|  | /* | 
|  | * Copyright (c) 1995, 2014, 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.util.Enumeration; | 
|  |  | 
|  | // Android-changed: Updated example code to handle non-ASCII characters | 
|  | /** | 
|  | * The multicast datagram socket class is useful for sending | 
|  | * and receiving IP multicast packets.  A MulticastSocket is | 
|  | * a (UDP) DatagramSocket, with additional capabilities for | 
|  | * joining "groups" of other multicast hosts on the internet. | 
|  | * <P> | 
|  | * A multicast group is specified by a class D IP address | 
|  | * and by a standard UDP port number. Class D IP addresses | 
|  | * are in the range <CODE>224.0.0.0</CODE> to <CODE>239.255.255.255</CODE>, | 
|  | * inclusive. The address 224.0.0.0 is reserved and should not be used. | 
|  | * <P> | 
|  | * One would join a multicast group by first creating a MulticastSocket | 
|  | * with the desired port, then invoking the | 
|  | * <CODE>joinGroup(InetAddress groupAddr)</CODE> | 
|  | * method: | 
|  | * <PRE> | 
|  | * // join a Multicast group and send the group salutations | 
|  | * ... | 
|  | * String msg = "Hello"; | 
|  | * InetAddress group = InetAddress.getByName("228.5.6.7"); | 
|  | * MulticastSocket s = new MulticastSocket(6789); | 
|  | * s.joinGroup(group); | 
|  | * byte[] bytes = msg.getBytes(StandardCharsets.UTF_8); | 
|  | * DatagramPacket hi = new DatagramPacket(bytes, bytes.length, | 
|  | *                             group, 6789); | 
|  | * s.send(hi); | 
|  | * // get their responses! | 
|  | * byte[] buf = new byte[1000]; | 
|  | * DatagramPacket recv = new DatagramPacket(buf, buf.length); | 
|  | * s.receive(recv); | 
|  | * ... | 
|  | * // OK, I'm done talking - leave the group... | 
|  | * s.leaveGroup(group); | 
|  | * </PRE> | 
|  | * | 
|  | * When one sends a message to a multicast group, <B>all</B> subscribing | 
|  | * recipients to that host and port receive the message (within the | 
|  | * time-to-live range of the packet, see below).  The socket needn't | 
|  | * be a member of the multicast group to send messages to it. | 
|  | * <P> | 
|  | * When a socket subscribes to a multicast group/port, it receives | 
|  | * datagrams sent by other hosts to the group/port, as do all other | 
|  | * members of the group and port.  A socket relinquishes membership | 
|  | * in a group by the leaveGroup(InetAddress addr) method.  <B> | 
|  | * Multiple MulticastSocket's</B> may subscribe to a multicast group | 
|  | * and port concurrently, and they will all receive group datagrams. | 
|  | * <P> | 
|  | * Currently applets are not allowed to use multicast sockets. | 
|  | * | 
|  | * @author Pavani Diwanji | 
|  | * @since  JDK1.1 | 
|  | */ | 
|  | public | 
|  | class MulticastSocket extends DatagramSocket { | 
|  |  | 
|  | /** | 
|  | * Used on some platforms to record if an outgoing interface | 
|  | * has been set for this socket. | 
|  | */ | 
|  | private boolean interfaceSet; | 
|  |  | 
|  | /** | 
|  | * Create a multicast socket. | 
|  | * | 
|  | * <p>If there is a security manager, | 
|  | * its {@code checkListen} method is first called | 
|  | * with 0 as its argument to ensure the operation is allowed. | 
|  | * This could result in a SecurityException. | 
|  | * <p> | 
|  | * When the socket is created the | 
|  | * {@link DatagramSocket#setReuseAddress(boolean)} method is | 
|  | * called to enable the SO_REUSEADDR socket option. | 
|  | * | 
|  | * @exception IOException if an I/O exception occurs | 
|  | * while creating the MulticastSocket | 
|  | * @exception  SecurityException  if a security manager exists and its | 
|  | *             {@code checkListen} method doesn't allow the operation. | 
|  | * @see SecurityManager#checkListen | 
|  | * @see java.net.DatagramSocket#setReuseAddress(boolean) | 
|  | */ | 
|  | public MulticastSocket() throws IOException { | 
