If you account for multiple interfaces, and some null MAC addresses (I'm running Java 7 on Windows 7 with VMWare installed (so I have some virtual network adapters)) then this code seems to work:
public static void main(String[] args) {
try {
InetAddress ip = InetAddress.getLocalHost();
System.out.println("Current IP address : " + ip.getHostAddress());
Enumeration<NetworkInterface> networks = NetworkInterface.getNetworkInterfaces();
while(networks.hasMoreElements()) {
NetworkInterface network = networks.nextElement();
byte[] mac = network.getHardwareAddress();
if(mac != null) {
System.out.print("Current MAC address : ");
StringBuilder sb = new StringBuilder();
for (int i = 0; i < mac.length; i++) {
sb.append(String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : ""));
}
System.out.println(sb.toString());
}
}
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (SocketException e){
e.printStackTrace();
}
}
Here is (a sanitized version of) what I see on my computer when I run it:
Current IP address : {I'm not telling :)}
Current MAC address :
Current MAC address : {actual hardware interface}
Current MAC address : 00-00-00-00-00-00-00-E0
Current MAC address : 00-00-00-00-00-00-00-E0
Current MAC address : 00-00-00-00-00-00-00-E0
Current MAC address : 00-00-00-00-00-00-00-E0
Current MAC address : 00-00-00-00-00-00-00-E0
Current MAC address : 00-50-56-C0-00-01
Current MAC address : 00-50-56-C0-00-08
And here is the output of running ipconfig /all
C:\>ipconfig /all
Windows IP Configuration (minus any actual interface because I don't like sharing that kind of information :)
Ethernet adapter Local Area Connection 2:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Gbridge Virtual Private Network Adapter
Physical Address. . . . . . . . . : 02-50-F2-CE-82-01
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Ethernet adapter VMware Network Adapter VMnet1:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : VMware Virtual Ethernet Adapter for VMnet1
Physical Address. . . . . . . . . : 00-50-56-C0-00-01
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::9c27:3d03:da2c:f14d%19(Preferred)
Autoconfiguration IPv4 Address. . : {Hidden}(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.0.0
Default Gateway . . . . . . . . . :
DHCPv6 IAID . . . . . . . . . . . : 268456022
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-13-DB-D9-CB-B8-AC-6F-AF-9D-F2
DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1
fec0:0:0:ffff::2%1
fec0:0:0:ffff::3%1
NetBIOS over Tcpip. . . . . . . . : Enabled
Ethernet adapter VMware Network Adapter VMnet8:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : VMware Virtual Ethernet Adapter for VMnet8
Physical Address. . . . . . . . . : 00-50-56-C0-00-08
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::cdbb:434:7fd9:2574%20(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.42.1(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . :
DHCPv6 IAID . . . . . . . . . . . : 285233238
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-13-DB-D9-CB-B8-AC-6F-AF-9D-F2
DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1
fec0:0:0:ffff::2%1
fec0:0:0:ffff::3%1
NetBIOS over Tcpip. . . . . . . . : Enabled
Tunnel adapter 6TO4 Adapter:
Description . . . . . . . . . . . : Microsoft 6to4 Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2002:204c:1bc6::204c:1bc6(Preferred)
Default Gateway . . . . . . . . . :
NetBIOS over Tcpip. . . . . . . . : Disabled
Tunnel adapter isatap.{3E45CB42-BC1E-4F89-9C16-25166C0EABA1}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter isatap.{77F1FADC-02BA-44AF-9FDF-97E23F8B5FE7}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter isatap.{608257AC-C0F3-43A5-8595-898533C95D90}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #5
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
The challenge in getting "just one value" from this mess comes from the relationship between InetAddress.getLocalHost().getHostAddress() and the network interfaces themselves. Consider this slight expanded version of the initial program (using this really cool IterableEnumeration utility class):
public static void main(String[] args) throws UnknownHostException, SocketException {
System.out.println("Current IP address : " + InetAddress.getLocalHost().getHostAddress());
for(NetworkInterface network : IterableEnumeration.make(NetworkInterface.getNetworkInterfaces())) {
byte[] mac = network.getHardwareAddress();
if(mac != null) {
System.out.print("Current MAC address : ");
StringBuilder sb = new StringBuilder();
for (int i = 0; i < mac.length; i++) {
sb.append(String.format("%02X%s", mac[i], (i < mac.length - 1) ? "-" : ""));
}
System.out.println(sb.toString());
//Bound InetAddress for interface
for(InetAddress address : IterableEnumeration.make(network.getInetAddresses())) {
System.out.println("\tBound to:"+address.getHostAddress());
}
}
}
}
If you run this on your computer you will see your current IP address correlates to one adapter but that MAC address of your hardware interface sees it's self as a different IP address. Maybe you can filter out virtual addresses or just find a way to utilize all available addresses.
