Source for java.net.NetworkInterface

   1: /* NetworkInterface.java --
   2:    Copyright (C) 2002, 2003, 2004, 2005  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 java.util.Collection;
  42: import java.util.Collections;
  43: import java.util.Enumeration;
  44: import java.util.HashMap;
  45: import java.util.Iterator;
  46: import java.util.Map;
  47: import java.util.Vector;
  48: 
  49: /**
  50:  * This class models a network interface on the host computer.  A network
  51:  * interface contains a name (typically associated with a specific
  52:  * hardware adapter) and a list of addresses that are bound to it.
  53:  * For example, an ethernet interface may be named "eth0" and have the
  54:  * address 192.168.1.101 assigned to it.
  55:  *
  56:  * @author Michael Koch (konqueror@gmx.de)
  57:  * @since 1.4
  58:  */
  59: public final class NetworkInterface
  60: {
  61:   private String name;
  62:   private Vector<InetAddress> inetAddresses;
  63: 
  64:   NetworkInterface(String name, InetAddress address)
  65:   {
  66:     this.name = name;
  67:     this.inetAddresses = new Vector(1, 1);
  68:     this.inetAddresses.add(address);
  69:   }
  70: 
  71:   NetworkInterface(String name, InetAddress[] addresses)
  72:   {
  73:     this.name = name;
  74:     this.inetAddresses = new Vector(addresses.length, 1);
  75: 
  76:     for (int i = 0; i < addresses.length; i++)
  77:       this.inetAddresses.add(addresses[i]);
  78:   }
  79: 
  80:   /**
  81:    * Returns the name of the network interface
  82:    *
  83:    * @return The name of the interface.
  84:    */
  85:   public String getName()
  86:   {
  87:     return name;
  88:   }
  89: 
  90:   /**
  91:    * Returns all available addresses of the network interface
  92:    *
  93:    * If a @see SecurityManager is available all addresses are checked
  94:    * with @see SecurityManager::checkConnect() if they are available.
  95:    * Only <code>InetAddresses</code> are returned where the security manager
  96:    * doesn't throw an exception.
  97:    *
  98:    * @return An enumeration of all addresses.
  99:    */
 100:   public Enumeration<InetAddress> getInetAddresses()
 101:   {
 102:     SecurityManager s = System.getSecurityManager();
 103: 
 104:     if (s == null)
 105:       return inetAddresses.elements();
 106: 
 107:     Vector<InetAddress> tmpInetAddresses = new Vector<InetAddress>(1, 1);
 108: 
 109:     for (Enumeration<InetAddress> addresses = inetAddresses.elements();
 110:          addresses.hasMoreElements();)
 111:       {
 112:     InetAddress addr = addresses.nextElement();
 113:     try
 114:       {
 115:         s.checkConnect(addr.getHostAddress(), 58000);
 116:         tmpInetAddresses.add(addr);
 117:       }
 118:     catch (SecurityException e)
 119:       {
 120:         // Ignore.
 121:       }
 122:       }
 123: 
 124:     return tmpInetAddresses.elements();
 125:   }
 126: 
 127:   /**
 128:    * Returns the display name of the interface
 129:    *
 130:    * @return The display name of the interface
 131:    */
 132:   public String getDisplayName()
 133:   {
 134:     return name;
 135:   }
 136: 
 137:   /**
 138:    * Returns an network interface by name
 139:    *
 140:    * @param name The name of the interface to return
 141:    * 
 142:    * @return a <code>NetworkInterface</code> object representing the interface,
 143:    * or null if there is no interface with that name.
 144:    *
 145:    * @exception SocketException If an error occurs
 146:    * @exception NullPointerException If the specified name is null
 147:    */
 148:   public static NetworkInterface getByName(String name)
 149:     throws SocketException
 150:   {
 151:     for (Enumeration e = getNetworkInterfaces(); e.hasMoreElements();)
 152:       {
 153:     NetworkInterface tmp = (NetworkInterface) e.nextElement();
 154: 
 155:     if (name.equals(tmp.getName()))
 156:       return tmp;
 157:       }
 158: 
 159:     // No interface with the given name found.
