NetworkChannel

AI-generated Key Takeaways

• NetworkChannel represents a channel to a network socket, enabling communication over a network.

• It provides methods for binding to a local address, getting the bound address, and managing socket options.

• Implementations of NetworkChannel include SocketChannel, ServerSocketChannel, DatagramChannel, and others for various network communication scenarios.

• Key operations include bind, getLocalAddress, getOption, setOption, and supportedOptions for managing the channel's connection and configuration.

• This interface extends the Channel interface, inheriting functionalities for closing and checking the channel's open state.

public interface NetworkChannel implements Channel

Known Indirect Subclasses AsynchronousServerSocketChannel, AsynchronousSocketChannel, DatagramChannel, MulticastChannel, ServerSocketChannel, SocketChannel AsynchronousServerSocketChannel An asynchronous channel for stream-oriented listening sockets.  AsynchronousSocketChannel An asynchronous channel for stream-oriented connecting sockets.  DatagramChannel A selectable channel for datagram-oriented sockets.  MulticastChannel A network channel that supports Internet Protocol (IP) multicasting.  ServerSocketChannel A selectable channel for stream-oriented listening sockets.  SocketChannel A selectable channel for stream-oriented connecting sockets.

A channel to a network socket.

A channel that implements this interface is a channel to a network socket. The bind method is used to bind the socket to a local address, the getLocalAddress method returns the address that the socket is bound to, and the setOption and getOption methods are used to set and query socket options. An implementation of this interface should specify the socket options that it supports.

The bind and setOption methods that do not otherwise have a value to return are specified to return the network channel upon which they are invoked. This allows method invocations to be chained. Implementations of this interface should specialize the return type so that method invocations on the implementation class can be chained.

Public Method Summary

abstract NetworkChannel	bind(SocketAddress local) Binds the channel's socket to a local address.
abstract SocketAddress	getLocalAddress() Returns the socket address that this channel's socket is bound to.
abstract <T> T	getOption(SocketOption<T> name) Returns the value of a socket option.
abstract <T> NetworkChannel	setOption(SocketOption<T> name, T value) Sets the value of a socket option.
abstract Set<SocketOption<?>>	supportedOptions() Returns a set of the socket options supported by this channel.

Inherited Method Summary

From interface java.nio.channels.Channel

abstract void	close() Closes this channel.
abstract boolean	isOpen() Tells whether or not this channel is open.

From interface java.io.Closeable

abstract void

close() Closes this stream and releases any system resources associated with it.

From interface java.lang.AutoCloseable

abstract void

close() Closes this resource, relinquishing any underlying resources.

Public Methods

public abstract NetworkChannel bind (SocketAddress local)

Binds the channel's socket to a local address.

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 channel is closed. If the local parameter has the value null then the socket will be bound to an address that is assigned automatically.

Parameters

local	The address to bind the socket, or null to bind the socket to an automatically assigned socket address

Returns

• This channel

Throws

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

See Also

• getLocalAddress()

public abstract SocketAddress getLocalAddress ()

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 InetSocketAddress.

Returns

• The socket address that the socket is bound to, or null if the channel's socket is not bound

Throws

ClosedChannelException	If the channel is closed
IOException	If an I/O error occurs

public abstract T getOption (SocketOption<T> name)

Returns the value of a socket option.

Parameters

name	The socket option

Returns

• The value of the socket option. A value of null may be a valid value for some socket options.

Throws

UnsupportedOperationException	If the socket option is not supported by this channel
ClosedChannelException	If this channel is closed
IOException	If an I/O error occurs

See Also

• StandardSocketOptions

public abstract NetworkChannel setOption (SocketOption<T> name, T value)

Sets the value of a socket option.

Parameters

name	The socket option
value	The value of the socket option. A value of null may be a valid value for some socket options.

Returns

• This channel

Throws

UnsupportedOperationException	If the socket option is not supported by this channel
IllegalArgumentException	If the value is not a valid value for this socket option
ClosedChannelException	If this channel is closed
IOException	If an I/O error occurs

See Also

• StandardSocketOptions

public abstract Set<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.

Returns

• A set of the socket options supported by this channel