| /* MulticastSocket.java -- Class for using multicast sockets |
| Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 |
| Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package java.net; |
| |
| import java.io.IOException; |
| import java.util.Enumeration; |
| |
| /** |
| * Written using on-line Java Platform 1.2 API Specification, as well |
| * as "The Java Class Libraries", 2nd edition (Addison-Wesley, 1998). |
| * Status: Believed complete and correct. |
| */ |
| |
| /** |
| * This class models a multicast UDP socket. A multicast address is a |
| * class D internet address (one whose most significant bits are 1110). |
| * A multicast group consists of a multicast address and a well known |
| * port number. All members of the group listening on that address and |
| * port will receive all the broadcasts to the group. |
| * <p> |
| * Please note that applets are not allowed to use multicast sockets |
| * |
| * Written using on-line Java Platform 1.2 API Specification, as well |
| * as "The Java Class Libraries", 2nd edition (Addison-Wesley, 1998). |
| * Status: Believed complete and correct. |
| * |
| * @author Warren Levy <warrenl@cygnus.com> |
| * @author Aaron M. Renn (arenn@urbanophile.com) (Documentation comments) |
| * @since 1.1 |
| * @date May 18, 1999. |
| */ |
| public class MulticastSocket extends DatagramSocket |
| { |
| // FIXME: the local addr bound to the multicast socket can be reused; |
| // unlike unicast sockets. It binds to any available network interface. |
| // See p.1159 JCL book. |
| |
| /** |
| * Create a MulticastSocket that this not bound to any address |
| * |
| * @exception IOException If an error occurs |
| * @exception SecurityException If a security manager exists and its |
| * checkListen method doesn't allow the operation |
| */ |
| public MulticastSocket() throws IOException |
| { |
| super(0, null); |
| } |
| |
| /** |
| * Create a multicast socket bound to the specified port |
| * |
| * @param port The port to bind to |
| * |
| * @exception IOException If an error occurs |
| * @exception SecurityException If a security manager exists and its |
| * checkListen method doesn't allow the operation |
| */ |
| public MulticastSocket(int port) throws IOException |
| { |
| super(port, null); |
| } |
| |
| /** |
| * Create a multicast socket bound to the specified SocketAddress. |
| * |
| * @param address The SocketAddress the multicast socket will be bound to |
| * |
| * @exception IOException If an error occurs |
| * @exception SecurityException If a security manager exists and its |
| * checkListen method doesn't allow the operation |
| * |
| * @since 1.4 |
| */ |
| public MulticastSocket(SocketAddress address) throws IOException |
| { |
| super(address); |
| } |
| |
| /** |
| * Returns the interface being used for multicast packets |
| * |
| * @return The multicast interface |
| * |
| * @exception SocketException If an error occurs |
| */ |
| public InetAddress getInterface() throws SocketException |
| { |
| return (InetAddress) impl.getOption(SocketOptions.IP_MULTICAST_IF); |
| } |
| |
| /** |
| * Returns the current value of the "Time to Live" option. This is the |
| * number of hops a packet can make before it "expires". This method id |
| * deprecated. Use <code>getTimeToLive</code> instead. |
| * |
| * @return The TTL value |
| * |
| * @exception IOException If an error occurs |
| * |
| * @deprecated 1.2 Replaced by getTimeToLive() |
| * |
| * @see Multicastsocket:getTimeToLive |
| */ |
| public byte getTTL() throws IOException |
| { |
| // Use getTTL here rather than getTimeToLive in case we're using an impl |
| // other than the default PlainDatagramSocketImpl and it doesn't have |
| // getTimeToLive yet. |
| return impl.getTTL(); |
| } |
| |
| /** |
| * Returns the current value of the "Time to Live" option. This is the |
| * number of hops a packet can make before it "expires". |
| * |
| * @return The TTL value |
| * |
| * @exception IOException If an error occurs |
| * |
| * @since 1.2 |
| */ |
| public int getTimeToLive() throws IOException |
| { |
| return impl.getTimeToLive(); |
| } |
| |
| /** |
| * Sets the interface to use for sending multicast packets. |
| * |
| * @param addr The new interface to use. |
