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Since: API Level 1

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

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Inherited Constants

From interface java.net.SocketOptions

int	IP_MULTICAST_IF	This is an IPv4-only socket option whose functionality is subsumed by `IP_MULTICAST_IF` and not implemented on Android.
int	IP_MULTICAST_IF2	This integer option sets the outgoing interface for multicast packets using an interface index.
int	IP_MULTICAST_LOOP	This boolean option specifies whether the local loopback of multicast packets is enabled or disabled.
int	IP_TOS	This integer option specifies the value for the type-of-service field of the IPv4 header, or the traffic class field of the IPv6 header.
int	SO_BINDADDR	This option does not correspond to any Unix socket option and is not implemented on Android.
int	SO_BROADCAST	This boolean option can be used to enable broadcasting on datagram sockets.
int	SO_KEEPALIVE	This boolean option specifies whether the kernel sends keepalive messages.
int	SO_LINGER	Number of seconds to wait when closing a socket if there is still some buffered data to be sent.
int	SO_OOBINLINE	This boolean option specifies whether sending TCP urgent data is supported on this socket or not.
int	SO_RCVBUF	The size in bytes of a socket's receive buffer.
int	SO_REUSEADDR	This boolean option specifies whether a reuse of a local address is allowed even if another socket is not yet removed by the operating system.
int	SO_SNDBUF	The size in bytes of a socket's send buffer.
int	SO_TIMEOUT	Integer timeout in milliseconds for blocking accept or read/receive operations (but not write/send operations).
int	TCP_NODELAY	This boolean option specifies whether data is sent immediately on this socket.

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() Returns the local port to which this socket is bound.
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.

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Inherited Methods

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

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

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.

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.

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.

Results

Interfaces

Classes

Enums

Exceptions

DatagramSocketImpl

Class Overview

Summary

Fields

protected FileDescriptor fd

protected int localPort

Public Constructors

public DatagramSocketImpl ()

Protected Methods

protected abstract void bind (int port, InetAddress addr)

Parameters

Throws

protected abstract void close ()

protected void connect (InetAddress inetAddr, int port)

Parameters

Throws

protected abstract void create ()

Throws

protected void disconnect ()

protected FileDescriptor getFileDescriptor ()

Returns

protected int getLocalPort ()

protected abstract byte getTTL ()

Returns

Throws

See Also

protected abstract int getTimeToLive ()

Returns

Throws

protected abstract void join (InetAddress addr)

Parameters

Throws

protected abstract void joinGroup (SocketAddress addr, NetworkInterface netInterface)

Parameters

Throws

protected abstract void leave (InetAddress addr)

Parameters

Throws

protected abstract void leaveGroup (SocketAddress addr, NetworkInterface netInterface)

Parameters

Throws

protected abstract int peek (InetAddress sender)

Parameters

Returns

Throws

protected abstract int peekData (DatagramPacket pack)

Parameters

Returns

Throws

protected abstract void receive (DatagramPacket pack)

Parameters

Throws

protected abstract void send (DatagramPacket pack)

Parameters

Throws

protected abstract void setTTL (byte ttl)

Parameters

Throws

See Also

protected abstract void setTimeToLive (int ttl)

Parameters

Throws