android获取网关ip

最近项目里有需求在android程序里获取系统的网关ip，最初的方案是通过

Process localProcess = Runtime.getRuntime().exec("router ")

但发现，这样子实行不通的，后来觉得麻烦，就在 android.net包里搜了一遍，让我给逮到了一个android.net.DhcpInfo，这个类里面

就存储着网关ip的数据，在此，我把获取网关ip的代码贴下来，供大家参考。

下面是获取网关的方法

public static String getGateWay() {
if (Netgear_WifiManager.wifiManager != null)
{
DhcpInfo   dhcpInfo=Netgear_WifiManager.wifiManager.getDhcpInfo();
Log.e("gateway is ",
Netgear_IpAddressTranfer.long2ip(dhcpInfo.gateway));
}
return null;
}

由于DhcpInfo类提供的网关ip是个整数，因此还得将整数转为ip格式才可以

public class Netgear_IpAddressTranfer {
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;
x = Integer.toString(b[3]) + "." + Integer.toString(b[2]) + "."
+ Integer.toString(b[1]) + "." + Integer.toString(b[0]);
return x;
}
/****
* 获取默认网关的ＩＰ地址
*
* @return
* @throws Exception
*/
public static String getDefaultGatewayIp() throws Exception {
try {
Process result = Runtime.getRuntime().exec("su");
BufferedReader output = new BufferedReader(new InputStreamReader(
result.getInputStream()));
String line = output.readLine();
while (line != null) {
Log.e("new line is ", line);
line = output.readLine();
}
} catch (Exception e) {
System.out.println(e.toString());
}
return null;
}
}