1. /*

  2.  * @(#)Inet4AddressImpl.java	1.4 03/12/19

  3.  *

  4.  * Copyright 2004 Sun Microsystems, Inc. All rights reserved.

  5.  * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.

  6.  */

  7. package java.net;

  8. import java.io.IOException;

  9. 

  10. /*

  11.  * Package private implementation of InetAddressImpl for IPv4.

  12.  *

  13.  * @since 1.4

  14.  */

  15. class Inet4AddressImpl implements InetAddressImpl {

  16.     public native String getLocalHostName() throws UnknownHostException;

  17.     public native byte[][]

  18.         lookupAllHostAddr(String hostname) throws UnknownHostException;

  19.     public native String getHostByAddr(byte[] addr) throws UnknownHostException;

  20.     private native boolean isReachable0(byte[] addr, int timeout, byte[] ifaddr, int ttl) throws IOException;

  21. 

  22.     public synchronized InetAddress anyLocalAddress() {

  23.         if (anyLocalAddress == null) {

  24.             anyLocalAddress = new Inet4Address(); // {0x00,0x00,0x00,0x00}

  25.             anyLocalAddress.hostName = "0.0.0.0";

  26.         }

  27.         return anyLocalAddress;

  28.     }

  29. 

  30.     public synchronized InetAddress loopbackAddress() {

  31.         if (loopbackAddress == null) {

  32.             byte[] loopback = {0x7f,0x00,0x00,0x01};

  33.             loopbackAddress = new Inet4Address("localhost", loopback);

  34.         }

  35.         return loopbackAddress;

  36.     }

  37. 

  38.   public boolean isReachable(InetAddress addr, int timeout, NetworkInterface netif, int ttl) throws IOException {

  39.       byte[] ifaddr = null;

  40.       if (netif != null) {

  41. 	  /*

  42. 	   * Let's make sure we use an address of the proper family

  43. 	   */

  44. 	  java.util.Enumeration it = netif.getInetAddresses();

  45. 	  InetAddress inetaddr = null;

  46. 	  while (!(inetaddr instanceof Inet4Address) &&

  47. 		 it.hasMoreElements())

  48. 	      inetaddr = (InetAddress) it.nextElement();

  49. 	  if (inetaddr instanceof Inet4Address)

  50. 	      ifaddr = inetaddr.getAddress();

  51.       }

  52.       return isReachable0(addr.getAddress(), timeout, ifaddr, ttl);

  53.   }

  54.     private InetAddress      anyLocalAddress;

  55.     private InetAddress      loopbackAddress;

  56. }

  57.