Added in API level 26

AsynchronousServerSocketChannel

abstract class AsynchronousServerSocketChannel : AsynchronousChannel, NetworkChannel

kotlin.Any
↳	java.nio.channels.AsynchronousServerSocketChannel

An asynchronous channel for stream-oriented listening sockets.

An asynchronous server-socket channel is created by invoking the #open method of this class. A newly-created asynchronous server-socket channel is open but not yet bound. It can be bound to a local address and configured to listen for connections by invoking the bind method. Once bound, the accept method is used to initiate the accepting of connections to the channel's socket. An attempt to invoke the accept method on an unbound channel will cause a NotYetBoundException to be thrown.

Channels of this type are safe for use by multiple concurrent threads though at most one accept operation can be outstanding at any time. If a thread initiates an accept operation before a previous accept operation has completed then an AcceptPendingException will be thrown.

Socket options are configured using the setOption method. Channels of this type support the following options:

Socket options

Option Name	Description
`SO_RCVBUF`	The size of the socket receive buffer
`SO_REUSEADDR`	Re-use address

Additional (implementation specific) options may also be supported.

Usage Example:

final AsynchronousServerSocketChannel listener =
       AsynchronousServerSocketChannel.open().bind(new InetSocketAddress(5000));
 
   listener.accept(null, new CompletionHandler<AsynchronousSocketChannel,Void>() {
       public void completed(AsynchronousSocketChannel ch, Void att) {
           // accept the next connection
           listener.accept(null, this);
 
           // handle this connection
           handle(ch);
       }
       public void failed(Throwable exc, Void att) {
           ...
       }
   });

Summary

Protected constructors
`AsynchronousServerSocketChannel(provider: AsynchronousChannelProvider!)` Initializes a new instance of this class.

Public methods
abstract Future<AsynchronousSocketChannel!>!	`accept()` Accepts a connection.
abstract Unit	`accept(attachment: A, handler: CompletionHandler<AsynchronousSocketChannel!, in A>!)` Accepts a connection.
AsynchronousServerSocketChannel!	`bind(local: SocketAddress!)` Binds the channel's socket to a local address and configures the socket to listen for connections.
abstract AsynchronousServerSocketChannel!	`bind(local: SocketAddress!, backlog: Int)` Binds the channel's socket to a local address and configures the socket to listen for connections.
abstract SocketAddress!	`getLocalAddress()` Returns the socket address that this channel's socket is bound to.
open static AsynchronousServerSocketChannel!	`open()` Opens an asynchronous server-socket channel.
open static AsynchronousServerSocketChannel!	`open(group: AsynchronousChannelGroup!)` Opens an asynchronous server-socket channel.
AsynchronousChannelProvider!	`provider()` Returns the provider that created this channel.
abstract AsynchronousServerSocketChannel!	`setOption(name: SocketOption<T>!, value: T)`

Inherited functions

From class AsynchronousChannel

Unit

close()

Closes this channel.

Any outstanding asynchronous operations upon this channel will complete with the exception AsynchronousCloseException. After a channel is closed, further attempts to initiate asynchronous I/O operations complete immediately with cause ClosedChannelException.

This method otherwise behaves exactly as specified by the Channel interface.

From class Channel

Unit

close()

Closes this channel.

After a channel is closed, any further attempt to invoke I/O operations upon it will cause a ClosedChannelException to be thrown.

If this channel is already closed then invoking this method has no effect.

This method may be invoked at any time. If some other thread has already invoked it, however, then another invocation will block until the first invocation is complete, after which it will return without effect.

Boolean

isOpen()

Tells whether or not this channel is open.

Boolean

isOpen()

Tells whether or not this channel is open.

From class NetworkChannel

T

getOption(name: SocketOption<T>!)

Returns the value of a socket option.

MutableSet<SocketOption<*>!>!

supportedOptions()

Returns a set of the socket options supported by this channel.

This method will continue to return the set of options even after the channel has been closed.

Protected constructors

AsynchronousServerSocketChannel

Added in API level 26

protected AsynchronousServerSocketChannel(provider: AsynchronousChannelProvider!)

Initializes a new instance of this class.

Parameters
`provider`	AsynchronousChannelProvider!: The provider that created this channel

Public methods

accept

Added in API level 26

abstract fun accept(): Future<AsynchronousSocketChannel!>!

Accepts a connection.

This method initiates an asynchronous operation to accept a connection made to this channel's socket. The method behaves in exactly the same manner as the accept(java.lang.Object,java.nio.channels.CompletionHandler) method except that instead of specifying a completion handler, this method returns a Future representing the pending result. The Future's get method returns the AsynchronousSocketChannel to the new connection on successful completion.

Return
`Future<AsynchronousSocketChannel!>!`	a `Future` object representing the pending result

Exceptions
`java.nio.channels.AcceptPendingException`	If an accept operation is already in progress on this channel
`java.nio.channels.NotYetBoundException`	If this channel's socket has not yet been bound

accept

Added in API level 26

abstract fun <A : Any!> accept(
    attachment: A, 
    handler: CompletionHandler<AsynchronousSocketChannel!, in A>!
): Unit

Accepts a connection.

This method initiates an asynchronous operation to accept a connection made to this channel's socket. The handler parameter is a completion handler that is invoked when a connection is accepted (or the operation fails). The result passed to the completion handler is the AsynchronousSocketChannel to the new connection.

When a new connection is accepted then the resulting AsynchronousSocketChannel will be bound to the same AsynchronousChannelGroup as this channel. If the group is shutdown and a connection is accepted, then the connection is closed, and the operation completes with an IOException and cause ShutdownChannelGroupException.

