| /* |
| * Copyright (c) 2007, 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.nio.channels; |
| |
| import java.net.InetAddress; |
| import java.net.NetworkInterface; |
| import java.io.IOException; |
| import java.net.ProtocolFamily; // javadoc |
| import java.net.StandardProtocolFamily; // javadoc |
| import java.net.StandardSocketOptions; // javadoc |
| |
| /** |
| * A network channel that supports Internet Protocol (IP) multicasting. |
| * |
| * <p> IP multicasting is the transmission of IP datagrams to members of |
| * a <em>group</em> that is zero or more hosts identified by a single destination |
| * address. |
| * |
| * <p> In the case of a channel to an {@link StandardProtocolFamily#INET IPv4} socket, |
| * the underlying operating system supports <a href="http://www.ietf.org/rfc/rfc2236.txt"> |
| * <i>RFC 2236: Internet Group Management Protocol, Version 2 (IGMPv2)</i></a>. |
| * It may optionally support source filtering as specified by <a |
| * href="http://www.ietf.org/rfc/rfc3376.txt"> <i>RFC 3376: Internet Group |
| * Management Protocol, Version 3 (IGMPv3)</i></a>. |
| * For channels to an {@link StandardProtocolFamily#INET6 IPv6} socket, the equivalent |
| * standards are <a href="http://www.ietf.org/rfc/rfc2710.txt"> <i>RFC 2710: |
| * Multicast Listener Discovery (MLD) for IPv6</i></a> and <a |
| * href="http://www.ietf.org/rfc/rfc3810.txt"> <i>RFC 3810: Multicast Listener |
| * Discovery Version 2 (MLDv2) for IPv6</i></a>. |
| * |
| * <p> The {@link #join(InetAddress,NetworkInterface)} method is used to |
| * join a group and receive all multicast datagrams sent to the group. A channel |
| * may join several multicast groups and may join the same group on several |
| * {@link NetworkInterface interfaces}. Membership is dropped by invoking the {@link |
| * MembershipKey#drop drop} method on the returned {@link MembershipKey}. If the |
| * underlying platform supports source filtering then the {@link MembershipKey#block |
| * block} and {@link MembershipKey#unblock unblock} methods can be used to block or |
| * unblock multicast datagrams from particular source addresses. |
| * |
| * <p> The {@link #join(InetAddress,NetworkInterface,InetAddress)} method |
| * is used to begin receiving datagrams sent to a group whose source address matches |
| * a given source address. This method throws {@link UnsupportedOperationException} |
| * if the underlying platform does not support source filtering. Membership is |
| * <em>cumulative</em> and this method may be invoked again with the same group |
| * and interface to allow receiving datagrams from other source addresses. The |
| * method returns a {@link MembershipKey} that represents membership to receive |
| * datagrams from the given source address. Invoking the key's {@link |
| * MembershipKey#drop drop} method drops membership so that datagrams from the |
| * source address can no longer be received. |
| * |
| * <h2>Platform dependencies</h2> |
| * |
| * The multicast implementation is intended to map directly to the native |
| * multicasting facility. Consequently, the following items should be considered |
| * when developing an application that receives IP multicast datagrams: |
| * |
| * <ol> |
| * |
| * <li><p> The creation of the channel should specify the {@link ProtocolFamily} |
| * that corresponds to the address type of the multicast groups that the channel |
| * will join. There is no guarantee that a channel to a socket in one protocol |
| * family can join and receive multicast datagrams when the address of the |
| * multicast group corresponds to another protocol family. For example, it is |
| * implementation specific if a channel to an {@link StandardProtocolFamily#INET6 IPv6} |
| * socket can join an {@link StandardProtocolFamily#INET IPv4} multicast group and receive |
| * multicast datagrams sent to the group. </p></li> |
| * |
| * <li><p> The channel's socket should be bound to the {@link |
| * InetAddress#isAnyLocalAddress wildcard} address. If the socket is bound to |
| * a specific address, rather than the wildcard address then it is implementation |
| * specific if multicast datagrams are received by the socket. </p></li> |
| * |
| * <li><p> The {@link StandardSocketOptions#SO_REUSEADDR SO_REUSEADDR} option should be |
| * enabled prior to {@link NetworkChannel#bind binding} the socket. This is |
| * required to allow multiple members of the group to bind to the same |
| * address. </p></li> |
| * |
| * </ol> |
| * |
| * <p> <b>Usage Example:</b> |
| * <pre> |
| * // join multicast group on this interface, and also use this |
| * // interface for outgoing multicast datagrams |
| * NetworkInterface ni = NetworkInterface.getByName("hme0"); |
| * |
| * DatagramChannel dc = DatagramChannel.open(StandardProtocolFamily.INET) |
