com.mchange.v2.net.LocalHostManager Maven / Gradle / Ivy
/*
* Distributed as part of mchange-commons-java 0.2.11
*
* Copyright (C) 2015 Machinery For Change, Inc.
*
* Author: Steve Waldman
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of EITHER:
*
* 1) The GNU Lesser General Public License (LGPL), version 2.1, as
* published by the Free Software Foundation
*
* OR
*
* 2) The Eclipse Public License (EPL), version 1.0
*
* You may choose which license to accept if you wish to redistribute
* or modify this work. You may offer derivatives of this work
* under the license you have chosen, or you may provide the same
* choice of license which you have been offered here.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* You should have received copies of both LGPL v2.1 and EPL v1.0
* along with this software; see the files LICENSE-EPL and LICENSE-LGPL.
* If not, the text of these licenses are currently available at
*
* LGPL v2.1: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* EPL v1.0: http://www.eclipse.org/org/documents/epl-v10.php
*
*/
package com.mchange.v2.net;
import java.net.*;
import java.util.*;
public class LocalHostManager
{
Set localAddresses;
Set knownGoodNames;
Set knownBadNames;
public synchronized void update() throws SocketException
{
Set tmp = new HashSet();
Enumeration netintfcs = NetworkInterface.getNetworkInterfaces();
while (netintfcs.hasMoreElements())
{
NetworkInterface ni = (NetworkInterface) netintfcs.nextElement();
Enumeration addresses = ni.getInetAddresses();
while (addresses.hasMoreElements())
tmp.add( addresses.nextElement() );
}
this.localAddresses = Collections.unmodifiableSet( tmp );
this.knownGoodNames = new HashSet();
this.knownBadNames = new HashSet();
}
public synchronized Set getLocalAddresses()
{ return localAddresses; }
public synchronized boolean isLocalAddress(InetAddress addr)
{ return localAddresses.contains( addr ); }
public synchronized boolean isLocalHostName( String name )
{
if ( knownGoodNames.contains( name ) )
return true;
else if ( knownBadNames.contains( name ) )
return false;
else
{
try
{
InetAddress nameAddr = InetAddress.getByName( name );
if ( localAddresses.contains( nameAddr ) )
{
knownGoodNames.add( name );
return true;
}
else
{
knownBadNames.add( name );
return false;
}
}
catch (UnknownHostException e)
{
knownBadNames.add( name );
return false;
}
}
}
public LocalHostManager() throws SocketException
{ update(); }
public static void main( String[] argv )
{
try
{
LocalHostManager lhm = new LocalHostManager();
System.out.println( lhm.getLocalAddresses() );
}
catch (Exception e)
{ e.printStackTrace(); }
}
}