--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/nio/channels/MembershipKey.java Sun Aug 31 18:39:01 2008 +0100
@@ -0,0 +1,183 @@
+/*
+ * Copyright 2007-2008 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.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.util.List;
+
+/**
+ * A token representing the membership of an Internet Protocol (IP) multicast
+ * group.
+ *
+ * <p> A membership key may represent a membership to receive all datagrams sent
+ * to the group, or it may be <em>source-specific</em>, meaning that it
+ * represents a membership that receives only datagrams from a specific source
+ * address. Whether or not a membership key is source-specific may be determined
+ * by invoking its {@link #getSourceAddress() getSourceAddress} method.
+ *
+ * <p> A membership key is valid upon creation and remains valid until the
+ * membership is dropped by invoking the {@link #drop() drop} method, or
+ * the channel is closed. The validity of the membership key may be tested
+ * by invoking its {@link #isValid() isValid} method.
+ *
+ * <p> Where a membership key is not source-specific and the underlying operation
+ * system supports source filtering, then the {@link #block block} and {@link
+ * #unblock unblock} methods can be used to block or unblock multicast datagrams
+ * from particular source addresses.
+ *
+ * @see MulticastChannel
+ *
+ * @since 1.7
+ */
+public abstract class MembershipKey {
+
+ /**
+ * Initializes a new instance of this class.
+ */
+ protected MembershipKey() {
+ }
+
+ /**
+ * Tells whether or not this membership is valid.
+ *
+ * <p> A multicast group membership is valid upon creation and remains
+ * valid until the membership is dropped by invoking the {@link #drop() drop}
+ * method, or the channel is closed.
+ *
+ * @return {@code true} if this membership key is valid, {@code false}
+ * otherwise
+ */
+ public abstract boolean isValid();
+
+ /**
+ * Drop membership.
+ *
+ * <p> If the membership key represents a membership to receive all datagrams
+ * then the membership is dropped and the channel will no longer receive any
+ * datagrams sent to the group. If the membership key is source-specific
+ * then the channel will no longer receive datagrams sent to the group from
+ * that source address.
+ *
+ * <p> After membership is dropped it may still be possible to receive
+ * datagrams sent to the group. This can arise when datagrams are waiting to
+ * be received in the socket's receive buffer. After membership is dropped
+ * then the channel may {@link MulticastChannel#join join} the group again
+ * in which case a new membership key is returned.
+ *
+ * <p> Upon return, this membership object will be {@link #isValid() invalid}.
+ * If the multicast group membership is already invalid then invoking this
+ * method has no effect. Once a multicast group membership is invalid,
+ * it remains invalid forever.
+ *
+ * @throws IOException
+ * If an I/O error occurs
+ */
+ public abstract void drop() throws IOException;
+
+ /**
+ * Block multicast datagrams from the given source address.
+ *
+ * <p> If this membership key is not source-specific, and the underlying
+ * operating system supports source filtering, then this method blocks
+ * multicast datagrams from the given source address. If the given source
+ * address is already blocked then this method has no effect.
+ * After a source address is blocked it may still be possible to receive
+ * datagams from that source. This can arise when datagrams are waiting to
+ * be received in the socket's receive buffer.
+ *
+ * @param source
+ * The source address to block
+ *
+ * @return This membership key
+ *
+ * @throws IllegalArgumentException
+ * If the {@code source} parameter is not a unicast address or
+ * is not the same address type as the multicast group
+ * @throws IllegalStateException
+ * If this membership key is source-specific or is no longer valid
+ * @throws UnsupportedOperationException
+ * If the underlying operating system does not support source
+ * filtering
+ * @throws IOException
+ * If an I/O error occurs
+ */
+ public abstract MembershipKey block(InetAddress source) throws IOException;
+
+ /**
+ * Unblock multicast datagrams from the given source address that was
+ * previously blocked using the {@link #block(InetAddress) block} method.
+ *
+ * @param source
+ * The source address to unblock
+ *
+ * @return This membership key
+ *
+ * @throws IllegalStateException
+ * If the given source address is not currently blocked or the
+ * membership key is no longer valid
+ * @throws IOException
+ * If an I/O error occurs
+ */
+ public abstract MembershipKey unblock(InetAddress source) throws IOException;
+
+ /**
+ * Returns the channel for which this membership key was created. This
+ * method will continue to return the channel even after the membership
+ * becomes {@link #isValid invalid}.
+ *
+ * @return the channel
+ */
+ public abstract MulticastChannel getChannel();
+
+ /**
+ * Returns the multicast group for which this membership key was created.
+ * This method will continue to return the group even after the membership
+ * becomes {@link #isValid invalid}.
+ *
+ * @return the multicast group
+ */
+ public abstract InetAddress getGroup();
+
+ /**
+ * Returns the network interface for which this membership key was created.
+ * This method will continue to return the network interface even after the
+ * membership becomes {@link #isValid invalid}.
+ *
+ * @return the network interface
+ */
+ public abstract NetworkInterface getNetworkInterface();
+
+ /**
+ * Returns the source address if this membership key is source-specific,
+ * or {@code null} if this membership is not source-specific.
+ *
+ * @return The source address if this membership key is source-specific,
+ * otherwise {@code null}
+ */
+ public abstract InetAddress getSourceAddress();
+}