content: /*
   * Copyright (C) 2014 The Android Open Source Project
   * Copyright (c) 2000, 2013, 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;
  import java.io.InvalidObjectException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.io.ObjectStreamException;
  import java.io.ObjectStreamField;
  
  /**
   *
   * This class implements an IP Socket Address (IP address + port number)
   * It can also be a pair (hostname + port number), in which case an attempt
   * will be made to resolve the hostname. If resolution fails then the address
   * is said to be <I>unresolved</I> but can still be used on some circumstances
   * like connecting through a proxy.
   * <p>
   * It provides an immutable object used by sockets for binding, connecting, or
   * as returned values.
   * <p>
   * The <i>wildcard</i> is a special local IP address. It usually means "any"
   * and can only be used for {@code bind} operations.
   *
   * @see Socket
   * @see ServerSocket
   * @since 1.4
   */
  public class InetSocketAddress
      extends SocketAddress
  {
      // Private implementation class pointed to by all public methods.
      private static class InetSocketAddressHolder {
          // The hostname of the Socket Address
          private String hostname;
          // The IP address of the Socket Address
          private InetAddress addr;
          // The port number of the Socket Address
          private int port;
  
          private InetSocketAddressHolder(String hostname, InetAddress addr, int port) {
              this.hostname = hostname;
              this.addr = addr;
              this.port = port;
          }
  
          private int getPort() {
              return port;
          }
  
          private InetAddress getAddress() {
              return addr;
          }
  
          private String getHostName() {
              if (hostname != null)
                  return hostname;
              if (addr != null)
                  return addr.getHostName();
              return null;
          }
  
          private String getHostString() {
              if (hostname != null)
                  return hostname;
              if (addr != null) {
                  if (addr.holder().getHostName() != null)
                      return addr.holder().getHostName();
                  else
                      return addr.getHostAddress();
              }
              return null;
          }
  
          private boolean isUnresolved() {
              return addr == null;
          }
  
          @Override
          public String toString() {
              if (isUnresolved()) {
                  return hostname + ":" + port;
              } else {
                  return addr.toString() + ":" + port;
              }
          }
  
          @Override
          public final boolean equals(Object obj) {
              if (obj == null || !(obj instanceof InetSocketAddressHolder))
                  return false;
              InetSocketAddressHolder that = (InetSocketAddressHolder)obj;
              boolean sameIP;
              if (addr != null)
                  sameIP = addr.equals(that.addr);
              else if (hostname != null)
                  sameIP = (that.addr == null) &&
                      hostname.equalsIgnoreCase(that.hostname);
              else
                  sameIP = (that.addr == null) && (that.hostname == null);
              return sameIP && (port == that.port);
          }
  
          @Override
          public final int hashCode() {
              if (addr != null)
                  return addr.hashCode() + port;
              if (hostname != null)
                  return hostname.toLowerCase().hashCode() + port;
              return port;
          }
      }
  
      private final transient InetSocketAddressHolder holder;
  
      private static final long serialVersionUID = 5076001401234631237L;
  
      private static int checkPort(int port) {
          if (port < 0 || port > 0xFFFF)
              throw new IllegalArgumentException("port out of range:" + port);
          return port;
      }
  
      private static String checkHost(String hostname) {
          if (hostname == null)
              throw new IllegalArgumentException("hostname can't be null");
          return hostname;
      }
  
      // BEGIN Android-added: InetSocketAddress() ctor used by IoBridge.
      /**
       * @hide internal use only
       */
      public InetSocketAddress() {
          // These will be filled in the native implementation of recvfrom.
          holder = new InetSocketAddressHolder(null, null, 0);
      }
      // END Android-added: InetSocketAddress() ctor used by IoBridge.
  
