java.net.MulticastSocket Maven / Gradle / Ivy
/*
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Any work generated from this file, such as unified javadocs or compiled
stub files, must be accompanied by this notice in its entirety.
This work corresponds to the API signatures of JSR 219: Foundation
Profile 1.1. In the event of a discrepency between this work and the
JSR 219 specification, which is available at
http://www.jcp.org/en/jsr/detail?id=219, the latter takes precedence.
*/
package java.net;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.util.Enumeration;
/**
* The multicast datagram socket class is useful for sending
* and receiving IP multicast packets. A MulticastSocket is
* a (UDP) DatagramSocket, with additional capabilities for
* joining "groups" of other multicast hosts on the internet.
*
* A multicast group is specified by a class D IP address
* and by a standard UDP port number. Class D IP addresses
* are in the range 224.0.0.0 to 239.255.255.255,
* inclusive. The address 224.0.0.0 is reserved and should not be used.
*
* One would join a multicast group by first creating a MulticastSocket
* with the desired port, then invoking the
* joinGroup(InetAddress groupAddr)
* method:
*
* // join a Multicast group and send the group salutations
* ...
* String msg = "Hello";
* InetAddress group = InetAddress.getByName("228.5.6.7");
* MulticastSocket s = new MulticastSocket(6789);
* s.joinGroup(group);
* DatagramPacket hi = new DatagramPacket(msg.getBytes(), msg.length(),
* group, 6789);
* s.send(hi);
* // get their responses!
* byte[] buf = new byte[1000];
* DatagramPacket recv = new DatagramPacket(buf, buf.length);
* s.receive(recv);
* ...
* // OK, I'm done talking - leave the group...
* s.leaveGroup(group);
*
*
* When one sends a message to a multicast group, all subscribing
* recipients to that host and port receive the message (within the
* time-to-live range of the packet, see below). The socket needn't
* be a member of the multicast group to send messages to it.
*
* When a socket subscribes to a multicast group/port, it receives
* datagrams sent by other hosts to the group/port, as do all other
* members of the group and port. A socket relinquishes membership
* in a group by the leaveGroup(InetAddress addr) method.
* Multiple MulticastSocket's may subscribe to a multicast group
* and port concurrently, and they will all receive group datagrams.
*
* Currently applets are not allowed to use multicast sockets.
*
* @author Pavani Diwanji
* @since JDK1.1
*/
public class MulticastSocket extends DatagramSocket
{
/**
* Create a multicast socket.
*
*
If there is a security manager,
* its checkListen method is first called
* with 0 as its argument to ensure the operation is allowed.
* This could result in a SecurityException.
*
* When the socket is created the
* {@link DatagramSocket#setReuseAddress(true)} method is
* called to enable the SO_REUSEADDR socket option.
*
* @exception IOException if an I/O exception occurs
* while creating the MulticastSocket
* @exception SecurityException if a security manager exists and its
* checkListen method doesn't allow the operation.
* @see SecurityManager#checkListen
* @see java.net.DatagramSocket#setReuseAddress(boolean)
*/
public MulticastSocket() throws IOException { }
/**
* Create a multicast socket and bind it to a specific port.
*
*
If there is a security manager,
* its checkListen method is first called
* with the port argument
* as its argument to ensure the operation is allowed.
* This could result in a SecurityException.
*
* When the socket is created the
* {@link DatagramSocket#setReuseAddress(true)} method is
* called to enable the SO_REUSEADDR socket option.
*
* @param port port to use
* @exception IOException if an I/O exception occurs
* while creating the MulticastSocket
* @exception SecurityException if a security manager exists and its
* checkListen method doesn't allow the operation.
* @see SecurityManager#checkListen
* @see java.net.DatagramSocket#setReuseAddress(boolean)
*/
public MulticastSocket(int port) throws IOException { }
/**
* Create a MulticastSocket bound to the specified socket address.
*
* Or, if the address is null, create an unbound socket.
*
*
If there is a security manager,
* its checkListen method is first called
* with the SocketAddress port as its argument to ensure the operation is allowed.
* This could result in a SecurityException.
