java.net

Class DatagramSocketImpl

Implemented Interfaces:
SocketOptions
Known Direct Subclasses:
PlainDatagramSocketImpl

public abstract class DatagramSocketImpl
extends Object
implements SocketOptions

This abstract class models a datagram socket implementation. An actual implementation class would implement these methods, probably via redirecting them to native code.

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.

Since:
1.1

Field Summary

protected FileDescriptor
fd
The FileDescriptor object for this object.
protected int
localPort
The local port to which this socket is bound

Fields inherited from interface java.net.SocketOptions

IP_MULTICAST_IF, IP_MULTICAST_IF2, IP_MULTICAST_LOOP, IP_TOS, SO_BINDADDR, SO_BROADCAST, SO_KEEPALIVE, SO_LINGER, SO_OOBINLINE, SO_RCVBUF, SO_REUSEADDR, SO_SNDBUF, SO_TIMEOUT, TCP_NODELAY

Constructor Summary

DatagramSocketImpl()
Default, no-argument constructor for subclasses to call.

Method Summary

protected abstract void
bind(int lport, InetAddress laddr)
This method binds the socket to the specified local port and address.
protected abstract void
close()
This methods closes the socket
protected void
connect(InetAddress address, int port)
Connects the socket to a host specified by address and port.
protected abstract void
create()
Creates a new datagram socket.
protected void
disconnect()
Disconnects the socket.
protected FileDescriptor
getFileDescriptor()
Returns the FileDescriptor for this socket
protected int
getLocalPort()
Returns the local port this socket is bound to
protected abstract byte
getTTL()
Deprecated. // FIXME: when ?
protected abstract int
getTimeToLive()
This method returns the current Time to Live (TTL) setting on this socket.
protected abstract void
join(InetAddress inetaddr)
Causes this socket to join the specified multicast group
protected abstract void
joinGroup(SocketAddress mcastaddr, NetworkInterface netIf)
Causes this socket to join the specified multicast group on a specified device
protected abstract void
leave(InetAddress inetaddr)
Causes the socket to leave the specified multicast group.
protected abstract void
leaveGroup(SocketAddress mcastaddr, NetworkInterface netIf)
Leaves a multicast group
protected abstract int
peek(InetAddress i)
Takes a peek at the next packet received in order to retrieve the address of the sender
protected abstract int
peekData(DatagramPacket p)
Takes a peek at the next packet received.
protected abstract void
receive(DatagramPacket p)
Receives a packet of data from the network Will block until a packet arrives.
protected abstract void
send(DatagramPacket p)
Transmits the specified packet of data to the network.
protected abstract void
setTTL(byte ttl)
Deprecated.
protected abstract void
setTimeToLive(int ttl)
Sets the Time to Live (TTL) setting on this socket to the specified value.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

fd

protected FileDescriptor fd
The FileDescriptor object for this object.

localPort

protected int localPort
The local port to which this socket is bound

Constructor Details

DatagramSocketImpl

public DatagramSocketImpl()
Default, no-argument constructor for subclasses to call.

Method Details

bind

protected abstract void bind(int lport,
                             InetAddress laddr)
            throws SocketException
This method binds the socket to the specified local port and address.
Parameters:
lport - The port number to bind to
laddr - The address to bind to
Throws:
SocketException - If an error occurs

close

protected abstract void close()
This methods closes the socket

connect

protected void connect(InetAddress address,
                       int port)
            throws SocketException
Connects the socket to a host specified by address and port.
Parameters:
address - The InetAddress of the host to connect to
port - The port number of the host to connect to
Throws:
SocketException - If an error occurs
Since:
1.4

create

protected abstract void create()
            throws SocketException
Creates a new datagram socket.
Throws:
SocketException - If an error occurs

disconnect

protected void disconnect()
Disconnects the socket.
Since:
1.4

getFileDescriptor

protected FileDescriptor getFileDescriptor()
Returns the FileDescriptor for this socket
Returns:
the file descriptor associated with this socket

getLocalPort

protected int getLocalPort()
Returns the local port this socket is bound to
Returns:
the local port

getTTL

protected abstract byte getTTL()
            throws IOException

Deprecated. // FIXME: when ?

This method returns the current Time to Live (TTL) setting on this socket. Use getTimeToLive() instead.
Returns:
the current time-to-live
Throws:
IOException - If an error occurs

getTimeToLive

protected abstract int getTimeToLive()
            throws IOException
This method returns the current Time to Live (TTL) setting on this socket.
Returns:
the current time-to-live
Throws:
IOException - If an error occurs

join

protected abstract void join(InetAddress inetaddr)
            throws IOException
Causes this socket to join the specified multicast group
Parameters:
inetaddr - The multicast address to join with
Throws:
IOException - If an error occurs

joinGroup

protected abstract void joinGroup(SocketAddress mcastaddr,
                                  NetworkInterface netIf)
            throws IOException
Causes this socket to join the specified multicast group on a specified device
Parameters:
mcastaddr - The address to leave
netIf - The specified network interface to join the group at
Throws:
IOException - If an error occurs
Since:
1.4

leave

protected abstract void leave(InetAddress inetaddr)
            throws IOException
Causes the socket to leave the specified multicast group.
Parameters:
inetaddr - The multicast address to leave
Throws:
IOException - If an error occurs

leaveGroup

protected abstract void leaveGroup(SocketAddress mcastaddr,
                                   NetworkInterface netIf)
            throws IOException
Leaves a multicast group
Parameters:
mcastaddr - The address to join
netIf - The specified network interface to leave the group at
Throws:
IOException - If an error occurs
Since:
1.4

peek

protected abstract int peek(InetAddress i)
            throws IOException
Takes a peek at the next packet received in order to retrieve the address of the sender
Parameters:
i - The InetAddress to fill in with the information about the sender if the next packet
Returns:
The port number of the sender of the packet
Throws:
IOException - If an error occurs

peekData

protected abstract int peekData(DatagramPacket p)
            throws IOException
Takes a peek at the next packet received. This packet is not consumed. With the next peekData/receive operation this packet will be read again.
Parameters:
p - The DatagramPacket to fill in with the data sent.
Returns:
The port number of the sender of the packet.
Throws:
IOException - If an error occurs
Since:
1.4

receive

protected abstract void receive(DatagramPacket p)
            throws IOException
Receives a packet of data from the network Will block until a packet arrives. The packet info in populated into the passed in DatagramPacket object.
Parameters:
p - A place to store the incoming packet.
Throws:
IOException - If an error occurs

send

protected abstract void send(DatagramPacket p)
            throws IOException
Transmits the specified packet of data to the network. The destination host and port should be encoded in the packet.
Parameters:
p - The packet to send
Throws:
IOException - If an error occurs

setTTL

protected abstract void setTTL(byte ttl)
            throws IOException

Deprecated.

Sets the Time to Live (TTL) setting on this socket to the specified value. Use setTimeToLive(int) instead.
Parameters:
ttl - The new Time to Live value
Throws:
IOException - If an error occurs

setTimeToLive

protected abstract void setTimeToLive(int ttl)
            throws IOException
Sets the Time to Live (TTL) setting on this socket to the specified value.
Parameters:
ttl - The new Time to Live value
Throws:
IOException - If an error occurs

DatagramSocketImpl.java -- Abstract class for UDP socket implementations 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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.