/* * Copyright (c) 2002, 2005, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */package java.net;import java.io.IOException; /* * Package private implementation of InetAddressImpl for IPv4. * * @since 1.4 */class Inet4AddressImpl implements InetAddressImpl {    public native String getLocalHostName() throws UnknownHostException;    public native InetAddress[]        lookupAllHostAddr(String hostname) throws UnknownHostException;    public native String getHostByAddr(byte[] addr) throws UnknownHostException;    private native boolean isReachable0(byte[] addr, int timeout, byte[] ifaddr, int ttl) throws IOException;     public synchronized InetAddress anyLocalAddress() {        if (anyLocalAddress == null) {            anyLocalAddress = new Inet4Address(); // {0x00,0x00,0x00,0x00}            anyLocalAddress.hostName = "0.0.0.0";        }        return anyLocalAddress;    }     public synchronized InetAddress loopbackAddress() {        if (loopbackAddress == null) {            byte[] loopback = {0x7f,0x00,0x00,0x01};            loopbackAddress = new Inet4Address("localhost", loopback);        }        return loopbackAddress;    }   public boolean isReachable(InetAddress addr, int timeout, NetworkInterface netif, int ttl) throws IOException {      byte[] ifaddr = null;      if (netif != null) {          /*           * Let's make sure we use an address of the proper family           */          java.util.Enumeration it = netif.getInetAddresses();          InetAddress inetaddr = null;          while (!(inetaddr instanceof Inet4Address) &&                 it.hasMoreElements())              inetaddr = (InetAddress) it.nextElement();          if (inetaddr instanceof Inet4Address)              ifaddr = inetaddr.getAddress();      }      return isReachable0(addr.getAddress(), timeout, ifaddr, ttl);  }    private InetAddress      anyLocalAddress;    private InetAddress      loopbackAddress;}