*
* When the socket is created the
* {@link DatagramSocket#setReuseAddress(true)} method is
* called to enable the SO_REUSEADDR socket option.
*
* @param bindaddr Socket address to bind to, or null for
* an unbound socket.
* @exception IOException if an I/O exception occurs
* while creating the MulticastSocket
* @exception SecurityException if a security manager exists and its
* checkListen method doesn't allow the operation.
* @see SecurityManager#checkListen
* @see java.net.DatagramSocket#setReuseAddress(boolean)
*
* @since 1.4
*/
public MulticastSocket(SocketAddress bindaddr) throws IOException { }
/**
* Set the default time-to-live for multicast packets sent out
* on this MulticastSocket in order to control the
* scope of the multicasts.
*
*
The ttl must be in the range 0 <= ttl <=
* 255 or an IllegalArgumentException will be thrown.
* @exception IOException if an I/O exception occurs
* while setting the default time-to-live value
* @param ttl the time-to-live
* @see #getTimeToLive()
*/
public void setTimeToLive(int ttl) throws IOException { }
/**
* Get the default time-to-live for multicast packets sent out on
* the socket.
* @exception IOException if an I/O exception occurs while
* getting the default time-to-live value
* @return the default time-to-live value
* @see #setTimeToLive(int)
*/
public int getTimeToLive() throws IOException {
return 0;
}
/**
* Joins a multicast group. Its behavior may be affected by
* setInterface or setNetworkInterface.
*
*
If there is a security manager, this method first
* calls its checkMulticast method
* with the mcastaddr argument
* as its argument.
*
* @param mcastaddr is the multicast address to join
*
* @exception IOException if there is an error joining
* or when the address is not a multicast address.
* @exception SecurityException if a security manager exists and its
* checkMulticast method doesn't allow the join.
*
* @see SecurityManager#checkMulticast(InetAddress)
*/
public void joinGroup(InetAddress mcastaddr) throws IOException { }
/**
* Leave a multicast group. Its behavior may be affected by
* setInterface or setNetworkInterface.
*
*
If there is a security manager, this method first
* calls its checkMulticast method
* with the mcastaddr argument
* as its argument.
*
* @param mcastaddr is the multicast address to leave
* @exception IOException if there is an error leaving
* or when the address is not a multicast address.
* @exception SecurityException if a security manager exists and its
* checkMulticast method doesn't allow the operation.
*
* @see SecurityManager#checkMulticast(InetAddress)
*/
public void leaveGroup(InetAddress mcastaddr) throws IOException { }
/**
* Joins the specified multicast group at the specified interface.
*
*
If there is a security manager, this method first
* calls its checkMulticast method
* with the mcastaddr argument
* as its argument.
*
* @param mcastaddr is the multicast address to join
* @param netIf specifies the local interface to receive multicast
* datagram packets, or null to defer to the interface set by
* {@link MulticastSocket#setInterface(InetAddress)} or
* {@link MulticastSocket#setNetworkInterface(NetworkInterface)}
*
* @exception IOException if there is an error joining
* or when the address is not a multicast address.
* @exception SecurityException if a security manager exists and its
* checkMulticast method doesn't allow the join.
* @throws IllegalArgumentException if mcastaddr is null or is a
* SocketAddress subclass not supported by this socket
*
* @see SecurityManager#checkMulticast(InetAddress)
* @since 1.4
*/
public void joinGroup(SocketAddress mcastaddr, NetworkInterface netIf)
throws IOException
{ }
/**
* Leave a multicast group on a specified local interface.
*
*
If there is a security manager, this method first
* calls its checkMulticast method
* with the mcastaddr argument
* as its argument.
*
* @param mcastaddr is the multicast address to leave
* @param netIf specifies the local interface or null to defer
* to the interface set by
* {@link MulticastSocket#setInterface(InetAddress)} or
* {@link MulticastSocket#setNetworkInterface(NetworkInterface)}
* @exception IOException if there is an error leaving
* or when the address is not a multicast address.
* @exception SecurityException if a security manager exists and its
* checkMulticast method doesn't allow the operation.
