用以下代码

 hostaddress = InetAddress.getLocalHost().getHostAddress()

在大部分情况下可以正确获取到本机的IP地址。但是在不能联网的情况下，或者手动修改过hosts文件的情况下，你可能获取到的是

127.0.0.1

那么如何能够准确的获取到本机的IP呢？

我们看看Solr是如何做的： 

// normalize host removing any url scheme.  // input can be null, host, or url_prefix://host  private String normalizeHostName(String host) throws IOException {    if (host == null || host.length() == 0) {      String hostaddress;      try {        hostaddress = InetAddress.getLocalHost().getHostAddress();      } catch (UnknownHostException e) {        hostaddress = "127.0.0.1"; // cannot resolve system hostname, fall through      }      // Re-get the IP again for "127.0.0.1", the other case we trust the hosts      // file is right.      if ("127.0.0.1".equals(hostaddress)) {        Enumeration
    
      netInterfaces = null;        try {          netInterfaces = NetworkInterface.getNetworkInterfaces();          while (netInterfaces.hasMoreElements()) {            NetworkInterface ni = netInterfaces.nextElement();            Enumeration
     
       ips = ni.getInetAddresses();            while (ips.hasMoreElements()) {              InetAddress ip = ips.nextElement();              if (ip.isSiteLocalAddress()) {                hostaddress = ip.getHostAddress();              }            }          }        } catch (Exception e) {          SolrException.log(log,              "Error while looking for a better host name than 127.0.0.1", e);        }      }      host = hostaddress;    } else {      if (URLUtil.hasScheme(host)) {        host = URLUtil.removeScheme(host);      }    }    return host;  }