public abstract class

DatagramSocketImpl

extends Object
implements SocketOptions
java.lang.Object
   ↳ java.net.DatagramSocketImpl

Class Overview

The abstract superclass for datagram and multicast socket implementations.

Summary

[Expand]
Inherited Constants
From interface java.net.SocketOptions
Fields
protected FileDescriptor fd File descriptor that is used to address this socket.
protected int localPort The number of the local port to which this socket is bound.
Public Constructors
DatagramSocketImpl()
Constructs an unbound datagram socket implementation.
Protected Methods
abstract void bind(int port, InetAddress addr)
Binds the datagram socket to the given localhost/port.
abstract void close()
Closes this socket.
void connect(InetAddress inetAddr, int port)
Connects this socket to the specified remote address and port.
abstract void create()
This method allocates the socket descriptor in the underlying operating system.
void disconnect()
Disconnects this socket from the remote host.
FileDescriptor getFileDescriptor()
Gets the FileDescriptor of this datagram socket, which is invalid if the socket is closed or not bound.
int getLocalPort()
Gets the local port of this socket.
abstract byte getTTL()
This method is deprecated. Replaced by getTimeToLive()
abstract int getTimeToLive()
Gets the time-to-live (TTL) for multicast packets sent on this socket.
abstract void join(InetAddress addr)
Adds this socket to the multicast group addr.
abstract void joinGroup(SocketAddress addr, NetworkInterface netInterface)
Adds this socket to the multicast group addr.
abstract void leave(InetAddress addr)
Removes this socket from the multicast group addr.
abstract void leaveGroup(SocketAddress addr, NetworkInterface netInterface)
Removes this socket from the multicast group addr.
abstract int peek(InetAddress sender)
Peeks at the incoming packet to this socket and returns the address of the sender.
abstract int peekData(DatagramPacket pack)
Receives data into the supplied datagram packet by peeking.
abstract void receive(DatagramPacket pack)
Receives data and stores it in the supplied datagram packet pack.
abstract void send(DatagramPacket pack)
Sends the given datagram packet pack.
abstract void setTTL(byte ttl)
This method is deprecated. Replaced by setTimeToLive(int)
abstract void setTimeToLive(int ttl)
Sets the time-to-live (TTL) option for multicast packets sent on this socket.
[Expand]
Inherited Methods
From class java.lang.Object
From interface java.net.SocketOptions

Fields

protected FileDescriptor fd

Since: API Level 1

File descriptor that is used to address this socket.

protected int localPort

Since: API Level 1

The number of the local port to which this socket is bound.

Public Constructors

public DatagramSocketImpl ()

Since: API Level 1

Constructs an unbound datagram socket implementation.

Protected Methods

protected abstract void bind (int port, InetAddress addr)

Since: API Level 1

Binds the datagram socket to the given localhost/port. Sockets must be bound prior to attempting to send or receive data.

Parameters
port the port on the localhost to bind.
addr the address on the multihomed localhost to bind.
Throws
SocketException if an error occurs while binding, for example, if the port has been already bound.

protected abstract void close ()

Since: API Level 1

Closes this socket.

protected void connect (InetAddress inetAddr, int port)

Since: API Level 1

Connects this socket to the specified remote address and port.

Parameters
inetAddr the address of the target host which has to be connected.
port the port on the target host which has to be connected.
Throws
SocketException if the datagram socket cannot be connected to the specified remote address and port.

protected abstract void create ()

Since: API Level 1

This method allocates the socket descriptor in the underlying operating system.

Throws
SocketException if an error occurs while creating the socket.

protected void disconnect ()

Since: API Level 1

Disconnects this socket from the remote host.

protected FileDescriptor getFileDescriptor ()

Since: API Level 1

Gets the FileDescriptor of this datagram socket, which is invalid if the socket is closed or not bound.

Returns
  • the current file descriptor of this socket.

protected int getLocalPort ()

Since: API Level 1

Gets the local port of this socket.

Returns
  • the local port to which this socket is bound.

protected abstract byte getTTL ()

Since: API Level 1

This method is deprecated.
Replaced by getTimeToLive()

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

Returns
  • the time-to-live option as a byte value.
Throws
IOException if an error occurs while getting the time-to-live option value.
See Also

protected abstract int getTimeToLive ()

Since: API Level 1

Gets the time-to-live (TTL) for multicast packets sent on this socket. The TTL option defines how many routers a packet may be pass before it is discarded.

Returns
  • the time-to-live option as an integer value.
Throws
IOException if an error occurs while getting the time-to-live option value.

protected abstract void join (InetAddress addr)

Since: API Level 1

Adds this socket to the multicast group addr. A socket must join a group before being able to receive data. Further, a socket may be a member of multiple groups but may join any group only once.

Parameters
addr the multicast group to which this socket has to be joined.
Throws
IOException if an error occurs while joining the specified multicast group.

protected abstract void joinGroup (SocketAddress addr, NetworkInterface netInterface)

Since: API Level 1

Adds this socket to the multicast group addr. A socket must join a group before being able to receive data. Further, a socket may be a member of multiple groups but may join any group only once.

Parameters
addr the multicast group to which this socket has to be joined.
netInterface the local network interface which will receive the multicast datagram packets.
Throws
IOException if an error occurs while joining the specified multicast group.

protected abstract void leave (InetAddress addr)

Since: API Level 1

Removes this socket from the multicast group addr.

Parameters
addr the multicast group to be left.
Throws
IOException if an error occurs while leaving the group or no multicast address was assigned.

protected abstract void leaveGroup (SocketAddress addr, NetworkInterface netInterface)

Since: API Level 1

Removes this socket from the multicast group addr.

Parameters
addr the multicast group to be left.
netInterface the local network interface on which this socket has to be removed.
Throws
IOException if an error occurs while leaving the group.

protected abstract int peek (InetAddress sender)

Since: API Level 1

Peeks at the incoming packet to this socket and returns the address of the sender. The method will block until a packet is received or timeout expires.

Parameters
sender the origin address of a packet.
Returns
  • the address of sender as an integer value.
Throws
IOException if an error or a timeout occurs while reading the address.

protected abstract int peekData (DatagramPacket pack)

Since: API Level 1

Receives data into the supplied datagram packet by peeking. The data is not removed from socket buffer and can be received again by another peekData() or receive() call. This call blocks until either data has been received or, if a timeout is set, the timeout has been expired.

Parameters
pack the datagram packet used to store the data.
Returns
  • the port the packet was received from.
Throws
IOException if an error occurs while peeking at the data.

protected abstract void receive (DatagramPacket pack)

Since: API Level 1

Receives data and stores it in the supplied datagram packet pack. This call will block until either data has been received or, if a timeout is set, the timeout has expired. If the timeout expires an InterruptedIOException is thrown.

Parameters
pack the datagram packet container to fill in the received data.
Throws
IOException if an error or timeout occurs while receiving data.

protected abstract void send (DatagramPacket pack)

Since: API Level 1

Sends the given datagram packet pack. The packet contains the data and the address and port information of the target host as well.

Parameters
pack the datagram packet to be sent.
Throws
IOException if an error occurs while sending the packet.

protected abstract void setTTL (byte ttl)

Since: API Level 1

This method is deprecated.
Replaced by setTimeToLive(int)

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

Parameters
ttl the time-to-live option value. Valid values are 0 < ttl <= 255.
Throws
IOException if an error occurs while setting the option.
See Also

protected abstract void setTimeToLive (int ttl)

Since: API Level 1

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

Parameters
ttl the time-to-live option value. Valid values are 0 < ttl <= 255.
Throws
IOException if an error occurs while setting the option.