10.springboot拦截器实例

项目结构

1.pom.xml文件，自动生成，不进行修改

"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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.7.3version>
        <relativePath/> 
    parent>
    <groupId>com.itgroupId>
    <artifactId>012-springboot-interceptorartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>012-springboot-interceptorname>
    <description>Demo project for Spring Bootdescription>
    <properties>
        <java.version>1.8java.version>
    properties>
    <dependencies>
        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
 
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>
    dependencies>
 
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
            plugin>
        plugins>
    build>
 
project>

2.创建拦截器实现类LoginInterceptor（项目实战中自动返回true或者false，在本例中手动添加为返回true，也就是拦截成功的地址会返回true）

package com.it.web;
 
import org.springframework.web.servlet.HandlerInterceptor;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
/**
 * 自定义拦截器
 */
 
public class LoginInterceptor implements HandlerInterceptor {
 
    /**
     *
     * @param request
     * @param response
     * @param handler  被拦截的控制器对象
     * @return boolean
     *        true:请求可以被Controller处理
     *        false:请求被截断
     * @throws Exception
     */
 
    @Override
    public boolean preHandle(HttpServletRequest request,
                             HttpServletResponse response,
                             Object handler) throws Exception {
        System.out.println("执行了LoginInterceptor的preHandler");
        return true;
    }
}

3.注册拦截器对象，相当于springMVC的配置文件

详细代码

package com.it.config;
 
import com.it.web.LoginInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
import java.util.logging.Handler;
 
@Configuration
public class MyAppConfig implements WebMvcConfigurer {
 
    //添加拦截器对象，注入到容器中
 
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //创建拦截器对象
        HandlerInterceptor interceptor=new LoginInterceptor();
        //指定拦截的请求uri地址
        String path []={"/user/**"};
        //指定不拦截的地址
        String excludePath []={"/user/login"};
        registry.addInterceptor(interceptor)
                .addPathPatterns(path)
                .excludePathPatterns(excludePath);
 
 
    }
}

4.创建控制类BootController类

package com.it.controller;
 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
 
@Controller
public class BootController {
 
    @RequestMapping("/user/account")
    @ResponseBody
    public String userAccount(){
        return "访问user/account地址";
    }
 
    @RequestMapping("/user/login")
    @ResponseBody
    public String userLogin(){
        return "访问user/login地址";
    }
 
}

5.运行Application文件，启动Tomcat进行测试

 

 清空控制台重新访问/user/login地址，如果没有拦截，控制台就不会打印上面的那句话