| * .setOption(StandardSocketOptions.SO_REUSEADDR, true) |
| * .bind(new InetSocketAddress(5000)) |
| * .setOption(StandardSocketOptions.IP_MULTICAST_IF, ni); |
| * |
| * InetAddress group = InetAddress.getByName("225.4.5.6"); |
| * |
| * MembershipKey key = dc.join(group, ni); |
| * </pre> |
| * |
| * @since 1.7 |
| */ |
| |
| public interface MulticastChannel |
| extends NetworkChannel |
| { |
| /** |
| * Closes this channel. |
| * |
| * <p> If the channel is a member of a multicast group then the membership |
| * is {@link MembershipKey#drop dropped}. Upon return, the {@link |
| * MembershipKey membership-key} will be {@link MembershipKey#isValid |
| * invalid}. |
| * |
| * <p> This method otherwise behaves exactly as specified by the {@link |
| * Channel} interface. |
| * |
| * @throws IOException |
| * If an I/O error occurs |
| */ |
| @Override void close() throws IOException; |
| |
| /** |
| * Joins a multicast group to begin receiving all datagrams sent to the group, |
| * returning a membership key. |
| * |
| * <p> If this channel is currently a member of the group on the given |
| * interface to receive all datagrams then the membership key, representing |
| * that membership, is returned. Otherwise this channel joins the group and |
| * the resulting new membership key is returned. The resulting membership key |
| * is not {@link MembershipKey#sourceAddress source-specific}. |
| * |
| * <p> A multicast channel may join several multicast groups, including |
| * the same group on more than one interface. An implementation may impose a |
| * limit on the number of groups that may be joined at the same time. |
| * |
| * @param group |
| * The multicast address to join |
| * @param interf |
| * The network interface on which to join the group |
| * |
| * @return The membership key |
| * |
| * @throws IllegalArgumentException |
| * If the group parameter is not a {@link InetAddress#isMulticastAddress |
| * multicast} address, or the group parameter is an address type |
| * that is not supported by this channel |
| * @throws IllegalStateException |
| * If the channel already has source-specific membership of the |
| * group on the interface |
| * @throws UnsupportedOperationException |
| * If the channel's socket is not an Internet Protocol socket |
| * @throws ClosedChannelException |
| * If this channel is closed |
| * @throws IOException |
| * If an I/O error occurs |
| * @throws SecurityException |
| * If a security manager is set, and its |
| * {@link SecurityManager#checkMulticast(InetAddress) checkMulticast} |
| * method denies access to the multiast group |
| */ |
| MembershipKey join(InetAddress group, NetworkInterface interf) |
| throws IOException; |
| |
| /** |
| * Joins a multicast group to begin receiving datagrams sent to the group |
| * from a given source address. |
| * |
| * <p> If this channel is currently a member of the group on the given |
| * interface to receive datagrams from the given source address then the |
| * membership key, representing that membership, is returned. Otherwise this |
| * channel joins the group and the resulting new membership key is returned. |
| * The resulting membership key is {@link MembershipKey#sourceAddress |
| * source-specific}. |
| * |
| * <p> Membership is <em>cumulative</em> and this method may be invoked |
| * again with the same group and interface to allow receiving datagrams sent |
| * by other source addresses to the group. |
| * |
| * @param group |
| * The multicast address to join |
| * @param interf |
| * The network interface on which to join the group |
| * @param source |
| * The source address |
| * |
| * @return The membership key |
| * |
| * @throws IllegalArgumentException |
| * If the group parameter is not a {@link |
| * InetAddress#isMulticastAddress multicast} address, the |
| * source parameter is not a unicast address, the group |
| * parameter is an address type that is not supported by this channel, |
| * or the source parameter is not the same address type as the group |
| * @throws IllegalStateException |
| * If the channel is currently a member of the group on the given |
| * interface to receive all datagrams |
| * @throws UnsupportedOperationException |
| * If the channel's socket is not an Internet Protocol socket or |
| * source filtering is not supported |
| * @throws ClosedChannelException |
| * If this channel is closed |
| * @throws IOException |
| * If an I/O error occurs |
| * @throws SecurityException |
| * If a security manager is set, and its |
| * {@link SecurityManager#checkMulticast(InetAddress) checkMulticast} |
| * method denies access to the multiast group |
| */ |
| MembershipKey join(InetAddress group, NetworkInterface interf, InetAddress source) |
| throws IOException; |
| } |
