最近用到了动网的IP库，但是数据库字段用long类型存放，因为动网用的是php系统，php里有一个直接的ip2long的方法。但是java就需要DIY.
import java.net.*;//导入包
public class ip2long {
public static int str2Ip(String ip) throws UnknownHostException {
InetAddress address = InetAddress.getByName(ip);//在给定主机名的情况下确定主机的 IP 址。
byte[] bytes = address.getAddress();//返回此 InetAddress 对象的原始 IP 地址
int a, b, c, d;
a = byte2int(bytes[0]);
b = byte2int(bytes[1]);
c = byte2int(bytes[2]);
d = byte2int(bytes[3]);
int result = (a << 24) | (b << 16) | (c << 8) | d;
return result;
}
public static int byte2int(byte b) {
int l = b & 0x07f;
if (b < 0) {
l |= 0x80;
}
return l;
}
public static long ip2long(String ip) throws UnknownHostException {
int ipNum = str2Ip(ip);
return int2long(ipNum);
}
public static long int2long(int i) {
long l = i & 0x7fffffffL;
if (i < 0) {
l |= 0x080000000L;
}
return l;
}
public static String long2ip(long ip) {
int[] b = new int[4];
b[0] = (int) ( (ip >> 24) & 0xff);
b[1] = (int) ( (ip >> 16) & 0xff);
b[2] = (int) ( (ip >> 8) & 0xff);
b[3] = (int) (ip & 0xff);
String x;
Integer p;
p = new Integer(0);
x = p.toString(b[0]) + "." + p.toString(b[1]) + "." + p.toString(b[2]) +
"." + p.toString(b[3]);
return x;
}
//测试函数
public static void main(String[] args) throws Exception {
long ip = ip2long("1.0.0.0");
System.out.println(ip);
System.out.println(long2ip(ip));
}
}
