Java Local Host Get getLocalHostLANAddress()

Description

get Local Host LAN Address

License

Open Source License

Declaration

public static InetAddress getLocalHostLANAddress() throws UnknownHostException 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.UnknownHostException;
import java.util.Enumeration;

public class Main {
    public static InetAddress getLocalHostLANAddress() throws UnknownHostException {
        try {//from  w ww.j  av a 2s .  com
            InetAddress candidateAddress = null;
            // Iterate all NICs (network interface cards)...
            for (Enumeration ifaces = NetworkInterface.getNetworkInterfaces(); ifaces.hasMoreElements();) {
                NetworkInterface iface = (NetworkInterface) ifaces.nextElement();
                // Iterate all IP addresses assigned to each card...
                for (Enumeration inetAddrs = iface.getInetAddresses(); inetAddrs.hasMoreElements();) {
                    InetAddress inetAddr = (InetAddress) inetAddrs.nextElement();
                    if (!inetAddr.isLoopbackAddress()) {

                        if (inetAddr.isSiteLocalAddress()) {
                            // Found non-loopback site-local address. Return it immediately...
                            return inetAddr;
                        } else if (candidateAddress == null) {
                            // Found non-loopback address, but not necessarily site-local.
                            // Store it as a candidate to be returned if site-local address is not subsequently found...
                            candidateAddress = inetAddr;
                            // Note that we don't repeatedly assign non-loopback non-site-local addresses as candidates,
                            // only the first. For subsequent iterations, candidate will be non-null.
                        }
                    }
                }
            }
            if (candidateAddress != null) {
                // We did not find a site-local address, but we found some other non-loopback address.
                // Server might have a non-site-local address assigned to its NIC (or it might be running
                // IPv6 which deprecates the "site-local" concept).
                // Return this non-loopback candidate address...
                return candidateAddress;
            }
            // At this point, we did not find a non-loopback address.
            // Fall back to returning whatever InetAddress.getLocalHost() returns...
            InetAddress jdkSuppliedAddress = InetAddress.getLocalHost();
            if (jdkSuppliedAddress == null) {
                throw new UnknownHostException(
                        "The JDK InetAddress.getLocalHost() method unexpectedly returned null.");
            }
            return jdkSuppliedAddress;
        } catch (Exception e) {
            UnknownHostException unknownHostException = new UnknownHostException(
                    "Failed to determine LAN address: " + e);
            unknownHostException.initCause(e);
            throw unknownHostException;
        }
    }
}

Related

1. getLocalHost()
2. getLocalHostAddress()
3. getLocalhostAddress()
4. getLocalHostAddress()
5. getLocalHostID()
6. getLocalHostName()
7. getLocalHostName()
8. getLocalHostName()
9. getLocalHostname()