在SpringMVC项目中新建一个简单的拦截器（Interceptor）

深藏阁楼爱情的钟 2022-01-11 06:49 203阅读 0赞

最近要在工作中用到拦截器（Interceptor）,故写一个简单的interceptor

我在springmvc的项目中新建的拦截器，也就是接上一篇《idea 创建 Maven + SpringMVC项目》

[https://blog.csdn.net/liuying1802028915/article/details/90643364][https_blog.csdn.net_liuying1802028915_article_details_90643364]

一。首先我们写了一个 Controller

package com.taoj.controller;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    @Controller
    @RequestMapping("hi")
    public class HelloController {
    
        @RequestMapping("hello")
        @ResponseBody
        public String sayHello(){
            System.out.println("进入Controller的sayHello方法");
            System.out.println("退出Controller的sayHello方法");
            return "jjjjjjjjjjjjjjjj";
        }
    }

二。新建一个

com.taoj.interceptor.InterceptorDemo

package com.taoj.interceptor;
    
    import org.springframework.web.servlet.HandlerInterceptor;
    import org.springframework.web.servlet.ModelAndView;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class InterceptorDemo implements HandlerInterceptor {
        @Override
        public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
            System.out.println("进入preHandle方法");
            return true;
        }
    
        @Override
        public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
            String url = httpServletRequest.getServletPath();//获取当前url
            String contextPath = httpServletRequest.getContextPath();//获取当前项目的根目录
            System.out.println("url:"+url);
            System.out.println("contextPath:"+contextPath);
            System.out.println("进入postHandler 方法");
        }
    
        @Override
        public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
            System.out.println("进入afterCompletion 方法");
    
        }
    }

然后在applicationContext.xml 中 配置该Interceptor

<?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"
           xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
    
        <mvc:interceptors>
            <mvc:interceptor>
                <mvc:mapping path="/**"/>
                <bean id="interceptorDemo" class="com.taoj.interceptor.InterceptorDemo"/>
            </mvc:interceptor>
        </mvc:interceptors>
    
    </beans>

然后启动项目，访问 [http://localhost:8080/mvc/hi/hello.form][http_localhost_8080_mvc_hi_hello.form]

输出为：

进入preHandle方法  
进入Controller的sayHello方法  
退出Controller的sayHello方法  
url:/hi/hello.form  
contextPath:/mvc  
进入postHandler 方法  
进入afterCompletion 方法

由此可见Interceptor的作用

源码见：[https://github.com/taoxiaotao6/springmvcdemo14.git][https_github.com_taoxiaotao6_springmvcdemo14.git]

这一片学习了在springmvc 中 拦截器（Interceptor）的简单使用

不积跬步，无以至千里

不积小流，无以成江海

[https_blog.csdn.net_liuying1802028915_article_details_90643364]: https://blog.csdn.net/liuying1802028915/article/details/90643364
[http_localhost_8080_mvc_hi_hello.form]: http://localhost:8080/mvc/hi/hello.form
[https_github.com_taoxiaotao6_springmvcdemo14.git]: https://github.com/taoxiaotao6/springmvcdemo14.git