content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * Licensed 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.nacos.client.naming.utils;
  
  import com.alibaba.nacos.client.utils.StringUtils;
  
  import java.net.InetAddress;
  import java.net.UnknownHostException;
  
  /**
   * @author xuanyin.zy
   */
  public class NetUtils {
      private static String LOCAL_IP;
  
      public static String localIP() {
          try {
              if (!StringUtils.isEmpty(LOCAL_IP)) {
                  return LOCAL_IP;
              }
  
              String ip = System.getProperty("com.alibaba.nacos.client.naming.local.ip", InetAddress.getLocalHost().getHostAddress());
  
              return LOCAL_IP = ip;
          } catch (UnknownHostException e) {
              return "resolve_failed";
          }
      }
  }
  