1 自定义拦截器

下方的redisOperator就是个工具类，对redis api 操作进行简单的封装，如果有兴趣的，可以下方的地址下载：

CSDN下载地址： https://download.csdn.net/download/qq_15769939/15378282

import com.auskat.utils.JsonUtils;
import com.auskat.utils.R;
import com.auskat.utils.RedisOperator;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
import java.util.Objects;

/**
 * 类文件: UserTokenInterceptor
 * <p>
 * <p>
 * 类描述：用户请求拦截器
 * <p>
 * 作     者： AusKa_T
 * <p>
 * 日     期： 2021/2/19 0019
 * <p>
 * 时     间： 22:08
 * <p>
 */
public class UserTokenInterceptor implements HandlerInterceptor {

    public static final String REDIS_USER_TOKEN = "redis_user_token";

    @Autowired
    private RedisOperator redisOperator;

    /**
     * 拦截请求，在访问controller请求之前
     * headerUserId  headerUserToken
     * @param request 请求
     * @param response 响应
     * @param handler 拦截
     * @return 返回结果
     * @throws Exception 异常
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

//        System.out.println("进入到拦截器被拦截...");

        String userToken = request.getHeader("headerUserToken");
        String userId = request.getHeader("headerUserId");

        if (StringUtils.isNotBlank(userId) && StringUtils.isNotBlank(userToken)) {
            String uniqueToken = redisOperator.get(REDIS_USER_TOKEN + ":" + userId);
            if (StringUtils.isBlank(uniqueToken)) {
                returnErrorResponse(response, R.errorMsg("请登录..."));
                return false;
            } else {
                if (!uniqueToken.equals(userToken)) {
                    returnErrorResponse(response, R.errorMsg("账号在异地登录..."));
                    return false;
                }
            }
        } else {
            returnErrorResponse(response, R.errorMsg("请登录..."));
            return false;
        }
        /*
         * false: 请求被拦截，被驳回，验证出现问题
         * true: 请求在经过验证之后，是OK的，可以放行
         */
        return true;
    }

    /**
     * 处理异常返回信息
     * @param response 响应
     * @param result 结果
     */
    public void returnErrorResponse(HttpServletResponse response, R result) {
        OutputStream out = null;

        try {
            response.setCharacterEncoding("utf-8");
            response.setContentType("text/json");
            out = response.getOutputStream();
            out.write(Objects.requireNonNull(JsonUtils.objectToJson(result)).getBytes(StandardCharsets.UTF_8));
            out.flush();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    /**
     * 请求访问Controller之后，渲染视图之前
     * @param request 请求
     * @param response 响应
     * @param handler 拦截
     * @param modelAndView 视图
     * @throws Exception 异常
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    /**
     * 拦截请求，在访问controller请求之后，渲染视图之后
     * @param request 请求
     * @param response 响应
     * @param handler 拦截
     * @throws Exception 异常
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }

2 注册拦截器

import com.auskat.controller.interceptor.UserTokenInterceptor;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * 类文件: WebMvcConfig
 * <p>
 * <p>
 * 类描述：
 * <p>
 * 作     者： AusKa_T
 * <p>
 * 日     期： 2020/11/25 0025
 * <p>
 * 时     间： 13:27
 * <p>
 */
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Bean
    public RestTemplate restTemplate(RestTemplateBuilder builder) {
        return builder.build();
    }

    @Bean
    public UserTokenInterceptor userTokenInterceptor() {
        return new UserTokenInterceptor();
    }

    /**
     * 注册拦截器
     * @param registry 注册器
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(userTokenInterceptor())
                .addPathPatterns("/**")
                    .excludePathPatterns("/admin/**");
        WebMvcConfigurer.super.addInterceptors(registry);
    }
}