Added in API level 1

Channel

interface Channel : Closeable

java.nio.channels.Channel

Known Direct Subclasses AbstractInterruptibleChannel, AsynchronousChannel, Channel, InterruptibleChannel, NetworkChannel, ReadableByteChannel, SelectableChannel, SensorDirectChannel, WritableByteChannel AbstractInterruptibleChannel Base implementation class for interruptible channels. AsynchronousChannel A channel that supports asynchronous I/O operations. Channel Instances of this class represent an ISO/IEC 7816-4 channel opened to a Secure Element. InterruptibleChannel A channel that can be asynchronously closed and interrupted. NetworkChannel A channel to a network socket. ReadableByteChannel A channel that can read bytes. SelectableChannel A channel that can be multiplexed via a Selector. SensorDirectChannel Class representing a sensor direct channel. WritableByteChannel A channel that can write bytes.

Known Indirect Subclasses AbstractInterruptibleChannel, AbstractSelectableChannel, AbstractSelectableChannel, AbstractSelectableChannel, AsynchronousByteChannel, AsynchronousFileChannel, AsynchronousServerSocketChannel, AsynchronousServerSocketChannel, AsynchronousSocketChannel, AsynchronousSocketChannel, ByteChannel, ByteChannel, and 43 others. AbstractInterruptibleChannel Base implementation class for interruptible channels. AbstractSelectableChannel Base implementation class for selectable channels. AbstractSelectableChannel Base implementation class for selectable channels. AbstractSelectableChannel Base implementation class for selectable channels. AsynchronousByteChannel An asynchronous channel that can read and write bytes. AsynchronousFileChannel An asynchronous channel for reading, writing, and manipulating a file. AsynchronousServerSocketChannel An asynchronous channel for stream-oriented listening sockets. AsynchronousServerSocketChannel An asynchronous channel for stream-oriented listening sockets. AsynchronousSocketChannel An asynchronous channel for stream-oriented connecting sockets. AsynchronousSocketChannel An asynchronous channel for stream-oriented connecting sockets. ByteChannel A channel that can read and write bytes. ByteChannel A channel that can read and write bytes. DatagramChannel A selectable channel for datagram-oriented sockets. DatagramChannel A selectable channel for datagram-oriented sockets. DatagramChannel A selectable channel for datagram-oriented sockets. DatagramChannel A selectable channel for datagram-oriented sockets. DatagramChannel A selectable channel for datagram-oriented sockets. DatagramChannel A selectable channel for datagram-oriented sockets. DatagramChannel A selectable channel for datagram-oriented sockets. DatagramChannel A selectable channel for datagram-oriented sockets. FileChannel A channel for reading, writing, mapping, and manipulating a file. FileChannel A channel for reading, writing, mapping, and manipulating a file. FileChannel A channel for reading, writing, mapping, and manipulating a file. FileChannel A channel for reading, writing, mapping, and manipulating a file. FileChannel A channel for reading, writing, mapping, and manipulating a file. FileChannel A channel for reading, writing, mapping, and manipulating a file. GatheringByteChannel A channel that can write bytes from a sequence of buffers. MulticastChannel A network channel that supports Internet Protocol (IP) multicasting. Pipe.SinkChannel A channel representing the writable end of a Pipe. Pipe.SinkChannel A channel representing the writable end of a Pipe. Pipe.SinkChannel A channel representing the writable end of a Pipe. Pipe.SinkChannel A channel representing the writable end of a Pipe. Pipe.SinkChannel A channel representing the writable end of a Pipe. Pipe.SourceChannel A channel representing the readable end of a Pipe. Pipe.SourceChannel A channel representing the readable end of a Pipe. Pipe.SourceChannel A channel representing the readable end of a Pipe. Pipe.SourceChannel A channel representing the readable end of a Pipe. Pipe.SourceChannel A channel representing the readable end of a Pipe. ScatteringByteChannel A channel that can read bytes into a sequence of buffers. SeekableByteChannel A byte channel that maintains a current position and allows the position to be changed. SeekableByteChannel A byte channel that maintains a current position and allows the position to be changed. SelectableChannel A channel that can be multiplexed via a Selector. SelectableChannel A channel that can be multiplexed via a Selector. ServerSocketChannel A selectable channel for stream-oriented listening sockets. ServerSocketChannel A selectable channel for stream-oriented listening sockets. ServerSocketChannel A selectable channel for stream-oriented listening sockets. ServerSocketChannel A selectable channel for stream-oriented listening sockets. SocketChannel A selectable channel for stream-oriented connecting sockets. SocketChannel A selectable channel for stream-oriented connecting sockets. SocketChannel A selectable channel for stream-oriented connecting sockets. SocketChannel A selectable channel for stream-oriented connecting sockets. SocketChannel A selectable channel for stream-oriented connecting sockets. SocketChannel A selectable channel for stream-oriented connecting sockets. SocketChannel A selectable channel for stream-oriented connecting sockets. SocketChannel A selectable channel for stream-oriented connecting sockets.

A nexus for I/O operations.

A channel represents an open connection to an entity such as a hardware device, a file, a network socket, or a program component that is capable of performing one or more distinct I/O operations, for example reading or writing.

A channel is either open or closed. A channel is open upon creation, and once closed it remains closed. Once a channel is closed, any attempt to invoke an I/O operation upon it will cause a ClosedChannelException to be thrown. Whether or not a channel is open may be tested by invoking its isOpen method.

Channels are, in general, intended to be safe for multithreaded access as described in the specifications of the interfaces and classes that extend and implement this interface.

Summary

Public methods
abstract Unit	close() Closes this channel.
abstract Boolean	isOpen() Tells whether or not this channel is open.

Public methods

close

Added in API level 1

abstract fun close(): Unit

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.

Exceptions
java.lang.Exception	if this resource cannot be closed
java.io.IOException	If an I/O error occurs

isOpen

Added in API level 1

abstract fun isOpen(): Boolean

Tells whether or not this channel is open.

Return
Boolean	true if, and only if, this channel is open