NetworkInterface: isUp()
import java.net.InterfaceAddress; import java.net.NetworkInterface; import java.net.SocketException; import java.util.Enumeration; import java.util.Iterator; import java.util.List; public class Main { public static void main(String[] args) throws Exception { Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); while (en.hasMoreElements()) { NetworkInterface ni = en.nextElement(); printParameter(ni); } } public static void printParameter(NetworkInterface ni) throws SocketException { System.out.println(" Name = " + ni.getName()); System.out.println(" Display Name = " + ni.getDisplayName()); System.out.println(" Is up = " + ni.isUp()); System.out.println(" Support multicast = " + ni.supportsMulticast()); System.out.println(" Is loopback = " + ni.isLoopback()); System.out.println(" Is virtual = " + ni.isVirtual()); System.out.println(" Is point to point = " + ni.isPointToPoint()); System.out.println(" Hardware address = " + ni.getHardwareAddress()); System.out.println(" MTU = " + ni.getMTU()); System.out.println("\nList of Interface Addresses:"); List<InterfaceAddress> list = ni.getInterfaceAddresses(); Iterator<InterfaceAddress> it = list.iterator(); while (it.hasNext()) { InterfaceAddress ia = it.next(); System.out.println(" Address = " + ia.getAddress()); System.out.println(" Broadcast = " + ia.getBroadcast()); System.out.println(" Network prefix length = " + ia.getNetworkPrefixLength()); System.out.println(""); } } }