|  | this(new InetSocketAddress(0)); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Create a multicast socket and bind it to a specific port. | 
|  | * | 
|  | * <p>If there is a security manager, | 
|  | * its {@code checkListen} method is first called | 
|  | * with the {@code port} argument | 
|  | * as its argument to ensure the operation is allowed. | 
|  | * This could result in a SecurityException. | 
|  | * <p> | 
|  | * When the socket is created the | 
|  | * {@link DatagramSocket#setReuseAddress(boolean)} method is | 
|  | * called to enable the SO_REUSEADDR socket option. | 
|  | * | 
|  | * @param port port to use | 
|  | * @exception IOException if an I/O exception occurs | 
|  | * while creating the MulticastSocket | 
|  | * @exception  SecurityException  if a security manager exists and its | 
|  | *             {@code checkListen} method doesn't allow the operation. | 
|  | * @see SecurityManager#checkListen | 
|  | * @see java.net.DatagramSocket#setReuseAddress(boolean) | 
|  | */ | 
|  | public MulticastSocket(int port) throws IOException { | 
|  | this(new InetSocketAddress(port)); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Create a MulticastSocket bound to the specified socket address. | 
|  | * <p> | 
|  | * Or, if the address is {@code null}, create an unbound socket. | 
|  | * | 
|  | * <p>If there is a security manager, | 
|  | * its {@code checkListen} method is first called | 
|  | * with the SocketAddress port as its argument to ensure the operation is allowed. | 
|  | * This could result in a SecurityException. | 
|  | * <p> | 
|  | * When the socket is created the | 
|  | * {@link DatagramSocket#setReuseAddress(boolean)} method is | 
|  | * called to enable the SO_REUSEADDR socket option. | 
|  | * | 
|  | * @param bindaddr Socket address to bind to, or {@code null} for | 
|  | *                 an unbound socket. | 
|  | * @exception IOException if an I/O exception occurs | 
|  | * while creating the MulticastSocket | 
|  | * @exception  SecurityException  if a security manager exists and its | 
|  | *             {@code checkListen} method doesn't allow the operation. | 
|  | * @see SecurityManager#checkListen | 
|  | * @see java.net.DatagramSocket#setReuseAddress(boolean) | 
|  | * | 
|  | * @since 1.4 | 
|  | */ | 
|  | public MulticastSocket(SocketAddress bindaddr) throws IOException { | 
|  | super((SocketAddress) null); | 
|  |  | 
|  | // Enable SO_REUSEADDR before binding | 
|  | setReuseAddress(true); | 
|  |  | 
|  | if (bindaddr != null) { | 
|  | try { | 
|  | bind(bindaddr); | 
|  | } finally { | 
|  | if (!isBound()) | 
|  | close(); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * The lock on the socket's TTL. This is for set/getTTL and | 
|  | * send(packet,ttl). | 
|  | */ | 
|  | private Object ttlLock = new Object(); | 
|  |  | 
|  | /** | 
|  | * The lock on the socket's interface - used by setInterface | 
|  | * and getInterface | 
|  | */ | 
|  | private Object infLock = new Object(); | 
|  |  | 
|  | /** | 
|  | * The "last" interface set by setInterface on this MulticastSocket | 
|  | */ | 
|  | private InetAddress infAddress = null; | 
|  |  | 
|  |  | 
|  | /** | 
|  | * Set the default time-to-live for multicast packets sent out | 
|  | * on this {@code MulticastSocket} in order to control the | 
|  | * scope of the multicasts. | 
|  | * | 
|  | * <p>The ttl is an <b>unsigned</b> 8-bit quantity, and so <B>must</B> be | 
|  | * in the range {@code 0 <= ttl <= 0xFF }. | 
|  | * | 
|  | * @param ttl the time-to-live | 
|  | * @exception IOException if an I/O exception occurs | 
|  | * while setting the default time-to-live value | 
|  | * @deprecated use the setTimeToLive method instead, which uses | 
|  | * <b>int</b> instead of <b>byte</b> as the type for ttl. | 
|  | * @see #getTTL() | 
|  | */ | 
