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.library.client.grpc;
  
  import io.grpc.ManagedChannel;
  import io.grpc.ManagedChannelBuilder;
  import io.grpc.netty.NettyChannelBuilder;
  import io.netty.handler.ssl.SslContext;
  import lombok.Getter;
  import org.apache.skywalking.oap.server.library.client.Client;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class GRPCClient implements Client {
  
      private static final Logger LOGGER = LoggerFactory.getLogger(GRPCClient.class);
  
      @Getter
      private final String host;
  
      @Getter
      private final int port;
  
      private SslContext sslContext;
  
      private ManagedChannel channel;
  
      public GRPCClient(String host, int port) {
          this.host = host;
          this.port = port;
      }
  
      public GRPCClient(String host, int port, final SslContext sslContext) {
          this(host, port);
          this.sslContext = sslContext;
      }
  
      @Override
      public void connect() {
          if (sslContext == null) {
              channel = ManagedChannelBuilder.forAddress(host, port).usePlaintext().build();
              return;
          }
          channel = NettyChannelBuilder.forAddress(host, port).sslContext(sslContext).build();
      }
  
      @Override
      public void shutdown() {
          try {
              channel.shutdownNow();
          } catch (Throwable t) {
              LOGGER.error(t.getMessage(), t);
          }
      }
  
      public ManagedChannel getChannel() {
          return channel;
      }
  
      @Override
      public String toString() {
          return host + ":" + port;
      }
  }
  