A SocketChannel is a selectable channel for part abstraction of stream
connecting socket. The socket
method of this class can return
the related Socket
instance, which can handle the socket.
A socket channel is open but not connected when created by open
method. After connected by calling the connect
method, it will
keep connected before closed. The connection is non-blocking that the
connect
method is for the initial connection and following
finishConnect
method is for the final steps of connection. The
isConnectionPending
method can tell the connection is blocked
or not; the isConnected
method can tell the socket is
connected finally or not.
The shut down operation can be independent and asynchronous for input and
output. The shutdownInput
method is for input, and can make
the following read operation fail as end of stream. If the input is shut down
and another thread is pending in read operation, the read will end without
effect and return end of stream. The shutdownOutput
method is
for output, and can make the following write operation throwing a
ClosedChannelException
. If the output is shut down and
another is pending in a write operation, an
AsynchronousCloseException
will thrown to the pending thread.
Socket channels are thread-safe, no more than one thread can read or write at
given time. The connect
and finishConnect
methods are concurrent each other, when they are processing, other read and
write will block.
SocketChannel(SelectorProvider selectorProvider) | ||||||
Constructor for this class. |
abstract | boolean | connect(SocketAddress address) | ||||
Connect the socket to remote address. | ||||||
abstract | boolean | finishConnect() | ||||
Complete the connection. | ||||||
abstract | boolean | isConnected() | ||||
Answer whether this channel's socket is connected or not. | ||||||
abstract | boolean | isConnectionPending() | ||||
Answer whether this channel's socket is in connecting or not. | ||||||
static | SocketChannel | open(SocketAddress address) | ||||
Create a socket channel and connect it to a socket address. | ||||||
static | SocketChannel | open() | ||||
Create a open and not-connected socket channel. | ||||||
abstract | long | read(ByteBuffer[] targets, int offset, int length) | ||||
Reads bytes from the channel into a subset of the given buffers. | ||||||
abstract | int | read(ByteBuffer target) | ||||
Reads bytes from the channel into the given buffer. | ||||||
synchronized | final | long | read(ByteBuffer[] targets) | |||
Reads bytes from the channel into all the given buffers. | ||||||
abstract | Socket | socket() | ||||
Return the related socket of this channel, which won't declare public
methods that not declared in Socket . |
||||||
final | int | validOps() | ||||
Get the valid operations of this channel. | ||||||
abstract | long | write(ByteBuffer[] sources, int offset, int length) | ||||
Writes a subset of the given bytes from the buffers to the channel. | ||||||
synchronized | final | long | write(ByteBuffer[] sources) | |||
Writes bytes from all the given buffers to the channel. | ||||||
abstract | int | write(ByteBuffer source) | ||||
Writes bytes from the given buffer to the channel. |
selectorProvider | A instance of SelectorProvider |
---|
If the channel is blocking, this method will suspend before connection
finished or an I/O exception. If the channel is non-blocking, this method
will return true
if the connection is finished at once or
return false
and the connection must wait
finishConnect
to finished otherwise.
This method can be called at any moment, and can block other read and write operations while connecting.
This method just execute the same security checks as the connect method
of the Socket
class.
address | The address to be connected. |
---|
true
if connection is finished,false
otherwise.AlreadyConnectedException | If the channel is connected already. |
---|---|
ConnectionPendingException | A non-blocking connecting is doing on this channel. |
ClosedChannelException | If the channel is already closed. |
AsynchronousCloseException | If the channel is closed by another thread while this method is in operation. |
ClosedByInterruptException | If another thread interrupts the calling thread while the operation is in progress. The calling thread will have the interrupt state set, and the channel will be closed. |
UnresolvedAddressException | If the address is not resolved. |
UnsupportedAddressTypeException | If the address type is not supported. |
SecurityException | If there is a security manager, and the address is not permitted to access. |
IOException | Some other IO error occurred. |
This method is used when the channel is connectable to finish the
connection, and the connectable status of a channel means the channel is
after initiating in non-blocking mode and calling its
connect
method. It will throw related
IOException
if the connection failed.
This method will return true
if the connection is finished
already, and return false
if the channel is non-blocking
and the connection is not finished yet.
If the channel is in blocking mode, this method will suspend, and return
true
for connection finished or throw some exception
otherwise. The channel will be closed if the connection failed and this
method thrown some exception.
This method can be called at any moment, and can block other read and write operations while connecting.
true
if the connection is successfully finished,
false
otherwise.NoConnectionPendingException | If the channel is not connected and the connection is not initiated. |
---|---|
ClosedChannelException | If the channel is already closed. |
AsynchronousCloseException | If the channel is closed by another thread while this method is in operation. |
ClosedByInterruptException | If another thread interrupts the calling thread while the operation is in progress. The calling thread will have the interrupt state set, and the channel will be closed. |
IOException | Some other IO error occurred. |
true
for this channel's socket is connected;
false
otherwise.
true
for the connection is initiated but not
finished; false
otherwise.