|  | @Deprecated | 
|  | public void setTTL(byte ttl) throws IOException { | 
|  | if (isClosed()) | 
|  | throw new SocketException("Socket is closed"); | 
|  | getImpl().setTTL(ttl); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Set the default time-to-live for multicast packets sent out | 
|  | * on this {@code MulticastSocket} in order to control the | 
|  | * scope of the multicasts. | 
|  | * | 
|  | * <P> The ttl <B>must</B> be in the range {@code  0 <= ttl <= | 
|  | * 255} or an {@code IllegalArgumentException} will be thrown. | 
|  | * Multicast packets sent with a TTL of {@code 0} are not transmitted | 
|  | * on the network but may be delivered locally. | 
|  | * | 
|  | * @param  ttl | 
|  | *         the time-to-live | 
|  | * | 
|  | * @throws  IOException | 
|  | *          if an I/O exception occurs while setting the | 
|  | *          default time-to-live value | 
|  | * | 
|  | * @see #getTimeToLive() | 
|  | */ | 
|  | public void setTimeToLive(int ttl) throws IOException { | 
|  | if (ttl < 0 || ttl > 255) { | 
|  | throw new IllegalArgumentException("ttl out of range"); | 
|  | } | 
|  | if (isClosed()) | 
|  | throw new SocketException("Socket is closed"); | 
|  | getImpl().setTimeToLive(ttl); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Get the default time-to-live for multicast packets sent out on | 
|  | * the socket. | 
|  | * | 
|  | * @exception IOException if an I/O exception occurs | 
|  | * while getting the default time-to-live value | 
|  | * @return the default time-to-live value | 
|  | * @deprecated use the getTimeToLive method instead, which returns | 
|  | * an <b>int</b> instead of a <b>byte</b>. | 
|  | * @see #setTTL(byte) | 
|  | */ | 
|  | @Deprecated | 
|  | public byte getTTL() throws IOException { | 
|  | if (isClosed()) | 
|  | throw new SocketException("Socket is closed"); | 
|  | return getImpl().getTTL(); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Get the default time-to-live for multicast packets sent out on | 
|  | * the socket. | 
|  | * @exception IOException if an I/O exception occurs while | 
|  | * getting the default time-to-live value | 
|  | * @return the default time-to-live value | 
|  | * @see #setTimeToLive(int) | 
|  | */ | 
|  | public int getTimeToLive() throws IOException { | 
|  | if (isClosed()) | 
|  | throw new SocketException("Socket is closed"); | 
|  | return getImpl().getTimeToLive(); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Joins a multicast group. Its behavior may be affected by | 
|  | * {@code setInterface} or {@code setNetworkInterface}. | 
|  | * | 
|  | * <p>If there is a security manager, this method first | 
|  | * calls its {@code checkMulticast} method | 
|  | * with the {@code mcastaddr} argument | 
|  | * as its argument. | 
|  | * | 
|  | * @param mcastaddr is the multicast address to join | 
|  | * | 
|  | * @exception IOException if there is an error joining | 
|  | * or when the address is not a multicast address. | 
|  | * @exception  SecurityException  if a security manager exists and its | 
|  | * {@code checkMulticast} method doesn't allow the join. | 
|  | * | 
|  | * @see SecurityManager#checkMulticast(InetAddress) | 
|  | */ | 
|  | public void joinGroup(InetAddress mcastaddr) throws IOException { | 
|  | if (isClosed()) { | 
|  | throw new SocketException("Socket is closed"); | 
|  | } | 
|  |  | 
|  | checkAddress(mcastaddr, "joinGroup"); | 
|  | SecurityManager security = System.getSecurityManager(); | 
|  | if (security != null) { | 
|  | security.checkMulticast(mcastaddr); | 
|  | } | 
|  |  | 
|  | if (!mcastaddr.isMulticastAddress()) { | 
|  | throw new SocketException("Not a multicast address"); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * required for some platforms where it's not possible to join | 
|  | * a group without setting the interface first. | 