To allow for concurrent handling of new connections, the completion handler is not invoked directly by the initiating thread when a new connection is accepted immediately (see Threading).

If a security manager has been installed then it verifies that the address and port number of the connection's remote endpoint are permitted by the security manager's checkAccept method. The permission check is performed with privileges that are restricted by the calling context of this method. If the permission check fails then the connection is closed and the operation completes with a SecurityException.

Parameters
`<A>`	The type of the attachment
`attachment`	A: The object to attach to the I/O operation; can be `null`
`handler`	CompletionHandler<AsynchronousSocketChannel!, in A>!: The handler for consuming the result

Exceptions
`java.nio.channels.AcceptPendingException`	If an accept operation is already in progress on this channel
`java.nio.channels.NotYetBoundException`	If this channel's socket has not yet been bound
`java.nio.channels.ShutdownChannelGroupException`	If the channel group has terminated

bind

Added in API level 26

fun bind(local: SocketAddress!): AsynchronousServerSocketChannel!

Binds the channel's socket to a local address and configures the socket to listen for connections.

An invocation of this method is equivalent to the following:

bind(local, 0);

Parameters
`local`	SocketAddress!: The local address to bind the socket, or `null` to bind to an automatically assigned socket address

Return
`AsynchronousServerSocketChannel!`	This channel

Exceptions
`java.nio.channels.AlreadyBoundException`	If the socket is already bound
`java.nio.channels.UnsupportedAddressTypeException`	If the type of the given address is not supported
`java.nio.channels.ClosedChannelException`	If the channel is closed
`java.io.IOException`	If some other I/O error occurs
`java.lang.SecurityException`	If a security manager is installed and it denies an unspecified permission. An implementation of this interface should specify any required permissions.

bind

Added in API level 26

abstract fun bind(
    local: SocketAddress!, 
    backlog: Int
): AsynchronousServerSocketChannel!

Binds the channel's socket to a local address and configures the socket to listen for connections.

This method is used to establish an association between the socket and a local address. Once an association is established then the socket remains bound until the associated channel is closed.

The backlog parameter is the maximum number of pending connections on the socket. Its exact semantics are implementation specific. In particular, an implementation may impose a maximum length or may choose to ignore the parameter altogther. If the backlog parameter has the value 0, or a negative value, then an implementation specific default is used.

Parameters
`local`	SocketAddress!: The local address to bind the socket, or `null` to bind to an automatically assigned socket address
`backlog`	Int: The maximum number of pending connections

Return
`AsynchronousServerSocketChannel!`	This channel

Exceptions
`java.nio.channels.AlreadyBoundException`	If the socket is already bound
`java.nio.channels.UnsupportedAddressTypeException`	If the type of the given address is not supported
`java.lang.SecurityException`	If a security manager has been installed and its `checkListen` method denies the operation
`java.nio.channels.ClosedChannelException`	If the channel is closed
`java.io.IOException`	If some other I/O error occurs

getLocalAddress

Added in API level 26

abstract fun getLocalAddress(): SocketAddress!

Returns the socket address that this channel's socket is bound to.

Where the channel is bound to an Internet Protocol socket address then the return value from this method is of type .

If there is a security manager set, its checkConnect method is called with the local address and -1 as its arguments to see if the operation is allowed. If the operation is not allowed, a SocketAddress representing the loopback address and the local port of the channel's socket is returned.

Return
`SocketAddress!`	The `SocketAddress` that the socket is bound to, or the `SocketAddress` representing the loopback address if denied by the security manager, or `null` if the channel's socket is not bound

Exceptions
`java.nio.channels.ClosedChannelException`	If the channel is closed
`java.io.IOException`	If an I/O error occurs

open

Added in API level 26

open static fun open(): AsynchronousServerSocketChannel!

Opens an asynchronous server-socket channel.

This method returns an asynchronous server socket channel that is bound to the default group. This method is equivalent to evaluating the expression:

open((AsynchronousChannelGroup)null);

Return
`AsynchronousServerSocketChannel!`	A new asynchronous server socket channel

Exceptions
`java.io.IOException`	If an I/O error occurs

open

Added in API level 26

open static fun open(group: AsynchronousChannelGroup!): AsynchronousServerSocketChannel!

Opens an asynchronous server-socket channel.

The new channel is created by invoking the openAsynchronousServerSocketChannel method on the object that created the given group. If the group parameter is null then the resulting channel is created by the system-wide default provider, and bound to the default group.

Parameters
`group`	AsynchronousChannelGroup!: The group to which the newly constructed channel should be bound, or `null` for the default group

Return
`AsynchronousServerSocketChannel!`	A new asynchronous server socket channel

Exceptions
`java.nio.channels.ShutdownChannelGroupException`	If the channel group is shutdown
`java.io.IOException`	If an I/O error occurs

provider

Added in API level 26

fun provider(): AsynchronousChannelProvider!

Returns the provider that created this channel.

Return
`AsynchronousChannelProvider!`	The provider that created this channel

setOption

Added in API level 26

abstract fun <T : Any!> setOption(
    name: SocketOption<T>!, 
    value: T
): AsynchronousServerSocketChannel!

Parameters
`<T>`	The type of the socket option value
`name`	SocketOption<T>!: The socket option
`value`	T: The value of the socket option. A value of `null` may be a valid value for some socket options.

Return
`AsynchronousServerSocketChannel!`	This channel

Exceptions
`java.lang.UnsupportedOperationException`	If the socket option is not supported by this channel
`java.lang.IllegalArgumentException`	If the value is not a valid value for this socket option
`java.nio.channels.ClosedChannelException`	If this channel is closed
`java.io.IOException`	If an I/O error occurs