 160:     return null;
 161:   }
 162: 
 163:   /**
 164:    * Return a network interface by its address
 165:    *
 166:    * @param addr The address of the interface to return
 167:    *
 168:    * @return the interface, or <code>null</code> if none found
 169:    *
 170:    * @exception SocketException If an error occurs
 171:    * @exception NullPointerException If the specified addess is null
 172:    */
 173:   public static NetworkInterface getByInetAddress(InetAddress addr)
 174:     throws SocketException
 175:   {
 176:     for (Enumeration interfaces = getNetworkInterfaces();
 177:          interfaces.hasMoreElements();)
 178:       {
 179:     NetworkInterface tmp = (NetworkInterface) interfaces.nextElement();
 180: 
 181:     for (Enumeration addresses = tmp.inetAddresses.elements();
 182:          addresses.hasMoreElements();)
 183:       {
 184:         if (addr.equals((InetAddress) addresses.nextElement()))
 185:           return tmp;
 186:       }
 187:       }
 188: 
 189:     throw new SocketException("no network interface is bound to such an IP address");
 190:   }
 191: 
 192:   static private Collection condense(Collection interfaces) 
 193:   {
 194:     final Map condensed = new HashMap();
 195: 
 196:     final Iterator interfs = interfaces.iterator();
 197:     while (interfs.hasNext()) {
 198: 
 199:       final NetworkInterface face = (NetworkInterface) interfs.next();
 200:       final String name = face.getName();
 201:       
 202:       if (condensed.containsKey(name))
 203:     {
 204:       final NetworkInterface conface = (NetworkInterface) condensed.get(name);
 205:       if (!conface.inetAddresses.containsAll(face.inetAddresses))
 206:         {
 207:           final Iterator faceAddresses = face.inetAddresses.iterator();
 208:           while (faceAddresses.hasNext())
 209:         {
 210:           final InetAddress faceAddress = (InetAddress) faceAddresses.next();
 211:           if (!conface.inetAddresses.contains(faceAddress))
 212:             {
 213:               conface.inetAddresses.add(faceAddress);
 214:             }
 215:         }
 216:         }
 217:     }
 218:       else
 219:     {
 220:       condensed.put(name, face);
 221:     }
 222:     }
 223: 
 224:     return condensed.values();
 225:   }
 226: 
 227:   /**
 228:    * Return an <code>Enumeration</code> of all available network interfaces
 229:    *
 230:    * @return all interfaces
 231:    * 
 232:    * @exception SocketException If an error occurs
 233:    */
 234:   public static Enumeration<NetworkInterface> getNetworkInterfaces()
 235:     throws SocketException
 236:   {
 237:     Vector<NetworkInterface> networkInterfaces =
 238:       VMNetworkInterface.getInterfaces();
 239: 
 240:     if (networkInterfaces.isEmpty())
 241:       return null;
 242: 
 243:     Collection condensed = condense(networkInterfaces);
 244: 
 245:     return Collections.enumeration(condensed);
 246:   }
 247: 
 248:   /**
 249:    * Checks if the current instance is equal to obj
 250:    *
 251:    * @param obj The object to compare with
 252:    *
 253:    * @return <code>true</code> if equal, <code>false</code> otherwise
 254:    */
 255:   public boolean equals(Object obj)
 256:   {
 257:     if (! (obj instanceof NetworkInterface))
 258:       return false;
 259: 
 260:     NetworkInterface tmp = (NetworkInterface) obj;
 261: 
 262:     return (name.equals(tmp.name) && inetAddresses.equals(tmp.inetAddresses));
 263:   }
 264: 
 265:   /**
 266:    * Returns the hashcode of the current instance
 267:    *
 268:    * @return the hashcode
 269:    */
 270:   public int hashCode()
 271:   {
 272:     // FIXME: hash correctly
 273:     return name.hashCode() + inetAddresses.hashCode();
 274:   }
 275: 
 276:   /**
 277:    * Returns a string representation of the interface
 278:    *
 279:    * @return the string
 280:    */
 281:   public String toString()
 282:   {
 283:     // FIXME: check if this is correct
 284:     String result;
 285:     String separator = System.getProperty("line.separator");
 286: 
 287:     result =
 288:       "name: " + getDisplayName() + " (" + getName() + ") addresses:"
 289:       + separator;
 290: 
 291:     for (Enumeration e = inetAddresses.elements(); e.hasMoreElements();)
 292:       {
 293:     InetAddress address = (InetAddress) e.nextElement();
 294:     result += address.toString() + ";" + separator;
 295:       }
 296: 
 297:     return result;
 298:   }
 299: }