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[Java教程]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.

 

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:

 

package com.souvc.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 SomeInterceptor implements HandlerInterceptor {  public void afterCompletion(HttpServletRequest req,      HttpServletResponse res, Object handller, Exception e)      throws Exception {    System.out.println("请求处理完成后调用");  }  public void postHandle(HttpServletRequest req, HttpServletResponse res,      Object handller, ModelAndView mv) throws Exception {    System.out.println("处理器执行后调用");  }  public boolean preHandle(HttpServletRequest req, HttpServletResponse res,      Object handller) throws Exception {    System.out.println("处理器执行前调用");    return true;  }}

 

步骤二:修改spring-mvc.

打开工程src下的spring-mvc.

 <mvc:interceptors>    <mvc:interceptor>      <mvc:mapping path="/spring/*"/>      <mvc:exclude-mapping path="/login/*"/>      <bean class="com.souvc.interceptor.SomeInterceptor"/>    </mvc:interceptor>  </mvc:interceptors>

 

spring-mvc.

<?  ="http://www.w3.org/2001/  ="http://www.springframework.org/schema/context"  ="http://www.springframework.org/schema/jdbc"  ="http://www.springframework.org/schema/jee"  ="http://www.springframework.org/schema/tx"  ="http://www.springframework.org/schema/data/jpa"  ="http://www.springframework.org/schema/util"  ="http://www.springframework.org/schema/mvc"  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/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd      http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd      http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd      http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd      http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd      http://www.springframework.org/schema/mvc http://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/*"/>      <bean class="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。

package com.souvc.controller;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;@Controller@RequestMapping("/spring")public class HelloController {  @RequestMapping("/hello.form")  public String execute() throws Exception {    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.

<?  ="http://www.w3.org/2001/  xsi:schemaLocation="http://java.sun.com///java.sun.com/  <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.

 

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