Java实现获取本机上ADSL的IP

import java.net.*;
public class GetIp {

 public static int isInnerIP(long a_ip)//检查ip地址是否是内网ip
 {
  int bValid = -1;
  if ((a_ip >> 24 == 0xa) || (a_ip >> 16 == 0xc0a8) || (a_ip >> 22 == 0x2b0))
  {
   bValid = 0;
  }
  return bValid;
 }
 
 // 将127.0.0.1 形式的IP地址转换成10进制整数，这里没有进行任何错误处理
 public static long ipToLong(String strIP)
 {
  long[] ip = new long[4];
  //先找到IP地址字符串中.的位置
  int position1 = strIP.indexOf(".");
  int position2 = strIP.indexOf(".", position1 + 1);
  int position3 = strIP.indexOf(".", position2 + 1);
  //将每个.之间的字符串转换成整型
  ip[0] = Long.parseLong(strIP.substring(0, position1));
  ip[1] = Long.parseLong(strIP.substring(position1 + 1, position2));
  ip[2] = Long.parseLong(strIP.substring(position2 + 1, position3));
  ip[3] = Long.parseLong(strIP.substring(position3 + 1));
  return (ip[0] << 24) + (ip[1] << 16) + (ip[2] << 8) + ip[3];
 }
 
 public static void main(String[] args) {
  String ip;
  try
  {
   InetAddress in = InetAddress.getLocalHost();
   InetAddress[] all = InetAddress.getAllByName(in.getHostName());
   //通过本机主机名，遍历多个ip   
   for (int i = 0; i < all.length; i++)
   {
    String tmp=null;
    tmp=ip=all[i].getHostAddress().toString();
    System.out.println("IP =  " +tmp);//输出计算机所有的ip地址
    if (isInnerIP(ipToLong(tmp)) == -1)//检查是不是外网ip，如果是就保存文件
    {
     /*WriteFile(ip);//将ip地址写入文件
     System.out.println("IP保存在同目录IP.txt文件中");

     System.out.println("同目录IP.txt文件中的IP是：" + ReadFile());*/
     System.out.println(ip);
     
    }
   }
  }
  catch (UnknownHostException e)
  {
   System.out.println(e.getMessage());
  }
 }
}