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.oap.server.network.trace.proto;
  
  import io.grpc.ManagedChannel;
  import io.grpc.ManagedChannelBuilder;
  import io.grpc.Status;
  import io.grpc.StatusRuntimeException;
  import io.grpc.internal.DnsNameResolverProvider;
  import io.grpc.netty.NettyChannelBuilder;
  import io.grpc.stub.StreamObserver;
  import org.apache.skywalking.apm.network.common.v3.Commands;
  import org.apache.skywalking.apm.network.language.agent.v3.SegmentObject;
  import org.apache.skywalking.apm.network.language.agent.v3.TraceSegmentReportServiceGrpc;
  
  import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
  
  public class GRPCNoServerTest {
      public static void main(String[] args) throws InterruptedException {
          ManagedChannelBuilder<?> channelBuilder = NettyChannelBuilder.forAddress("127.0.0.1", 8080)
                                                                       .nameResolverFactory(new DnsNameResolverProvider())
                                                                       .maxInboundMessageSize(1024 * 1024 * 50)
                                                                       .usePlaintext();
          ManagedChannel channel = channelBuilder.build();
          TraceSegmentReportServiceGrpc.TraceSegmentReportServiceStub serviceStub = TraceSegmentReportServiceGrpc.newStub(channel);
          final Status[] status = {null};
          StreamObserver<SegmentObject> streamObserver = serviceStub.collect(new StreamObserver<Commands>() {
              @Override
              public void onNext(Commands value) {
  
              }
  
              @Override
              public void onError(Throwable t) {
                  status[0] = ((StatusRuntimeException) t).getStatus();
              }
  
              @Override
              public void onCompleted() {
  
              }
          });
  
          streamObserver.onNext(null);
          streamObserver.onCompleted();
  
          Thread.sleep(2 * 1000);
  
          assertThat(status[0].getCode()).isEqualTo(Status.UNAVAILABLE.getCode());
      }
  }
  