| * |
| * @exception SocketException If an error occurs. |
| * |
| * @since 1.4 |
| */ |
| public void setInterface(InetAddress addr) throws SocketException |
| { |
| impl.setOption(SocketOptions.IP_MULTICAST_IF, addr); |
| } |
| |
| /** |
| * Sets the local network interface used to send multicast messages |
| * |
| * @param netIF The local network interface used to send multicast messages |
| * |
| * @exception SocketException If an error occurs |
| * |
| * @see MulticastSocket:getNetworkInterface |
| * |
| * @since 1.4 |
| */ |
| public void setNetworkInterface(NetworkInterface netIf) |
| throws SocketException |
| { |
| if (impl == null) |
| throw new SocketException ( |
| "MulticastSocket: Cant access socket implementation"); |
| |
| Enumeration e = netIf.getInetAddresses (); |
| |
| if (!e.hasMoreElements ()) |
| throw new SocketException ("MulticastSocket: Error"); |
| |
| InetAddress address = (InetAddress) e.nextElement (); |
| impl.setOption (SocketOptions.IP_MULTICAST_IF, address); |
| } |
| |
| /** |
| * Gets the local network interface which is used to send multicast messages |
| * |
| * @return The local network interface to send multicast messages |
| * |
| * @exception SocketException If an error occurs |
| * |
| * @see MulticastSocket:setNetworkInterface |
| * |
| * @since 1.4 |
| */ |
| public NetworkInterface getNetworkInterface() |
| throws SocketException |
| { |
| if (impl == null) |
| throw new SocketException ( |
| "MulticastSocket: Cant access socket implementation"); |
| |
| InetAddress address = |
| (InetAddress) impl.getOption (SocketOptions.IP_MULTICAST_IF); |
| NetworkInterface netIf = NetworkInterface.getByInetAddress (address); |
| |
| return netIf; |
| } |
| |
| /** |
| * Disable/Enable local loopback of multicast packets. 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. |
| * |
| * Because this option is a hint, applications that want to verify what |
| * loopback mode is set to should call #getLoopbackMode |
| * |
| * @param disable True to disable loopback mode |
| * |
| * @exception SocketException If an error occurs |
| * |
| * @since 1.4 |
| */ |
| public void setLoopbackMode(boolean disable) throws SocketException |
| { |
| if (impl == null) |
| throw new SocketException ( |
| "MulticastSocket: Cant access socket implementation"); |
| |
| impl.setOption (SocketOptions.IP_MULTICAST_LOOP, new Boolean (disable)); |
| } |
| |
| /** |
| * Checks if local loopback mode is enabled or not |
| * |
| * @exception SocketException If an error occurs |
| * |
| * @since 1.4 |
| */ |
| public boolean getLoopbackMode() throws SocketException |
| { |
| Object obj = impl.getOption (SocketOptions.IP_MULTICAST_LOOP); |
| |
| if (obj instanceof Boolean) |
| return ((Boolean) obj).booleanValue (); |
| else |
| throw new SocketException ("Unexpected type"); |
| } |
| |
| /** |
| * Sets the "Time to Live" value for a socket. The value must be between |
| * 1 and 255. |
| * |
| * @param ttl The new TTL value |
| * |
| * @exception IOException If an error occurs |
| * |
| * @deprecated 1.2 Replaced by <code>setTimeToLive</code> |
| * |
| * @see MulticastSocket:setTimeToLive |
| */ |
| public void setTTL(byte ttl) throws IOException |
| { |
| // Use setTTL here rather than setTimeToLive in case we're using an impl |
| // other than the default PlainDatagramSocketImpl and it doesn't have |
| // setTimeToLive yet. |
| impl.setTTL(ttl); |
| } |
| |
| /** |
| * Sets the "Time to Live" value for a socket. The value must be between |
| * 1 and 255. |
| * |
| * @param ttl The new TTL value |
| * |
| * @exception IOException If an error occurs |
| * |
| * @since 1.2 |
| */ |
| public void setTimeToLive(int ttl) throws IOException |
| { |
| if (ttl <= 0 || ttl > 255) |
| throw new IllegalArgumentException("Invalid ttl: " + ttl); |
| |
| impl.setTimeToLive(ttl); |
| } |
| |
| /** |
| * Joins the specified mulitcast group. |
| * |
| * @param addr The address of the group to join |
| * |
| * @exception IOException If an error occurs |
| * @exception SecurityException If a security manager exists and its |
| * checkMulticast method doesn't allow the operation |
| */ |
| public void joinGroup(InetAddress mcastaddr) throws IOException |