|  | */ | 
|  | NetworkInterface defaultInterface = NetworkInterface.getDefault(); | 
|  |  | 
|  | if (!interfaceSet && defaultInterface != null) { | 
|  | setNetworkInterface(defaultInterface); | 
|  | } | 
|  |  | 
|  | getImpl().join(mcastaddr); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Leave a multicast group. Its behavior may be affected by | 
|  | * {@code setInterface} or {@code setNetworkInterface}. | 
|  | * | 
|  | * <p>If there is a security manager, this method first | 
|  | * calls its {@code checkMulticast} method | 
|  | * with the {@code mcastaddr} argument | 
|  | * as its argument. | 
|  | * | 
|  | * @param mcastaddr is the multicast address to leave | 
|  | * @exception IOException if there is an error leaving | 
|  | * or when the address is not a multicast address. | 
|  | * @exception  SecurityException  if a security manager exists and its | 
|  | * {@code checkMulticast} method doesn't allow the operation. | 
|  | * | 
|  | * @see SecurityManager#checkMulticast(InetAddress) | 
|  | */ | 
|  | public void leaveGroup(InetAddress mcastaddr) throws IOException { | 
|  | if (isClosed()) { | 
|  | throw new SocketException("Socket is closed"); | 
|  | } | 
|  |  | 
|  | checkAddress(mcastaddr, "leaveGroup"); | 
|  | SecurityManager security = System.getSecurityManager(); | 
|  | if (security != null) { | 
|  | security.checkMulticast(mcastaddr); | 
|  | } | 
|  |  | 
|  | if (!mcastaddr.isMulticastAddress()) { | 
|  | throw new SocketException("Not a multicast address"); | 
|  | } | 
|  |  | 
|  | getImpl().leave(mcastaddr); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Joins the specified multicast group at the specified interface. | 
|  | * | 
|  | * <p>If there is a security manager, this method first | 
|  | * calls its {@code checkMulticast} method | 
|  | * with the {@code mcastaddr} argument | 
|  | * as its argument. | 
|  | * | 
|  | * @param mcastaddr is the multicast address to join | 
|  | * @param netIf specifies the local interface to receive multicast | 
|  | *        datagram packets, or <i>null</i> to defer to the interface set by | 
|  | *       {@link MulticastSocket#setInterface(InetAddress)} or | 
|  | *       {@link MulticastSocket#setNetworkInterface(NetworkInterface)} | 
|  | * | 
|  | * @exception IOException if there is an error joining | 
|  | * or when the address is not a multicast address. | 
|  | * @exception  SecurityException  if a security manager exists and its | 
|  | * {@code checkMulticast} method doesn't allow the join. | 
|  | * @throws  IllegalArgumentException if mcastaddr is null or is a | 
|  | *          SocketAddress subclass not supported by this socket | 
|  | * | 
|  | * @see SecurityManager#checkMulticast(InetAddress) | 
|  | * @since 1.4 | 
|  | */ | 
|  | public void joinGroup(SocketAddress mcastaddr, NetworkInterface netIf) | 
|  | throws IOException { | 
|  | if (isClosed()) | 
|  | throw new SocketException("Socket is closed"); | 
|  |  | 
|  | if (mcastaddr == null || !(mcastaddr instanceof InetSocketAddress)) | 
|  | throw new IllegalArgumentException("Unsupported address type"); | 
|  |  | 
|  | if (oldImpl) | 
|  | throw new UnsupportedOperationException(); | 
|  |  | 
|  | checkAddress(((InetSocketAddress)mcastaddr).getAddress(), "joinGroup"); | 
|  | SecurityManager security = System.getSecurityManager(); | 
|  | if (security != null) { | 
|  | security.checkMulticast(((InetSocketAddress)mcastaddr).getAddress()); | 
|  | } | 
|  |  | 
|  | if (!((InetSocketAddress)mcastaddr).getAddress().isMulticastAddress()) { | 
|  | throw new SocketException("Not a multicast address"); | 
|  | } | 
|  |  | 
|  | getImpl().joinGroup(mcastaddr, netIf); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Leave a multicast group on a specified local interface. | 
|  | * | 
|  | * <p>If there is a security manager, this method first | 