This method perform just as open
method following by the
connect
method.
address | The socket address to be connected. |
---|
AsynchronousCloseException | If the channel is closed by another thread while this method is in operation. |
---|---|
ClosedByInterruptException | If another thread interrupts the calling thread while the operation is in progress. The calling thread will have the interrupt state set, and the channel will be closed. |
UnresolvedAddressException | If the address is not resolved. |
UnsupportedAddressTypeException | If the address type is not supported. |
SecurityException | If there is a security manager, and the address is not permitted to access. |
IOException | Some other IO error occurred. |
This channel is got by openSocketChannel
method of the
default SelectorProvider
instance.
IOException | If some IO problem occurs. |
---|
This method attempts to read all of the remaining()
bytes
from length
byte buffers, in order, starting at
targets[offset]
. The number of bytes actually read is
returned.
If a read operation is in progress, subsequent threads will block until the read is completed, and will then contend for the ability to read.
targets | the array of byte buffers into which the bytes will be read. |
---|---|
offset | the index of the first buffer to read. |
length | the maximum number of buffers to read. |
NotYetConnectedException | If the channel is not connected yet. |
---|---|
ClosedChannelException | If the channel is already closed. |
AsynchronousCloseException | If the channel is closed by another thread while this method is in operation. |
ClosedByInterruptException | If another thread interrupts the calling thread while the operation is in progress. The calling thread will have the interrupt state set, and the channel will be closed. |
IOException | Some other IO error occurred. |
The maximum number of bytes that will be read is the
remaining()
number of bytes in the buffer when the method
invoked. The bytes will be read into the buffer starting at the buffer's
position
.
The call may block if other threads are also attempting to read on the same channel.
Upon completion, the buffer's position()
is updated to the
end of the bytes that were read. The buffer's limit()
is
unmodified.
target | The byte buffer to receive the bytes. |
---|
NotYetConnectedException | If the channel is not connected yet. |
---|---|
ClosedChannelException | If the channel is already closed. |
AsynchronousCloseException | If the channel is closed by another thread while this method is in operation. |
ClosedByInterruptException | If another thread interrupts the calling thread while the operation is in progress. The calling thread will have the interrupt state set, and the channel will be closed. |
IOException | Some other IO error occurred. |
This method is equivalent to:
read(targets, 0, targets.length);
targets | the array of byte buffers to receive the bytes being read. |
---|
NotYetConnectedException | If the channel is not connected yet. |
---|---|
ClosedChannelException | If the channel is already closed. |
AsynchronousCloseException | If the channel is closed by another thread while this method is in operation. |
ClosedByInterruptException | If another thread interrupts the calling thread while the operation is in progress. The calling thread will have the interrupt state set, and the channel will be closed. |
IOException | Some other IO error occurred. |
Socket
.
SelectionKey.OP_CONNECT
|
SelectionKey.OP_READ
| SelectionKey.OP_WRITE
).
This method attempts to write all of the remaining()
bytes
from length
byte buffers, in order, starting at
sources[offset]
. The number of bytes actually written is
returned.
If a write operation is in progress, subsequent threads will block until the write is completed, and will then contend for the ability to write.
sources | the array of byte buffers containing the source of remaining bytes that will be attempted to be written. |
---|---|
offset | the index of the first buffer to write. |
length | the number of buffers to write. |
NotYetConnectedException | If the channel is not connected yet. |
---|---|
ClosedChannelException | If the channel is already closed. |
AsynchronousCloseException | If the channel is closed by another thread while this method is in operation. |
ClosedByInterruptException | If another thread interrupts the calling thread while the operation is in progress. The calling thread will have the interrupt state set, and the channel will be closed. |
IOException | Some other IO error occurred. |
This method is equivalent to:
write(buffers, 0, buffers.length);
sources | the buffers containing bytes to be written. |
---|
NotYetConnectedException | If the channel is not connected yet. |
---|---|
ClosedChannelException | If the channel is already closed. |
AsynchronousCloseException | If the channel is closed by another thread while this method is in operation. |
ClosedByInterruptException | If another thread interrupts the calling thread while the operation is in progress. The calling thread will have the interrupt state set, and the channel will be closed. |
IOException | Some other IO error occurred. |
The maximum number of bytes that will be written is the
remaining()
number of bytes in the buffer when the method
invoked. The bytes will be written from the buffer starting at the
buffer's position
.
The call may block if other threads are also attempting to write on the same channel.
Upon completion, the buffer's position()
is updated to the
end of the bytes that were written. The buffer's limit()
is unmodified.
source | the byte buffer containing the bytes to be written. |
---|
NotYetConnectedException | If the channel is not connected yet. |
---|---|
ClosedChannelException | If the channel is already closed. |
AsynchronousCloseException | If the channel is closed by another thread while this method is in operation. |
ClosedByInterruptException | If another thread interrupts the calling thread while the operation is in progress. The calling thread will have the interrupt state set, and the channel will be closed. |
IOException | Some other IO error occurred. |
Copyright 2007 Google Inc. | Build 0.9_r1-98467 - 14 Aug 2008 18:56 |