Question

在我的java RMI应用程序中，我可以拥有在本地和不同主机上充当服务器的实例。在后一种情况下，如何获取我的传出IP地址，以便将其设置为系统属性java.rmi.server.hostName的参数？

现在它很难接线，但这不是一个理想的解决方案。

Answer 1

您可以使用经典的Java方式：

try {
    InetAddress addr = InetAddress.getLocalHost();

    // Get IP Address
    byte[] ipAddr = addr.getAddress();

    // Get hostname
    String hostname = addr.getHostName();
} catch (UnknownHostException e) {
}

Answer 2

我不明白为什么你认为你需要这个。传出存根中的源地址自动设置为主机的IP地址。您需要设置此属性的唯一时间是默认设置不正确：例如如果您有多个NIC并且只想通过一个NIC导出，或者您的Linux配置错误将主机名映射到127.0.0.1而不是您的IP地址。

Answer 3

以下内容将显示主机上所有可用的非环回IPv4地址。您也可以轻松地对其进行调整以获取IPv6地址。

public static void main(String...args) {
  List<InetAddress> addresses = getNonLocalIPV4Addresses();
  for (InetAddress addr: addresses) {
    System.out.println("address: " + addr.getHostAddress());
  }
}

/**
 * Get a list of all known non-local IP v4 addresses for the current host.
 * @return a List of <code>InetAddress</code>, may be empty but never null.
 */
public static List<InetAddress> getNonLocalIPV4Addresses() {
  return getIPAddresses(new InetAddressFilter() {
    public boolean accepts(InetAddress addr) {
      return (addr instanceof Inet4Address)
        && !(addr.isLoopbackAddress()) || "localhost".equals(addr.getHostName()));
    }
  });
}

/**
 * Get a list of all known IP addresses for the current host,
 * according to the specified filter.
 * @param filter filters out unwanted addresses.
 * @return a List of <code>InetAddress</code>, may be empty but never null.
 */
public static List<InetAddress> getIPAddresses(InetAddressFilter filter) {
  List<InetAddress> list = new ArrayList<InetAddress>();
  try {
    Enumeration<NetworkInterface> interfaces =
      NetworkInterface.getNetworkInterfaces();
    while (interfaces.hasMoreElements()) {
      NetworkInterface ni = interfaces.nextElement();
      Enumeration<InetAddress> addresses = ni.getInetAddresses();
      while (addresses.hasMoreElements()) {
        InetAddress addr = addresses.nextElement();
        if ((filter == null) || filter.accepts(addr)) list.add(addr);
      }
    }
  } catch(Exception e) {
    e.printStackTrace();
  }
  return list;
}

/**
 * Filter interface for the methods discovering available IP addresses. 
 */
public interface InetAddressFilter {
  /**
   * Determine whether the specified address is accepted.
   * @param addr the address to check.
   * @return true if the address is accepted, false otherwise.
   */
  boolean accepts(InetAddress addr);
}

在Java RMI中获取传出IP地址

3 个答案: