java.net
Class MulticastSocket

java.lang.Object
  java.net.DatagramSocket
      java.net.MulticastSocket

public class MulticastSocket
extends DatagramSocket

This class models a multicast socket for sending & receiving datagram packets to a multicast group.

See Also:

DatagramSocket

Field Summary

(package private) static int

SO_REUSEPORT

Fields inherited from class java.net.DatagramSocket

address, factory, impl, isBound, port

Constructor Summary

MulticastSocket()
Constructs a multicast socket, bound to any available port on the localhost.

MulticastSocket(int aPort)
Returns a multicast socket, bound to the nominated port on the localhost.

MulticastSocket(SocketAddress localAddr)
Constructs a MulticastSocket bound to the host/port specified by the SocketAddress, or an unbound DatagramSocket if the SocketAddress is null.

Method Summary

(package private) void	createSocket(int aPort, InetAddress addr)
InetAddress	getInterface() Answer the network address used by the socket.
boolean	getLoopbackMode() Get the state of the IP_MULTICAST_LOOP socket option.
NetworkInterface	getNetworkInterface() Answer the network interface used by the socket.
int	getTimeToLive() Answer the time-to-live (TTL) for multicast packets sent on this socket.
byte	getTTL() Deprecated. Replaced by getTimeToLive()
(package private) boolean	isMulticastSocket() Returns whether this socket is multicast.
void	joinGroup(InetAddress groupAddr) Add this socket to the multicast group.
void	joinGroup(SocketAddress groupAddress, NetworkInterface netInterface) Add this socket to the multicast group.
void	leaveGroup(InetAddress groupAddr) Remove the socket from the multicast group.
void	leaveGroup(SocketAddress groupAddress, NetworkInterface netInterface) Remove the socket from the multicast group.
void	send(DatagramPacket pack, byte ttl) Deprecated. use setTimeToLive(int)
void	setInterface(InetAddress addr) Set the network address used by the socket.
void	setLoopbackMode(boolean loop) Set the IP_MULTICAST_LOOP socket option.
void	setNetworkInterface(NetworkInterface netInterface) Set the network interface used by the socket.
void	setTimeToLive(int ttl) Set the time-to-live (TTL) for multicast packets sent on this socket.
void	setTTL(byte ttl) Deprecated. Replaced by setTimeToLive(int)

Methods inherited from class java.net.DatagramSocket

bind, checkClosedAndBind, checkListen, close, connect, connect, disconnect, getBroadcast, getChannel, getInetAddress, getLocalAddress, getLocalPort, getLocalSocketAddress, getPort, getReceiveBufferSize, getRemoteSocketAddress, getReuseAddress, getSendBufferSize, getSoTimeout, getTrafficClass, isBound, isClosed, isConnected, receive, send, setBroadcast, setDatagramSocketImplFactory, setReceiveBufferSize, setReuseAddress, setSendBufferSize, setSoTimeout, setTrafficClass

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SO_REUSEPORT

static final int SO_REUSEPORT

See Also:

Constant Field Values

Constructor Detail

MulticastSocket

public MulticastSocket()
                throws IOException

Constructs a multicast socket, bound to any available port on the localhost.

Throws:

IOException - if a problem occurs creating or binding the socket

MulticastSocket

public MulticastSocket(int aPort)
                throws IOException

Returns a multicast socket, bound to the nominated port on the localhost.

Parameters:

aPort - the port to bind on the localhost

Throws:

IOException - if a problem occurs creating or binding the socket

MulticastSocket

public MulticastSocket(SocketAddress localAddr)
                throws IOException

Constructs a MulticastSocket bound to the host/port specified by the SocketAddress, or an unbound DatagramSocket if the SocketAddress is null.

Parameters:

localAddr - the local machine address and port to bind to

Throws:

IllegalArgumentException - if the SocketAddress is not supported

IOException - if a problem occurs creating or binding the socket

Since:

1.4

Method Detail

getInterface

public InetAddress getInterface()
                         throws SocketException

Answer the network address used by the socket. This is useful on multi-homed machines.

Returns:

java.net.InetAddress the network address

Throws:

SocketException - The exception thrown while getting the address

getNetworkInterface

public NetworkInterface getNetworkInterface()
                                     throws SocketException

Answer the network interface used by the socket. This is useful on multi-homed machines.

Returns:

java.net.NetworkInterface the network address

Throws:

SocketException - The exception thrown while getting the address

Since:

1.4

getTimeToLive

public int getTimeToLive()
                  throws IOException

Answer the time-to-live (TTL) for multicast packets sent on this socket.