|  | * calls its {@code checkMulticast} method | 
|  | * with the {@code mcastaddr} argument | 
|  | * as its argument. | 
|  | * | 
|  | * @param mcastaddr is the multicast address to leave | 
|  | * @param netIf specifies the local interface or <i>null</i> to defer | 
|  | *             to the interface set by | 
|  | *             {@link MulticastSocket#setInterface(InetAddress)} or | 
|  | *             {@link MulticastSocket#setNetworkInterface(NetworkInterface)} | 
|  | * @exception IOException if there is an error leaving | 
|  | * or when the address is not a multicast address. | 
|  | * @exception  SecurityException  if a security manager exists and its | 
|  | * {@code checkMulticast} method doesn't allow the operation. | 
|  | * @throws  IllegalArgumentException if mcastaddr is null or is a | 
|  | *          SocketAddress subclass not supported by this socket | 
|  | * | 
|  | * @see SecurityManager#checkMulticast(InetAddress) | 
|  | * @since 1.4 | 
|  | */ | 
|  | public void leaveGroup(SocketAddress mcastaddr, NetworkInterface netIf) | 
|  | throws IOException { | 
|  | if (isClosed()) | 
|  | throw new SocketException("Socket is closed"); | 
|  |  | 
|  | if (mcastaddr == null || !(mcastaddr instanceof InetSocketAddress)) | 
|  | throw new IllegalArgumentException("Unsupported address type"); | 
|  |  | 
|  | if (oldImpl) | 
|  | throw new UnsupportedOperationException(); | 
|  |  | 
|  | checkAddress(((InetSocketAddress)mcastaddr).getAddress(), "leaveGroup"); | 
|  | SecurityManager security = System.getSecurityManager(); | 
|  | if (security != null) { | 
|  | security.checkMulticast(((InetSocketAddress)mcastaddr).getAddress()); | 
|  | } | 
|  |  | 
|  | if (!((InetSocketAddress)mcastaddr).getAddress().isMulticastAddress()) { | 
|  | throw new SocketException("Not a multicast address"); | 
|  | } | 
|  |  | 
|  | getImpl().leaveGroup(mcastaddr, netIf); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Set the multicast network interface used by methods | 
|  | * whose behavior would be affected by the value of the | 
|  | * network interface. Useful for multihomed hosts. | 
|  | * @param inf the InetAddress | 
|  | * @exception SocketException if there is an error in | 
|  | * the underlying protocol, such as a TCP error. | 
|  | * @see #getInterface() | 
|  | */ | 
|  | public void setInterface(InetAddress inf) throws SocketException { | 
|  | if (isClosed()) { | 
|  | throw new SocketException("Socket is closed"); | 
|  | } | 
|  | checkAddress(inf, "setInterface"); | 
|  | synchronized (infLock) { | 
|  | getImpl().setOption(SocketOptions.IP_MULTICAST_IF, inf); | 
|  | infAddress = inf; | 
|  | interfaceSet = true; | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Retrieve the address of the network interface used for | 
|  | * multicast packets. | 
|  | * | 
|  | * @return An {@code InetAddress} representing | 
|  | *  the address of the network interface used for | 
|  | *  multicast packets. | 
|  | * | 
|  | * @exception SocketException if there is an error in | 
|  | * the underlying protocol, such as a TCP error. | 
|  | * | 
|  | * @see #setInterface(java.net.InetAddress) | 
|  | */ | 
|  | public InetAddress getInterface() throws SocketException { | 
|  | if (isClosed()) { | 
|  | throw new SocketException("Socket is closed"); | 
|  | } | 
|  | synchronized (infLock) { | 
|  | InetAddress ia = | 
|  | (InetAddress)getImpl().getOption(SocketOptions.IP_MULTICAST_IF); | 
|  |  | 
|  | /** | 
|  | * No previous setInterface or interface can be | 
|  | * set using setNetworkInterface | 
|  | */ | 
|  | if (infAddress == null) { | 
|  | return ia; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Same interface set with setInterface? | 
|  | */ | 
|  | if (ia.equals(infAddress)) { | 
