Source for java.net.Inet4Address

   1: /* Inet4Address.java --
   2:    Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package java.net;
  40: 
  41: import gnu.java.lang.CPStringBuilder;
  42: 
  43: import java.io.ObjectStreamException;
  44: 
  45: /*
  46:  * Written using on-line Java Platform 1.4 API Specification and
  47:  * RFC 1884 (http://www.ietf.org/rfc/rfc1884.txt),
  48:  * RFC 1918 (http://www.ietf.org/rfc/rfc1918.txt),
  49:  * RFC 2365 (http://www.ietf.org/rfc/rfc2365.txt)
  50:  *
  51:  * @author Michael Koch
  52:  * @status Believed complete and correct.
  53:  */
  54: public final class Inet4Address extends InetAddress
  55: {
  56:   /**
  57:    * For compatability with Sun's JDK 1.4.2 rev. 5
  58:    */
  59:   static final long serialVersionUID = 3286316764910316507L;
  60: 
  61:   /**
  62:    * The address family of these addresses (used for serialization).
  63:    */
  64:   private static final int AF_INET = 2;
  65: 
  66:   /**
  67:    * Inet4Address objects are serialized as InetAddress objects.
  68:    */
  69:   private Object writeReplace() throws ObjectStreamException
  70:   {
  71:     return new InetAddress(addr, hostName, AF_INET);
  72:   }
  73: 
  74:   /**
  75:    * Initializes this object's addr instance variable from the passed in
  76:    * byte array.  Note that this constructor is protected and is called
  77:    * only by static methods in this class.
  78:    *
  79:    * @param addr The IP number of this address as an array of bytes
  80:    * @param host The hostname of this IP address.
  81:    */
  82:   Inet4Address(byte[] addr, String host)
  83:   {
  84:     super(addr, host, AF_INET);
  85:   }
  86: 
  87:   /**
  88:    * Checks if the address is a multicast address
  89:    *
  90:    * @since 1.1
  91:    */
  92:   public boolean isMulticastAddress()
  93:   {
  94:     return (addr[0] & 0xf0) == 0xe0;
  95:   }
  96: 
  97:   /**
  98:    * Checks if this address is a loopback address
  99:    */
 100:   public boolean isLoopbackAddress()
 101:   {
 102:     return (addr[0] & 0xff) == 0x7f;
 103:   }
 104: 
 105:   /**
 106:    * Checks if this address is a wildcard address
 107:    *
 108:    * @since 1.4
 109:    */
 110:   public boolean isAnyLocalAddress()
 111:   {
 112:     return equals(InetAddress.ANY_IF);
 113:   }
 114: 
 115:   /**
 116:    * Checks if this address is a link local address
 117:    *
 118:    * @since 1.4
 119:    */
 120:   public boolean isLinkLocalAddress()
 121:   {
 122:     return false;
 123:   }
 124: 
 125:   /**
 126:    * Checks if this address is a site local address
 127:    *
 128:    * @since 1.4
 129:    */
 130:   public boolean isSiteLocalAddress()
 131:   {
 132:     // 10.0.0.0/8
 133:     if ((addr[0] & 0xff) == 0x0a)
 134:       return true;
 135: 
 136:     // 172.16.0.0/12
 137:     if ((addr[0] & 0xff) == 0xac && (addr[1] & 0xf0) == 0x10)
 138:       return true;
 139: 
 140:     // 192.168.0.0/16
 141:     if ((addr[0] & 0xff) == 0xc0 && (addr[1] & 0xff) == 0xa8)
 142:       return true;
 143: 
 144:     return false;
 145:   }
 146: 
 147:   /**
 148:    * Checks if this multicast address has global scope
 149:    *
 150:    * @since 1.4
 151:    */
 152:   public boolean isMCGlobal()
 153:   {
 154:     return false;
 155:   }
 156: 
 157:   /**
 158:    * Checks if this multicast address has node scope
 159:    *
 160:    * @since 1.4
 161:    */
 162:   public boolean isMCNodeLocal()
 163:   {
 164:     return false;
 165:   }
 166: 
 167:   /**
 168:    * Checks if this multicast address has link scope
 169:    *
 170:    * @since 1.4
 171:    */
 172:   public boolean isMCLinkLocal()
 173:   {
 174:     if (! isMulticastAddress())
 175:       return false;
 176: 
 177:     return ((addr[0] & 0xff) == 0xe0
 178:             && (addr[1] & 0xff)  == 0x00
 179:             && (addr[2] & 0xff)  == 0x00);
 180:   }
 181: 
 182:   /**
 183:    * Checks if this multicast address has site scope
 184:    *
 185:    * @since 1.4
 186:    */
 187:   public boolean isMCSiteLocal()
 188:   {
 189:     return false;
 190:   }
 191: 
 192:   /**
 193:    * Checks if this multicast address has organization scope
 194:    *
 195:    * @since 1.4
 196:    */
 197:   public boolean isMCOrgLocal()
 198:   {
 199:     return false;
 200:   }
 201: 
 202:   /**
 203:    * Returns the address of the current instance
 204:    */
 205:   public byte[] getAddress()
 206:   {
 207:     return (byte[]) addr.clone();
 208:   }
 209: 
 210:   /**
 211:    * Returns the address as string
 212:    *
 213:    * @since 1.0.2
 214:    */
 215:   public String getHostAddress()
 216:   {
 217:     CPStringBuilder sb = new CPStringBuilder(40);
 218: 
 219:     int len = addr.length;
 220:     int i = 0;
 221: 
 222:     for ( ; ; )
 223:       {
 224:         sb.append(addr[i] & 0xff);
 225:         i++;
 226: 
 227:         if (i == len)
 228:           break;
 229: 
 230:         sb.append('.');
 231:       }
 232: 
 233:     return sb.toString();
 234:   }
 235: 
 236:   /**
 237:    * Computes the hashcode of the instance
 238:    */
 239:   public int hashCode()
 240:   {
 241:     int hash = 0;
 242:     int len = addr.length;
 243:     int i = len > 4 ? len - 4 : 0;
 244: 
 245:     for (; i < len; i++)
 246:       hash = (hash << 8) | (addr[i] & 0xFF);
 247: 
 248:     return hash;
 249:   }
 250: 
 251:   /**
 252:    * Compare the current Inet4Address instance with obj
 253:    *
 254:    * @param obj Object to compare with
 255:    */
 256:   public boolean equals(Object obj)
 257:   {
 258:     if (! (obj instanceof InetAddress))
 259:       return false;
 260: 
 261:     byte[] addr1 = addr;
 262:     byte[] addr2 = ((InetAddress) obj).addr;
 263: 
 264:     if (addr1.length != addr2.length)
 265:       return false;
 266: 
 267:     for (int i = addr1.length; --i >= 0;)
 268:       if (addr1[i] != addr2[i])
 269:         return false;
 270: 
 271:     return true;
 272:   }
 273: }