--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/sample/nio/multicast/MulticastAddress.java	Sun Aug 31 18:39:01 2008 +0100
@@ -0,0 +1,127 @@
+/*
+ * Copyright 2007-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Sun Microsystems nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.net.UnknownHostException;
+import java.net.SocketException;
+
+/**
+ * Parses and represents a multicast address.
+ */
+
+class MulticastAddress {
+    private final InetAddress group;
+    private final int port;
+    private final NetworkInterface interf;
+
+    private MulticastAddress(InetAddress group, int port, NetworkInterface interf) {
+        this.group = group;
+        this.port = port;
+        this.interf = interf;
+    }
+
+    InetAddress group() {
+        return group;
+    }
+
+    int port() {
+        return port;
+    }
+
+    /**
+     * @return  The network interface, may be {@code null}
+     */
+    NetworkInterface interf() {
+        return interf;
+    }
+
+    /**
+     * Parses a string of the form "group:port[@interface]", returning
+     * a MulticastAddress representing the address
+     */
+    static MulticastAddress parse(String s) {
+        String[] components = s.split("@");
+        if (components.length > 2)
+            throw new IllegalArgumentException("At most one '@' expected");
+
+        // get group and port
+        String target = components[0];
+        int len = components[0].length();
+        int colon = components[0].lastIndexOf(':');
+        if ((colon < 1) || (colon > (len-2)))
+            throw new IllegalArgumentException("group:port expected");
+        String groupString = target.substring(0, colon);
+        int port = -1;
+        try {
+            port = Integer.parseInt(target.substring(colon+1, len));
+        } catch (NumberFormatException x) {
+             throw new IllegalArgumentException(x);
+        }
+
+        // handle IPv6 literal address
+        if (groupString.charAt(0) == '[') {
+            len = groupString.length();
+            if (groupString.charAt(len-1) != ']')
+                throw new IllegalArgumentException("missing ']'");
+            groupString = groupString.substring(1,len-1);
+            if (groupString.length() == 0)
+                throw new IllegalArgumentException("missing IPv6 address");
+        }
+
+        // get group address
+        InetAddress group = null;
+        try {
+            group = InetAddress.getByName(groupString);
+        } catch (UnknownHostException x) {
+            throw new IllegalArgumentException(x);
+        }
+        if (!group.isMulticastAddress()) {
+            throw new IllegalArgumentException("'" + group.getHostAddress() +
+                "' is not multicast address");
+        }
+
+        // optional interface
+        NetworkInterface interf = null;
+        if (components.length == 2) {
+            try {
+                interf = NetworkInterface.getByName(components[1]);
+            } catch (SocketException x) {
+                throw new IllegalArgumentException(x);
+            }
+            if (interf == null) {
+                throw new IllegalArgumentException("'" + components[1] +
+                   "' is not valid interface");
+            }
+        }
+        return new MulticastAddress(group, port, interf);
+    }
+}