code: /*
   * 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 org.apache.skywalking.e2e.controller;
  
  import com.google.common.base.Strings;
  import lombok.RequiredArgsConstructor;
  import org.apache.skywalking.apm.toolkit.trace.TraceContext;
  import org.apache.skywalking.e2e.E2EConfiguration;
  import org.apache.skywalking.e2e.User;
  import org.springframework.http.ResponseEntity;
  import org.springframework.web.bind.annotation.PostMapping;
  import org.springframework.web.bind.annotation.RequestBody;
  import org.springframework.web.bind.annotation.RestController;
  import org.springframework.web.client.RestTemplate;
  
  import java.util.Optional;
  import java.util.Random;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  @RestController
  @RequiredArgsConstructor
  public class UserController {
      private final RestTemplate restTemplate = new RestTemplate();
  
      private final E2EConfiguration configuration;
  
      private final int sleepMin = 500;
  
      private final int sleepMax = 1000;
  
      @PostMapping("/info")
      public String info() throws InterruptedException {
          Thread.sleep(randomSleepLong(sleepMin, sleepMax));
  
          Optional<ResponseEntity<String>> optionalResponseEntity = Stream.of(
              Strings.nullToEmpty(configuration.getProviderBaseUrl()).split(","))
                                                                          .map(baseUrl -> restTemplate.postForEntity(
                                                                              baseUrl + "/info", null, String.class))
                                                                          .findFirst();
          if (optionalResponseEntity.isPresent() && optionalResponseEntity.get().getStatusCodeValue() == 200) {
              return optionalResponseEntity.get().getBody();
          }
          throw new RuntimeException();
      }
  
      @PostMapping("/users")
      public Object createAuthor(@RequestBody final User user) throws InterruptedException {
          Thread.sleep(randomSleepLong(sleepMin, sleepMax));
  
          return Stream.of(Strings.nullToEmpty(configuration.getProviderBaseUrl()).split(","))
                       .map(baseUrl -> restTemplate.postForEntity(baseUrl + "/users", user, User.class))
                       .collect(Collectors.toList());
      }
  
      @PostMapping("/correlation")
      public String correlation() throws InterruptedException {
          Thread.sleep(randomSleepLong(sleepMin, sleepMax));
          TraceContext.putCorrelation("CONSUMER_KEY", "consumer");
  
          String baseUrl = configuration.getProviderBaseUrl();
          ResponseEntity<String> resp = restTemplate.postForEntity(baseUrl + "/correlation", null, String.class);
          return resp.getBody();
      }
  
      private long randomSleepLong(int min, int max) {
          Random rand = new Random();
          int randomNumber = rand.nextInt((max - min) + 1) + min;
          return randomNumber;
      }
  }
  