/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program 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. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Jan 13, 2009
*/
package com.bigdata.net;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Utility methods for working around some known issues.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*
* @deprecated this was a red herring.
*/
public class InetAddressUtil {
/** {@link Pattern} matching IPV4 addresses. */
static private final Pattern ipv4 = Pattern
.compile("^([0-9]+)\\.([0-9]+)\\.([0-9]+)\\.([0-9]+)$");
/**
* There is a bug with reverse DNS lookup in
* {@link InetAddress#getByName(String)} when presented with a IP address
* rather than a host name. It will always attempt reverse DNS lookup of the
* IP address. Therefore if reverse DNS is NOT setup correctly, a
* significant delay (4-5 seconds on Windows) will occur for each lookup and
* resolution may fail with an {@link UnknownHostException}.
*
* @throws UnknownHostException
*
* @see http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5092063
*
* @todo this does not handle IPV6
*/
public static InetAddress getByName(String s) throws UnknownHostException {
if (s == null)
throw new NullPointerException();
final Matcher m = ipv4.matcher(s);
if(m.matches()) {
byte a = encodeByte(Integer.parseInt(m.group(1)) - 128);
byte b = encodeByte(Integer.parseInt(m.group(2)) - 128);
byte c = encodeByte(Integer.parseInt(m.group(3)) - 128);
byte d = encodeByte(Integer.parseInt(m.group(4)) - 128);
return InetAddress.getByAddress(s, new byte[] { a, b, c, d });
}
return InetAddress.getByName(s);
}
/**
* Converts an unsigned byte into a signed byte.
*
* @param v
* The unsigned byte.
*
* @return The corresponding signed value.
*/
final static byte decodeByte(final int v) {
int i = v;
if (i < 0) {
i = i + 0x80;
} else {
i = i - 0x80;
}
return (byte) (i & 0xff);
}
/**
* Converts a signed byte into an unsigned byte.
*
* @param v
* The signed byte.
*
* @return The corresponding unsigned value.
*/
final static byte encodeByte(final int v) {
if (v > 127 || v < -128)
throw new IllegalArgumentException("v=" + v);
int i = v;
if (i < 0) {
i = i - 0x80;
} else {
i = i + 0x80;
}
return (byte) (i & 0xff);
}
}