content: /*
   *
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  
  package com.alibaba.cloudapp.microservice.aliyun.demo;
  
  import com.alibaba.cloudapp.api.microservice.TrafficService;
  import io.opentelemetry.context.Scope;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  import org.springframework.cloud.client.loadbalancer.LoadBalanced;
  import org.springframework.context.annotation.Bean;
  import org.springframework.web.bind.annotation.GetMapping;
  import org.springframework.web.bind.annotation.PathVariable;
  import org.springframework.web.bind.annotation.RestController;
  import org.springframework.web.client.RestTemplate;
  
  import javax.servlet.http.HttpServletRequest;
  
  @SpringBootApplication
  public class DemoApplication {
      private static final Logger logger = LoggerFactory.getLogger(DemoApplication.class);
  
      @Autowired
      TrafficService trafficService;
  
      public static void main(String[] args) {
          SpringApplication.run(DemoApplication.class, args);
      }
  
      @Bean
      @LoadBalanced
      RestTemplate restTemplate() {
          return new RestTemplate();
      }
  
      @RestController
      class AController {
  
          @GetMapping("/{tag}")
          public String tag(HttpServletRequest request,
                            @PathVariable String tag) {
              if (tag == null || tag.isEmpty()) {
                  return "";
              }
              logger.info("traffic label before inject: {}", trafficService.getCurrentTrafficLabel());
              try (Scope ignored = trafficService.withTrafficLabel(tag)){
                  logger.info("traffic label after inject: {}", trafficService.getCurrentTrafficLabel());
              }
              return tag;
          }
      }
  }
  