      /**
       * Creates a socket address where the IP address is the wildcard address
       * and the port number a specified value.
       * <p>
       * A valid port value is between 0 and 65535.
       * A port number of {@code zero} will let the system pick up an
       * ephemeral port in a {@code bind} operation.
       * <p>
       * @param   port    The port number
       * @throws IllegalArgumentException if the port parameter is outside the specified
       * range of valid port values.
       */
      public InetSocketAddress(int port) {
          // Android-changed: Defaults to IPv6.
          // this(InetAddress.anyLocalAddress(), port);
          this((InetAddress)null, port);
      }
  
      /**
       *
       * Creates a socket address from an IP address and a port number.
       * <p>
       * A valid port value is between 0 and 65535.
       * A port number of {@code zero} will let the system pick up an
       * ephemeral port in a {@code bind} operation.
       * <P>
       * A {@code null} address will assign the <i>wildcard</i> address.
       * <p>
       * @param   addr    The IP address
       * @param   port    The port number
       * @throws IllegalArgumentException if the port parameter is outside the specified
       * range of valid port values.
       */
      public InetSocketAddress(InetAddress addr, int port) {
          holder = new InetSocketAddressHolder(
                          null,
                          // Android-changed: Defaults to IPv6 if addr is null.
                          // addr == null ? InetAddress.anyLocalAddress() : addr,
                          addr == null ? Inet6Address.ANY : addr,
                          checkPort(port));
      }
  
      /**
       *
       * Creates a socket address from a hostname and a port number.
       * <p>
       * An attempt will be made to resolve the hostname into an InetAddress.
       * If that attempt fails, the address will be flagged as <I>unresolved</I>.
       * <p>
       * If there is a security manager, its {@code checkConnect} method
       * is called with the host name as its argument to check the permission
       * to resolve it. This could result in a SecurityException.
       * <P>
       * A valid port value is between 0 and 65535.
       * A port number of {@code zero} will let the system pick up an
       * ephemeral port in a {@code bind} operation.
       * <P>
       * @param   hostname the Host name
       * @param   port    The port number
       * @throws IllegalArgumentException if the port parameter is outside the range
       * of valid port values, or if the hostname parameter is <TT>null</TT>.
       * @throws SecurityException if a security manager is present and
       *                           permission to resolve the host name is
       *                           denied.
       * @see     #isUnresolved()
       */
      public InetSocketAddress(String hostname, int port) {
          checkHost(hostname);
          InetAddress addr = null;
          String host = null;
          try {
              addr = InetAddress.getByName(hostname);
          } catch(UnknownHostException e) {
              host = hostname;
          }
          holder = new InetSocketAddressHolder(host, addr, checkPort(port));
      }
  
      // private constructor for creating unresolved instances
      private InetSocketAddress(int port, String hostname) {
          holder = new InetSocketAddressHolder(hostname, null, port);
      }
  
      /**
       *
       * Creates an unresolved socket address from a hostname and a port number.
       * <p>
       * No attempt will be made to resolve the hostname into an InetAddress.
       * The address will be flagged as <I>unresolved</I>.
       * <p>
       * A valid port value is between 0 and 65535.
       * A port number of {@code zero} will let the system pick up an
       * ephemeral port in a {@code bind} operation.
       * <P>
       * @param   host    the Host name
       * @param   port    The port number
       * @throws IllegalArgumentException if the port parameter is outside
       *                  the range of valid port values, or if the hostname
       *                  parameter is <TT>null</TT>.
       * @see     #isUnresolved()
       * @return  a {@code InetSocketAddress} representing the unresolved
       *          socket address
       * @since 1.5
       */
      public static InetSocketAddress createUnresolved(String host, int port) {
          return new InetSocketAddress(checkPort(port), checkHost(host));
      }
  
      /**
       * @serialField hostname String
       * @serialField addr InetAddress
       * @serialField port int
       */
      private static final ObjectStreamField[] serialPersistentFields = {
           new ObjectStreamField("hostname", String.class),
           new ObjectStreamField("addr", InetAddress.class),
           new ObjectStreamField("port", int.class)};
  
      private void writeObject(ObjectOutputStream out)
          throws IOException
      {
          // Don't call defaultWriteObject()
           ObjectOutputStream.PutField pfields = out.putFields();
           pfields.put("hostname", holder.hostname);
           pfields.put("addr", holder.addr);
           pfields.put("port", holder.port);
           out.writeFields();
       }
  
      private void readObject(ObjectInputStream in)
          throws IOException, ClassNotFoundException
      {
          // Don't call defaultReadObject()
          ObjectInputStream.GetField oisFields = in.readFields();
          final String oisHostname = (String)oisFields.get("hostname", null);
          final InetAddress oisAddr = (InetAddress)oisFields.get("addr", null);
          final int oisPort = oisFields.get("port", -1);
  