* @throws IllegalArgumentException if mcastaddr is null or is a
* SocketAddress subclass not supported by this socket
*
* @see SecurityManager#checkMulticast(InetAddress)
* @since 1.4
*/
public void leaveGroup(SocketAddress mcastaddr, NetworkInterface netIf)
throws IOException
{ }
/**
* Set the multicast network interface used by methods
* whose behavior would be affected by the value of the
* network interface. Useful for multihomed hosts.
* @param inf the InetAddress
* @exception SocketException if there is an error in
* the underlying protocol, such as a TCP error.
* @see #getInterface()
*/
public void setInterface(InetAddress inf) throws SocketException { }
/**
* Retrieve the address of the network interface used for
* multicast packets.
*
* @return An InetAddress representing
* the address of the network interface used for
* multicast packets.
*
* @exception SocketException if there is an error in
* the underlying protocol, such as a TCP error.
*
* @see #setInterface(java.net.InetAddress)
*/
public InetAddress getInterface() throws SocketException {
return null;
}
/**
* Specify the network interface for outgoing multicast datagrams
* sent on this socket.
*
* @param netIf the interface
* @exception SocketException if there is an error in
* the underlying protocol, such as a TCP error.
* @see #getNetworkInterface()
* @since 1.4
*/
public void setNetworkInterface(NetworkInterface netIf)
throws SocketException
{ }
/**
* Get the multicast network interface set.
*
* @exception SocketException if there is an error in
* the underlying protocol, such as a TCP error.
* @return the multicast NetworkInterface currently set
* @see #setNetworkInterface(NetworkInterface)
* @since 1.4
*/
public NetworkInterface getNetworkInterface() throws SocketException {
return null;
}
/**
* Disable/Enable local loopback of multicast datagrams
* 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
* {@link #getLoopbackMode()}
* @param disable true to disable the LoopbackMode
* @throws SocketException if an error occurs while setting the value
* @since 1.4
* @see #getLoopbackMode
*/
public void setLoopbackMode(boolean disable) throws SocketException { }
/**
* Get the setting for local loopback of multicast datagrams.
*
* @throws SocketException if an error occurs while getting the value
* @return true if the LoopbackMode has been disabled
* @since 1.4
* @see #setLoopbackMode
*/
public boolean getLoopbackMode() throws SocketException {
return false;
}
/**
* Sends a datagram packet to the destination, with a TTL (time-
* to-live) other than the default for the socket. This method
* need only be used in instances where a particular TTL is desired;
* otherwise it is preferable to set a TTL once on the socket, and
* use that default TTL for all packets. This method does not
* alter the default TTL for the socket. Its behavior may be
* affected by setInterface.
*
*
If there is a security manager, this method first performs some
* security checks. First, if p.getAddress().isMulticastAddress()
* is true, this method calls the
* security manager's checkMulticast method
* with p.getAddress() and ttl as its arguments.
* If the evaluation of that expression is false,
* this method instead calls the security manager's
* checkConnect method with arguments
* p.getAddress().getHostAddress() and
* p.getPort(). Each call to a security manager method
* could result in a SecurityException if the operation is not allowed.
*
* @param p is the packet to be sent. The packet should contain
* the destination multicast ip address and the data to be sent.
* One does not need to be the member of the group to send
* packets to a destination multicast address.
* @param ttl optional time to live for multicast packet.
* default ttl is 1.
*
* @exception IOException is raised if an error occurs i.e
* error while setting ttl.
* @exception SecurityException if a security manager exists and its
* checkMulticast or checkConnect
* method doesn't allow the send.
*
* @deprecated Use the following code or its equivalent instead:
* ......
* int ttl = mcastSocket.getTimeToLive();
* mcastSocket.setTimeToLive(newttl);
* mcastSocket.send(p);
* mcastSocket.setTimeToLive(ttl);
* ......
*
* @see DatagramSocket#send
* @see DatagramSocket#receive
* @see SecurityManager#checkMulticast(java.net.InetAddress, byte)
* @see SecurityManager#checkConnect
*/
public void send(DatagramPacket p, byte ttl) throws IOException { }
}