| { |
| if (! mcastaddr.isMulticastAddress()) |
| throw new IOException("Not a Multicast address"); |
| |
| SecurityManager s = System.getSecurityManager(); |
| if (s != null) |
| s.checkMulticast(mcastaddr); |
| |
| impl.join(mcastaddr); |
| } |
| |
| /** |
| * Leaves the specified multicast group |
| * |
| * @param addr The address of the group to leave |
| * |
| * @exception IOException If an error occurs |
| * @exception SecurityException If a security manager exists and its |
| * checkMulticast method doesn't allow the operation |
| */ |
| public void leaveGroup(InetAddress mcastaddr) throws IOException |
| { |
| if (! mcastaddr.isMulticastAddress()) |
| throw new IOException("Not a Multicast address"); |
| |
| SecurityManager s = System.getSecurityManager(); |
| if (s != null) |
| s.checkMulticast(mcastaddr); |
| |
| impl.leave(mcastaddr); |
| } |
| |
| /** |
| * Joins the specified mulitcast group on a specified interface. |
| * |
| * @param mcastaddr The multicast address to join |
| * @param netIf The local network interface to receive the multicast |
| * messages on or null to defer the interface set by #setInterface or |
| * #setNetworkInterface |
| * |
| * @exception IOException If an error occurs |
| * @exception IllegalArgumentException If address type is not supported |
| * @exception SecurityException If a security manager exists and its |
| * checkMulticast method doesn't allow the operation |
| * |
| * @see MulticastSocket:setInterface |
| * @see MulticastSocket:setNetworkInterface |
| * |
| * @since 1.4 |
| */ |
| public void joinGroup(SocketAddress mcastaddr, NetworkInterface netIf) |
| throws IOException |
| { |
| if (! (mcastaddr instanceof InetSocketAddress)) |
| throw new IllegalArgumentException ("SocketAddress type not supported"); |
| |
| InetSocketAddress tmp = (InetSocketAddress) mcastaddr; |
| |
| if (! tmp.getAddress ().isMulticastAddress ()) |
| throw new IOException ("Not a Multicast address"); |
| |
| SecurityManager s = System.getSecurityManager (); |
| if (s != null) |
| s.checkMulticast (tmp.getAddress ()); |
| |
| impl.joinGroup (mcastaddr, netIf); |
| } |
| |
| /** |
| * Leaves the specified mulitcast group on a specified interface. |
| * |
| * @param mcastaddr The multicast address to leave |
| * @param netIf The local networki interface or null to defer to the |
| * interface set by setInterface or setNetworkInterface |
| * |
| * @exception IOException If an error occurs |
| * @exception IllegalArgumentException If address type is not supported |
| * @exception SecurityException If a security manager exists and its |
| * checkMulticast method doesn't allow the operation |
| * |
| * @see MulticastSocket:setInterface |
| * @see MulticastSocket:setNetworkInterface |
| * |
| * @since 1.4 |
| */ |
| public void leaveGroup(SocketAddress mcastaddr, NetworkInterface netIf) |
| throws IOException |
| { |
| InetSocketAddress tmp = (InetSocketAddress) mcastaddr; |
| |
| if (! tmp.getAddress ().isMulticastAddress ()) |
| throw new IOException ("Not a Multicast address"); |
| |
| SecurityManager s = System.getSecurityManager (); |
| if (s != null) |
| s.checkMulticast (tmp.getAddress ()); |
| |
| impl.leaveGroup (mcastaddr, netIf); |
| } |
| |
| /** |
| * Sends a packet of data to a multicast address with a TTL that is |
| * different from the default TTL on this socket. The default TTL for |
| * the socket is not changed. |
| * |
| * @param packet The packet of data to send |
| * @param ttl The TTL for this packet |
| * |
| * @exception IOException If an error occurs |
| * @exception SecurityException If a security manager exists and its |
| * checkConnect or checkMulticast method doesn't allow the operation |
| */ |
| public synchronized void send(DatagramPacket p, byte ttl) throws IOException |
| { |
| SecurityManager s = System.getSecurityManager(); |
| if (s != null) |
| { |
| InetAddress addr = p.getAddress(); |
| if (addr.isMulticastAddress()) |
| s.checkMulticast(addr, ttl); |
| else |
| s.checkConnect(addr.getHostAddress(), p.getPort()); |
| } |
| |
| int oldttl = impl.getTimeToLive(); |
| impl.setTimeToLive(((int) ttl) & 0xFF); |
| impl.send(p); |
| impl.setTimeToLive(oldttl); |
| } |
| } // class MulticastSocket |