          // Check that our invariants are satisfied
          checkPort(oisPort);
          if (oisHostname == null && oisAddr == null)
              throw new InvalidObjectException("hostname and addr " +
                                               "can't both be null");
  
          InetSocketAddressHolder h = new InetSocketAddressHolder(oisHostname,
                                                                  oisAddr,
                                                                  oisPort);
          UNSAFE.putObject(this, FIELDS_OFFSET, h);
      }
  
      private void readObjectNoData()
          throws ObjectStreamException
      {
          throw new InvalidObjectException("Stream data required");
      }
  
      private static final long FIELDS_OFFSET;
      private static final sun.misc.Unsafe UNSAFE;
      static {
          try {
              sun.misc.Unsafe unsafe = sun.misc.Unsafe.getUnsafe();
              FIELDS_OFFSET = unsafe.objectFieldOffset(
                      InetSocketAddress.class.getDeclaredField("holder"));
              UNSAFE = unsafe;
          } catch (ReflectiveOperationException e) {
              throw new Error(e);
          }
      }
  
      /**
       * Gets the port number.
       *
       * @return the port number.
       */
      public final int getPort() {
          return holder.getPort();
      }
  
      /**
       *
       * Gets the {@code InetAddress}.
       *
       * @return the InetAdress or {@code null} if it is unresolved.
       */
      public final InetAddress getAddress() {
          return holder.getAddress();
      }
  
      /**
       * Gets the {@code hostname}.
       * Note: This method may trigger a name service reverse lookup if the
       * address was created with a literal IP address.
       *
       * @return  the hostname part of the address.
       */
      public final String getHostName() {
          return holder.getHostName();
      }
  
      /**
       * Returns the hostname, or the String form of the address if it
       * doesn't have a hostname (it was created using a literal).
       * This has the benefit of <b>not</b> attempting a reverse lookup.
       *
       * @return the hostname, or String representation of the address.
       * @since 1.7
       */
      public final String getHostString() {
          return holder.getHostString();
      }
  
      /**
       * Checks whether the address has been resolved or not.
       *
       * @return {@code true} if the hostname couldn't be resolved into
       *          an {@code InetAddress}.
       */
      public final boolean isUnresolved() {
          return holder.isUnresolved();
      }
  
      /**
       * Constructs a string representation of this InetSocketAddress.
       * This String is constructed by calling toString() on the InetAddress
       * and concatenating the port number (with a colon). If the address
       * is unresolved then the part before the colon will only contain the hostname.
       *
       * @return  a string representation of this object.
       */
      @Override
      public String toString() {
          return holder.toString();
      }
  
      /**
       * Compares this object against the specified object.
       * The result is {@code true} if and only if the argument is
       * not {@code null} and it represents the same address as
       * this object.
       * <p>
       * Two instances of {@code InetSocketAddress} represent the same
       * address if both the InetAddresses (or hostnames if it is unresolved) and port
       * numbers are equal.
       * If both addresses are unresolved, then the hostname and the port number
       * are compared.
       *
       * Note: Hostnames are case insensitive. e.g. "FooBar" and "foobar" are
       * considered equal.
       *
       * @param   obj   the object to compare against.
       * @return  {@code true} if the objects are the same;
       *          {@code false} otherwise.
       * @see InetAddress#equals(Object)
       */
      @Override
      public final boolean equals(Object obj) {
          if (obj == null || !(obj instanceof InetSocketAddress))
              return false;
          return holder.equals(((InetSocketAddress) obj).holder);
      }
  
      /**
       * Returns a hashcode for this socket address.
       *
       * @return  a hash code value for this socket address.
       */
      @Override
      public final int hashCode() {
          return holder.hashCode();
      }
  }
  