|  | return ia; | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Different InetAddress from what we set with setInterface | 
|  | * so enumerate the current interface to see if the | 
|  | * address set by setInterface is bound to this interface. | 
|  | */ | 
|  | try { | 
|  | NetworkInterface ni = NetworkInterface.getByInetAddress(ia); | 
|  | Enumeration<InetAddress> addrs = ni.getInetAddresses(); | 
|  | while (addrs.hasMoreElements()) { | 
|  | InetAddress addr = addrs.nextElement(); | 
|  | if (addr.equals(infAddress)) { | 
|  | return infAddress; | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * No match so reset infAddress to indicate that the | 
|  | * interface has changed via means | 
|  | */ | 
|  | infAddress = null; | 
|  | return ia; | 
|  | } catch (Exception e) { | 
|  | return ia; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Specify the network interface for outgoing multicast datagrams | 
|  | * sent on this socket. | 
|  | * | 
|  | * @param netIf the interface | 
|  | * @exception SocketException if there is an error in | 
|  | * the underlying protocol, such as a TCP error. | 
|  | * @see #getNetworkInterface() | 
|  | * @since 1.4 | 
|  | */ | 
|  | public void setNetworkInterface(NetworkInterface netIf) | 
|  | throws SocketException { | 
|  |  | 
|  | synchronized (infLock) { | 
|  | getImpl().setOption(SocketOptions.IP_MULTICAST_IF2, netIf); | 
|  | infAddress = null; | 
|  | interfaceSet = true; | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Get the multicast network interface set. | 
|  | * | 
|  | * @exception SocketException if there is an error in | 
|  | * the underlying protocol, such as a TCP error. | 
|  | * @return the multicast {@code NetworkInterface} currently set | 
|  | * @see #setNetworkInterface(NetworkInterface) | 
|  | * @since 1.4 | 
|  | */ | 
|  | public NetworkInterface getNetworkInterface() throws SocketException { | 
|  | // Android-changed: Support Integer IP_MULTICAST_IF2 values for app compat. | 
|  | Integer niIndex | 
|  | = (Integer)getImpl().getOption(SocketOptions.IP_MULTICAST_IF2); | 
|  | if (niIndex == 0) { | 
|  | InetAddress[] addrs = new InetAddress[1]; | 
|  | addrs[0] = InetAddress.anyLocalAddress(); | 
|  | return new NetworkInterface(addrs[0].getHostName(), 0, addrs); | 
|  | } else { | 
|  | return NetworkInterface.getByIndex(niIndex); | 
|  | } | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Disable/Enable local loopback of multicast datagrams | 
|  | * The option is used by the platform's networking code as a hint | 
|  | * for setting whether multicast data will be looped back to | 
|  | * the local socket. | 
|  | * | 
|  | * <p>Because this option is a hint, applications that want to | 
|  | * verify what loopback mode is set to should call | 
|  | * {@link #getLoopbackMode()} | 
|  | * @param disable {@code true} to disable the LoopbackMode | 
|  | * @throws SocketException if an error occurs while setting the value | 
|  | * @since 1.4 | 
|  | * @see #getLoopbackMode | 
|  | */ | 
|  | public void setLoopbackMode(boolean disable) throws SocketException { | 
|  | getImpl().setOption(SocketOptions.IP_MULTICAST_LOOP, Boolean.valueOf(disable)); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Get the setting for local loopback of multicast datagrams. | 
|  | * | 
|  | * @throws SocketException  if an error occurs while getting the value | 
|  | * @return true if the LoopbackMode has been disabled | 
|  | * @since 1.4 | 
|  | * @see #setLoopbackMode | 
|  | */ | 
|  | public boolean getLoopbackMode() throws SocketException { | 
|  | return ((Boolean)getImpl().getOption(SocketOptions.IP_MULTICAST_LOOP)).booleanValue(); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * Sends a datagram packet to the destination, with a TTL (time- | 
|  | * to-live) other than the default for the socket.  This method | 
|  | * need only be used in instances where a particular TTL is desired; | 
