拦截器继承org.springframework.web.servlet.HandlerInterceptor接口
自定义拦截器继承 HandlerInterceptor,根据需要重写 preHandle , postHandle ,afterCompletion这3个方法。
这3个拦截器执行过程参考下图
过滤器、拦截器 流程图
流程图来自 https://www.cnblogs.com/jeffwongishandsome/p/spring-boot-use-filter-and-interceptor-to-implement-an-easy-auth-system.html
由上面拦截器在一个web请求过程中处理流程可知,要想在一个请求controller之前处理关心的拦截信息,需要在preHandle方法中处理.
测试源码
下面 demo,通过 自定义拦截器中 拒绝 用户名为 ‘zhangsan’ 的请求
springboot 项目interceptor_demo 的目录结构如下:
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.6.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>interceptor_demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>interceptor_demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
配置文件application.properties,只配置web server 端口
server.port=8089
自定义拦截器 TestInterceptor
package com.example.interceptor_demo.interceptor;import org.springframework.stereotype.Component;import org.springframework.web.servlet.HandlerInterceptor;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.PrintWriter;@ComponentpublicclassTestInterceptorimplementsHandlerInterceptor{@OverridepublicbooleanpreHandle(HttpServletRequest request, HttpServletResponse response, Object handler)throws Exception{
String name= request.getParameter("name");if("zhangsan".equals(name)){//拒绝zhangsan的请求
response.setCharacterEncoding("utf-8");
response.setContentType("application/json; charset=utf-8");
response.setStatus(403);
PrintWriter writer= response.getWriter();
writer.write("静止访问");//false 表示这个处理不再往下执行,不会进入controllerreturnfalse;}//true 继续往下执行 进入controllerreturntrue;}}
注册拦截器 WebConfigurer
package com.example.interceptor_demo.interceptor;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.InterceptorRegistry;import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;@ConfigurationpublicclassWebConfigurerimplementsWebMvcConfigurer{@Autowiredprivate TestInterceptor loginInterceptor;/**
* 这个方法是用来配置静态资源的,比如html,js,css,等等
*/@OverridepublicvoidaddResourceHandlers(ResourceHandlerRegistry registry){}/**
* 这个方法用来注册拦截器,我们自己写好的拦截器需要通过这里添加注册才能生效
* @param registry
*/@OverridepublicvoidaddInterceptors(InterceptorRegistry registry){// addPathPatterns("/**") 表示拦截所有的请求,// addPathPatterns("/test/**") 表示拦截/test/ 下的所有路径请求,// addPathPatterns("/test/*") 表示拦截/test/abc,拦截/test/aaa , 不拦截 /test/abc/def// addPathPatterns("/test/**").excludePathPatterns("/test/login", "/test/register") 表示拦截/test/ 下的所有路径请求,但不拦截 /test/login 和 /test/register
registry.addInterceptor(loginInterceptor).addPathPatterns("/test");}}
测试类 TestController
package com.example.interceptor_demo.controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;@RestControllerpublicclassTestController{@RequestMapping("/test")public Stringtest(){return"access success";}}
启动类 InterceptorDemoApplication
package com.example.interceptor_demo;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.context.annotation.Configuration;@SpringBootApplicationpublicclassInterceptorDemoApplication{publicstaticvoidmain(String[] args){
SpringApplication.run(InterceptorDemoApplication.class, args);}}
测试
启动后,浏览器输入 127.0.0.1:8089/test?name=zhangsan
浏览器输入 127.0.0.1:8089/test?name=lisi
源码
链接:https://pan.baidu.com/s/183h87UI4S3OpRjWBNdBJPA
提取码:20o1
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