java.nio.channels
interface Channel

All Superinterfaces:

Closeable

All Known Subinterfaces:

InterruptibleChannel, ReadableByteChannel, WritableByteChannel, ScatteringByteChannel, ByteChannel, GatheringByteChannel

All Known Implementing Classes:

AbstractInterruptibleChannel, FileChannel, SelectableChannel, AbstractSelectableChannel, DatagramChannel, Pipe.SinkChannel, Pipe.SourceChannel, ServerSocketChannel, SocketChannel, SelectableChannel

public interface Channel
extends Closeable

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 {@link ClosedChannelException} to be thrown. Whether or not a channel is open may be tested by invoking its {@link #isOpen 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.

close

public void close()
           throws IOException

Closes this channel.

After a channel is closed, any further attempt to invoke I/O operations upon it will cause a {@link 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.

Throws:

IOException - If an I/O error occurs

isOpen

public boolean isOpen()

Tells whether or not this channel is open.

Returns:

true if, and only if, this channel is open