netinterface.java

Vyger offers a D & D and Rogue-like environment in a graphical online roleplay game.

/*
 * Light And Shadow. A Persistent Universe based on Robert Jordan's Wheel of Time Books.
 * Copyright (C) 2001-2002 WOTLAS Team
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */


package wotlas.libs.net.utils;

import java.net.*;
import java.util.Enumeration;

import wotlas.utils.Debug;

/**
 * A class that provides static methods to handle network interfaces via Java 1.4's
 * NetworkInterface.
 *
 * @author aldiss
 */

public class NetInterface {

 /*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/

   /** We return the names of all the network interfaces of this machine.
    * @return itf names, an empty array if none
    */
     static public String[] getInterfaceNames() {
       try{
         String names[] = new String[ getInterfaceNumber() ];
         Enumeration e = NetworkInterface.getNetworkInterfaces();

         int nb=0;

         while( e.hasMoreElements() ) {
                NetworkInterface ni = (NetworkInterface) e.nextElement();
                names[nb] = ni.getName();
                nb++;
         }
         
         return names;
       }catch(Throwable se) {
         Debug.signal(Debug.ERROR, null, ""+se );
         return new String[0];
       }
     }

 /*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/

   /** We return the number of network interfaces of this machine.
    * @return nb of interfaces
    */
     static public int getInterfaceNumber() {
       try{
         Enumeration e = NetworkInterface.getNetworkInterfaces();
         int nb=0;

         while( e.hasMoreElements() ) {
                e.nextElement();
                nb++;
         }

         return nb;
       }catch(Throwable se) {
         Debug.signal(Debug.ERROR, null, ""+se );
         return 0;
       }
     }

 /*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/

   /** We return the number of network addresses for the given interface name on this machine.
    * @param itfName name of the network interface
    * @return nb of addresses, 0 if none or if the itf is not found
    */
     static public int getAddressesNumber( String itfName ) {
       try{
         NetworkInterface ni = NetworkInterface.getByName( itfName );

         if(ni==null)
            return 0;

         Enumeration e = ni.getInetAddresses();
         int nb=0;

         while( e.hasMoreElements() ) {
                e.nextElement();
                nb++;
         }

         return nb;
       }catch(Throwable se) {
         Debug.signal(Debug.ERROR, null, ""+se );
         return 0;
       }
     }

 /*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/

   /** To get all the addresses of a specified interface.
    *  @param itfName name of the network interface
    *  @return all the IP address of the given interface, an empty array if none
    */
     public static String[] getInterfaceAddresses( String itfName ) {

       try{
         String names[] = new String[ getAddressesNumber(itfName) ];

         if(names.length==0)
            return names;

         NetworkInterface ni = NetworkInterface.getByName( itfName );
         Enumeration e = ni.getInetAddresses();
         int nb=0;

         while( e.hasMoreElements() ) {
                InetAddress in = (InetAddress) e.nextElement();
                names[nb] = in.getHostAddress();
                nb++;
         }
         
         return names;
       }catch(Throwable se) {
         Debug.signal(Debug.ERROR, null, ""+se );
         return new String[0];
       }
     }

 /*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/

   /** To get the description of an interface.
    *  @param itfName name of the network interface
    *  @return a description of the interface, if available.
    */
     public static String getInterfaceDescription( String itfName ) {
       try{
          NetworkInterface ni = NetworkInterface.getByName( itfName );

          if( ni==null )
             return "[Error: interface not found !]";

          return ni.getDisplayName();
       }catch(Throwable se) {
          Debug.signal(Debug.ERROR, null, ""+se );
          return "[Error: "+se.getMessage()+"]";
       }
     }

 /*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/

   /** Returns all the available network information of this machine.
    */
     public static String getNetworkInfo() {
        String itf[] = getInterfaceNames();
        StringBuffer buf = new StringBuffer("Network Interfaces\n------------------\n\n");

        for( int i=0; i<itf.length; i++ ) {
             buf.append("  "+i+" - "+itf[i]+"\n");
             buf.append("      Descr. : "+getInterfaceDescription( itf[i] )+"\n" );
             buf.append("      IP adr : \n");
             
             String ip[] = getInterfaceAddresses( itf[i] );

             for( int j=0; j<ip.length; j++ )
                  buf.append("           "+j+" - "+ip[j]+"\n");

             buf.append("\n");             
        }
        
        return buf.toString();
     }

 /*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/

}