HandlerInterceptor接口及其方法的实例
利用SPRing的拦截器可以在处理器Controller方法执行前和后增加逻辑代码，了解拦截器中preHandle、postHandle和afterCompletion方法执行时机。
自定义一个拦截器类SomeInterceptor，实现HandlerInterceptor接口及其方法。
然后在spring-mvc.xml中添加拦截器配置，来指定拦截哪些请求。
步骤一： 创建SomeInterceptor拦截器组件
新建一个com.souvc.interceptor包，在该包中新建一个SomeInterceptor类。SomeInterceptor类要实现HandlerInterceptor接口及其约定方法，代码如下：
packagecom.souvc.interceptor;importjavax.servlet.http.HttpServletRequest;importjavax.servlet.http.HttpServletResponse;importorg.springframework.web.servlet.HandlerInterceptor;importorg.springframework.web.servlet.ModelAndView;publicclassSomeInterceptorimplementsHandlerInterceptor {publicvoidafterCompletion(HttpServletRequest req,
HttpServletResponse res, Object handller, Exception e)throwsException {
System.out.println("请求处理完成后调用");
}publicvoidpostHandle(HttpServletRequest req, HttpServletResponse res,
Object handller, ModelAndView mv)throwsException {
System.out.println("处理器执行后调用");
}publicbooleanpreHandle(HttpServletRequest req, HttpServletResponse res,
Object handller)throwsException {
System.out.println("处理器执行前调用");returntrue;
}
}
步骤二：修改spring-mvc.xml配置
打开工程src下的spring-mvc.xml文件，追加SomeInterceptor配置。
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/spring/*"/>
<mvc:exclude-mapping path="/login/*"/>
<beanclass="com.souvc.interceptor.SomeInterceptor"/>
</mvc:interceptor>
</mvc:interceptors>
spring-mvc.xml源码：
<?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:jdbc="http://www.springframework.org/schema/jdbc"xmlns:jee="http://www.springframework.org/schema/jee"xmlns:tx="http://www.springframework.org/schema/tx"xmlns:jpa="http://www.springframework.org/schema/data/jpa"xmlns:util="http://www.springframework.org/schema/util"xmlns:mvc="http://www.springframework.org/schema/mvc"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans-3.2.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context-3.2.xsdhttp://www.springframework.org/schema/jdbchttp://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsdhttp://www.springframework.org/schema/jeehttp://www.springframework.org/schema/jee/spring-jee-3.2.xsdhttp://www.springframework.org/schema/txhttp://www.springframework.org/schema/tx/spring-tx-3.2.xsdhttp://www.springframework.org/schema/data/jpahttp://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsdhttp://www.springframework.org/schema/utilhttp://www.springframework.org/schema/util/spring-util-3.2.xsdhttp://www.springframework.org/schema/mvchttp://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd"><util:properties id="jdbcProps" location="classpath:db.properties" />
<context:component-scan base-package="com.souvc" />
<!-- 视图处理 -->
<bean id="viewResolver"class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/spring/*"/>
<mvc:exclude-mapping path="/login/*"/>
<beanclass="com.souvc.interceptor.SomeInterceptor"/>
</mvc:interceptor>
</mvc:interceptors>
</beans>
步骤三： 创建控制器HelloController中添加控制台打印信息
创建HelloController,在execute方法增加控制台打印语句。
packagecom.souvc.controller;importorg.springframework.stereotype.Controller;importorg.springframework.web.bind.annotation.RequestMapping;
@Controller
@RequestMapping("/spring")publicclassHelloController {
@RequestMapping("/hello.form")publicString execute()throwsException {
System.out.println("执行HelloController");return"hello";
}
}
在WebRoot目录下的jsp目录下添加hello.jsp页面：
<%@ page language="java"import="java.util.*" pageEncoding="utf-8"%>
<%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 'hello.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>hello<br>
</body>
</html>
web.xml文件如下：
<?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"><welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>*.form</url-pattern>
</servlet-mapping>
</web-app>
步骤四：部署并访问工程
部署工程后启动Tomcat，在浏览器中输入地址http://localhost:8080/SpringValues/spring/hello.form，观察控制台输出结果。
处理器执行前调用
执行HelloController
处理器执行后调用
请求处理完成后调用