/**@class java.nio.channels.MulticastChannel implements java.nio.channels.NetworkChannel 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 java.nio.channels.MembershipKey#drop drop} method on the returned {@link java.nio.channels.MembershipKey}. If the underlying platform supports source filtering then the {@link java.nio.channels.MembershipKey#block block} and {@link java.nio.channels.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 java.nio.channels.MembershipKey} that represents membership to receive datagrams from the given source address. Invoking the key's {@link java.nio.channels.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 java.nio.channels.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 */ var MulticastChannel = { /**Closes this channel. <p> If the channel is a member of a multicast group then the membership is {@link java.nio.channels.MembershipKey#drop dropped}. Upon return, the {@link java.nio.channels.MembershipKey membership-key} will be {@link java.nio.channels.MembershipKey#isValid invalid}. <p> This method otherwise behaves exactly as specified by the {@link java.nio.channels.Channel} interface. @throws IOException If an I/O error occurs */ close : function( ) {}, /**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 java.nio.channels.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 {Object {InetAddress}} group The multicast address to join @param {Object {NetworkInterface}} interf The network interface on which to join the group @return {Object {java.nio.channels.MembershipKey}} 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 */ join : function( ) {}, /**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 java.nio.channels.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 {Object {InetAddress}} group The multicast address to join @param {Object {NetworkInterface}} interf The network interface on which to join the group @param {Object {InetAddress}} source The source address @return {Object {java.nio.channels.MembershipKey}} 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 */ join : function( ) {}, };