Returns:

java.net.InetAddress

Throws:

IOException - The exception description.

getTTL

@Deprecated
public byte getTTL()
            throws IOException

Deprecated. Replaced by getTimeToLive()

Answer the time-to-live (TTL) for multicast packets sent on this socket.

Returns:

java.net.InetAddress

Throws:

IOException - The exception description.

See Also:

getTimeToLive()

isMulticastSocket

boolean isMulticastSocket()

Description copied from class: DatagramSocket

Returns whether this socket is multicast.

Overrides:

isMulticastSocket in class DatagramSocket

Returns:

Always returns false.

joinGroup

public void joinGroup(InetAddress groupAddr)
               throws IOException

Add this socket to the multicast group. A socket must joint a group before data may be received. A socket may be a member of multiple groups but may join any group once.

Parameters:

groupAddr - the multicast group to be joined

Throws:

IOException - may be thrown while joining a group

joinGroup

public void joinGroup(SocketAddress groupAddress,
                      NetworkInterface netInterface)
               throws IOException

Add this socket to the multicast group. A socket must join a group before data may be received. A socket may be a member of multiple groups but may join any group once.

Parameters:

groupAddress - the multicast group to be joined

netInterface - the network interface on which the addresses should be dropped

Throws:

IOException - will be thrown if address is not a multicast address

SecurityException - will be thrown if caller is not authorized to join group

IllegalArgumentException - will be through if groupAddr is null

Since:

1.4

leaveGroup

public void leaveGroup(InetAddress groupAddr)
                throws IOException

Remove the socket from the multicast group.

Parameters:

groupAddr - the multicast group to be left

Throws:

IOException - will be thrown if address is not a multicast address

SecurityException - will be thrown if caller is not authorized to join group

IllegalArgumentException - will be through if groupAddr is null

leaveGroup

public void leaveGroup(SocketAddress groupAddress,
                       NetworkInterface netInterface)
                throws IOException

Remove the socket from the multicast group.

Parameters:

groupAddress - the multicast group to be left

netInterface - the network interface on which the addresses should be dropped

Throws:

IOException - will be thrown if address is not a multicast address

SecurityException - will be thrown if caller is not authorized to join group

IllegalArgumentException - will be through if groupAddr is null

Since:

1.4

send

@Deprecated
public void send(DatagramPacket pack,
                            byte ttl)
          throws IOException

Deprecated. use setTimeToLive(int)

Send the packet on this socket. The packet must satisfy the security policy before it may be sent.

Parameters:

pack - the DatagramPacket to send

ttl - the TTL setting for this transmission, overriding the socket default

Throws:

IOException - If a send error occurs.

setInterface

public void setInterface(InetAddress addr)
                  throws SocketException

Set the network address used by the socket. This is useful on multi-homed machines.

Parameters:

addr - java.net.InetAddress the interface network address

Throws:

SocketException - the exception may be thrown while setting the address

setNetworkInterface

public void setNetworkInterface(NetworkInterface netInterface)
                         throws SocketException

Set the network interface used by the socket. This is useful on multi-homed machines.

Parameters:

netInterface - NetworkInterface the interface to be used

Throws:

SocketException - the exception may be thrown while setting the address

Since:

1.4

setTimeToLive

public void setTimeToLive(int ttl)
                   throws IOException

Set the time-to-live (TTL) for multicast packets sent on this socket.

Parameters:

ttl - the time-to-live, 0<=ttl<= 255

Throws:

IOException - The exception thrown while setting the TTL

setTTL

@Deprecated
public void setTTL(byte ttl)
            throws IOException

Deprecated. Replaced by setTimeToLive(int)

Set the time-to-live (TTL) for multicast packets sent on this socket.

Parameters:

ttl - the time-to-live, 0Throws:

IOException - The exception thrown while setting the TTL

See Also:

setTimeToLive(int)

createSocket

void createSocket(int aPort,
                  InetAddress addr)
            throws SocketException

Overrides:

createSocket in class DatagramSocket

Throws:

SocketException

getLoopbackMode

public boolean getLoopbackMode()
                        throws SocketException

Get the state of the IP_MULTICAST_LOOP socket option.

Returns:

true if the IP_MULTICAST_LOOP is enabled, false otherwise.

Throws:

SocketException - if the socket is closed or the option is invalid.

Since:

1.4

setLoopbackMode

public void setLoopbackMode(boolean loop)
                     throws SocketException

Set the IP_MULTICAST_LOOP socket option.

Parameters:

loop - the socket IP_MULTICAST_LOOP option setting

Throws:

SocketException - if the socket is closed or the option is invalid.

Since:

1.4