ec.util

Class LocalHost

java.lang.Object

ec.util.LocalHost

public class LocalHost
extends java.lang.Object

Modified from apache mail-archives. This code was published in the public domain, but I believe it was probably intended to be distributed under the Apache license, like the rest of the Jakarta code. That license is listed at the end of this file.

Constructor Summary

Constructors

Constructor and Description
LocalHost()

Method Summary

Modifier and Type	Method and Description
static java.net.InetAddress	getLocalHost() Returns an InetAddress object encapsulating what is most likely the machine's LAN IP address.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LocalHost

public LocalHost()

Method Detail

getLocalHost

public static java.net.InetAddress getLocalHost()
                                         throws java.net.UnknownHostException

Returns an InetAddress object encapsulating what is most likely the machine's LAN IP address.

This method is intended for use as a replacement of JDK method InetAddress.getLocalHost, because that method is ambiguous on Linux systems. Linux systems enumerate the loopback network interface the same way as regular LAN network interfaces, but the JDK InetAddress.getLocalHost method does not specify the algorithm used to select the address returned under such circumstances, and will often return the loopback address, which is not valid for network communication. Details here.

This method will scan all IP addresses on all network interfaces on the host machine to determine the IP address most likely to be the machine's LAN address. If the machine has multiple IP addresses, this method will prefer a site-local IP address (e.g. 192.168.x.x or 10.10.x.x, usually IPv4) if the machine has one (and will return the first site-local address if the machine has more than one), but if the machine does not hold a site-local address, this method will return simply the first non-loopback address found (IPv4 or IPv6).

If this method cannot find a non-loopback address using this selection algorithm, it will fall back to calling and returning the result of JDK method InetAddress.getLocalHost.

Throws:

java.net.UnknownHostException - If the LAN address of the machine cannot be found.