Convert a TCP/IP address string into a byte array
/*
* Copyright (C) 2006-2008 Alfresco Software Limited.
*
* 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; either version 2
* of the License, or (at your option) any later version.
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* As a special exception to the terms and conditions of version 2.0 of
* the GPL, you may redistribute this Program in connection with Free/Libre
* and Open Source Software ("FLOSS") applications as described in Alfresco's
* FLOSS exception. You should have recieved a copy of the text describing
* the FLOSS exception, and it is also available here:
* http://www.alfresco.com/legal/licensing"
*/
//package net.gqu.utils;
import java.util.StringTokenizer;
/**
* TCP/IP Address Utility Class
*
* @author gkspencer
*/
public class IPAddress {
/**
* Convert a TCP/IP address string into a byte array
*
* @param addr String
* @return byte[]
*/
public final static byte[] asBytes(String addr) {
// Convert the TCP/IP address string to an integer value
int ipInt = parseNumericAddress(addr);
if ( ipInt == 0)
return null;
// Convert to bytes
byte[] ipByts = new byte[4];
ipByts[3] = (byte) (ipInt & 0xFF);
ipByts[2] = (byte) ((ipInt >> 8) & 0xFF);
ipByts[1] = (byte) ((ipInt >> 16) & 0xFF);
ipByts[0] = (byte) ((ipInt >> 24) & 0xFF);
// Return the TCP/IP bytes
return ipByts;
}
/**
* Check if the specified address is a valid numeric TCP/IP address and return as an integer value
*
* @param ipaddr String
* @return int
*/
public final static int parseNumericAddress(String ipaddr) {
// Check if the string is valid
if ( ipaddr == null || ipaddr.length() < 7 || ipaddr.length() > 15)
return 0;
// Check the address string, should be n.n.n.n format
StringTokenizer token = new StringTokenizer(ipaddr,".");
if ( token.countTokens() != 4)
return 0;
int ipInt = 0;
while ( token.hasMoreTokens()) {
// Get the current token and convert to an integer value
String ipNum = token.nextToken();
try {
// Validate the current address part
int ipVal = Integer.valueOf(ipNum).intValue();
if ( ipVal < 0 || ipVal > 255)
return 0;
// Add to the integer address
ipInt = (ipInt << 8) + ipVal;
}
catch (NumberFormatException ex) {
return 0;
}
}
// Return the integer address
return ipInt;
}
}
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