nslookup和Java的InetAddress getHostName之间的结果不同

2 回答

• 1

  您的计算机可能未默认配置为使用DNS，即使它是按需提供的 .

  我会尝试

  ping 82.117.193.169
  

  并查看它是否将IP地址解析为主机名 .

  回复于 2024-05-05T19:05:46+08:00
• 1

  这是由于“A”记录检查 - Java希望你正在查找的IP号码被列在那里 . 他们称之为“XXX”，我明白为什么：

  private static String getHostFromNameService(InetAddress addr, boolean check) {
  String host = null;
  for (NameService nameService : nameServices) {
      try {
          // first lookup the hostname
          host = nameService.getHostByAddr(addr.getAddress());
  
          /* check to see if calling code is allowed to know
           * the hostname for this IP address, ie, connect to the host
           */
          if (check) {
              SecurityManager sec = System.getSecurityManager();
              if (sec != null) {
                  sec.checkConnect(host, -1);
              }
          }
  
          /* now get all the IP addresses for this hostname,
           * and make sure one of them matches the original IP
           * address. We do this to try and prevent spoofing.
           */
  
          InetAddress[] arr = InetAddress.getAllByName0(host, check);
          boolean ok = false;
  
          if(arr != null) {
              for(int i = 0; !ok && i < arr.length; i++) {
                  ok = addr.equals(arr[i]);
              }
          }
  
          //XXX: if it looks a spoof just return the address?
          if (!ok) {
              host = addr.getHostAddress();
              return host;
          }
  
          break;
  

  回复于 2024-05-05T19:05:46+08:00