|  | * otherwise it is preferable to set a TTL once on the socket, and | 
|  | * use that default TTL for all packets.  This method does <B>not | 
|  | * </B> alter the default TTL for the socket. Its behavior may be | 
|  | * affected by {@code setInterface}. | 
|  | * | 
|  | * <p>If there is a security manager, this method first performs some | 
|  | * security checks. First, if {@code p.getAddress().isMulticastAddress()} | 
|  | * is true, this method calls the | 
|  | * security manager's {@code checkMulticast} method | 
|  | * with {@code p.getAddress()} and {@code ttl} as its arguments. | 
|  | * If the evaluation of that expression is false, | 
|  | * this method instead calls the security manager's | 
|  | * {@code checkConnect} method with arguments | 
|  | * {@code p.getAddress().getHostAddress()} and | 
|  | * {@code p.getPort()}. Each call to a security manager method | 
|  | * could result in a SecurityException if the operation is not allowed. | 
|  | * | 
|  | * @param p is the packet to be sent. The packet should contain | 
|  | * the destination multicast ip address and the data to be sent. | 
|  | * One does not need to be the member of the group to send | 
|  | * packets to a destination multicast address. | 
|  | * @param ttl optional time to live for multicast packet. | 
|  | * default ttl is 1. | 
|  | * | 
|  | * @exception IOException is raised if an error occurs i.e | 
|  | * error while setting ttl. | 
|  | * @exception  SecurityException  if a security manager exists and its | 
|  | *             {@code checkMulticast} or {@code checkConnect} | 
|  | *             method doesn't allow the send. | 
|  | * | 
|  | * @deprecated Use the following code or its equivalent instead: | 
|  | *  ...... | 
|  | *  int ttl = mcastSocket.getTimeToLive(); | 
|  | *  mcastSocket.setTimeToLive(newttl); | 
|  | *  mcastSocket.send(p); | 
|  | *  mcastSocket.setTimeToLive(ttl); | 
|  | *  ...... | 
|  | * | 
|  | * @see DatagramSocket#send | 
|  | * @see DatagramSocket#receive | 
|  | * @see SecurityManager#checkMulticast(java.net.InetAddress, byte) | 
|  | * @see SecurityManager#checkConnect | 
|  | */ | 
|  | @Deprecated | 
|  | public void send(DatagramPacket p, byte ttl) | 
|  | throws IOException { | 
|  | if (isClosed()) | 
|  | throw new SocketException("Socket is closed"); | 
|  | checkAddress(p.getAddress(), "send"); | 
|  | synchronized(ttlLock) { | 
|  | synchronized(p) { | 
|  | if (connectState == ST_NOT_CONNECTED) { | 
|  | // Security manager makes sure that the multicast address | 
|  | // is allowed one and that the ttl used is less | 
|  | // than the allowed maxttl. | 
|  | SecurityManager security = System.getSecurityManager(); | 
|  | if (security != null) { | 
|  | if (p.getAddress().isMulticastAddress()) { | 
|  | security.checkMulticast(p.getAddress(), ttl); | 
|  | } else { | 
|  | security.checkConnect(p.getAddress().getHostAddress(), | 
|  | p.getPort()); | 
|  | } | 
|  | } | 
|  | } else { | 
|  | // we're connected | 
|  | InetAddress packetAddress = null; | 
|  | packetAddress = p.getAddress(); | 
|  | if (packetAddress == null) { | 
|  | p.setAddress(connectedAddress); | 
|  | p.setPort(connectedPort); | 
|  | } else if ((!packetAddress.equals(connectedAddress)) || | 
|  | p.getPort() != connectedPort) { | 
|  | throw new SecurityException("connected address and packet address" + | 
|  | " differ"); | 
|  | } | 
|  | } | 
|  | byte dttl = getTTL(); | 
|  | try { | 
|  | if (ttl != dttl) { | 
|  | // set the ttl | 
|  | getImpl().setTTL(ttl); | 
|  | } | 
|  | // call the datagram method to send | 
|  | getImpl().send(p); | 
|  | } finally { | 
|  | // set it back to default | 
|  | if (ttl != dttl) { | 
|  | getImpl().setTTL(dttl); | 
|  | } | 
|  | } | 
|  | } // synch p | 
|  | }  //synch ttl | 
|  | } //method | 
|  | } |