ServerSocketChannel (Java 2 Platform SE 5.0) (original) (raw)

java.nio.channels

Class ServerSocketChannel

java.lang.Object extended by java.nio.channels.spi.AbstractInterruptibleChannel java.nio.channels.SelectableChannel java.nio.channels.spi.AbstractSelectableChannel java.nio.channels.ServerSocketChannel

All Implemented Interfaces:

Closeable, Channel, InterruptibleChannel

public abstract class ServerSocketChannel

extends AbstractSelectableChannel

A selectable channel for stream-oriented listening sockets.

Server-socket channels are not a complete abstraction of listening network sockets. Binding and the manipulation of socket options must be done through an associated ServerSocket object obtained by invoking the socket method. It is not possible to create a channel for an arbitrary, pre-existing server socket, nor is it possible to specify the SocketImpl object to be used by a server socket associated with a server-socket channel.

A server-socket channel is created by invoking the open method of this class. A newly-created server-socket channel is open but not yet bound. An attempt to invoke the accept method of an unbound server-socket channel will cause a NotYetBoundException to be thrown. A server-socket channel can be bound by invoking one of the[bind](../../../java/net/ServerSocket.html#bind%28java.net.SocketAddress, int%29) methods of an associated server socket.

Server-socket channels are safe for use by multiple concurrent threads.

Since:

1.4

Constructor Summary
protected	ServerSocketChannel(SelectorProvider provider) Initializes a new instance of this class.

Method Summary
abstract SocketChannel	accept() Accepts a connection made to this channel's socket.
static ServerSocketChannel	open() Opens a server-socket channel.
abstract ServerSocket	socket() Retrieves a server socket associated with this channel.
int	validOps() Returns an operation set identifying this channel's supported operations.

Methods inherited from class java.nio.channels.spi.AbstractSelectableChannel
blockingLock, configureBlocking, implCloseChannel, implCloseSelectableChannel, implConfigureBlocking, isBlocking, isRegistered, keyFor, provider, [register](../../../java/nio/channels/spi/AbstractSelectableChannel.html#register%28java.nio.channels.Selector, int, java.lang.Object%29)

Methods inherited from class java.nio.channels.SelectableChannel
[register](../../../java/nio/channels/SelectableChannel.html#register%28java.nio.channels.Selector, int%29)

Methods inherited from class java.nio.channels.spi.AbstractInterruptibleChannel
begin, close, end, isOpen

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, [wait](../../../java/lang/Object.html#wait%28long, int%29)

Methods inherited from interface java.nio.channels.Channel
close, isOpen

Constructor Detail

ServerSocketChannel

protected ServerSocketChannel(SelectorProvider provider)

Initializes a new instance of this class.

Method Detail

open

public static ServerSocketChannel open() throws IOException

Opens a server-socket channel.

The new channel is created by invoking the openServerSocketChannel method of the system-wide default SelectorProvider object.

The new channel's socket is initially unbound; it must be bound to a specific address via one of its socket's bind methods before connections can be accepted.

Returns:

A new socket channel

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - If an I/O error occurs

validOps

public final int validOps()

Returns an operation set identifying this channel's supported operations.

Server-socket channels only support the accepting of new connections, so this method returns SelectionKey.OP_ACCEPT.

Specified by:

[validOps](../../../java/nio/channels/SelectableChannel.html#validOps%28%29) in class [SelectableChannel](../../../java/nio/channels/SelectableChannel.html "class in java.nio.channels")

Returns:

The valid-operation set

socket

public abstract ServerSocket socket()

Retrieves a server socket associated with this channel.

The returned object will not declare any public methods that are not declared in the ServerSocket class.

Returns:

A server socket associated with this channel

accept

public abstract SocketChannel accept() throws IOException

Accepts a connection made to this channel's socket.

If this channel is in non-blocking mode then this method will immediately return null if there are no pending connections. Otherwise it will block indefinitely until a new connection is available or an I/O error occurs.

The socket channel returned by this method, if any, will be in blocking mode regardless of the blocking mode of this channel.

This method performs exactly the same security checks as the accept method of the ServerSocket class. That is, if a security manager has been installed then for each new connection this method verifies that the address and port number of the connection's remote endpoint are permitted by the security manager's [checkAccept](../../../java/lang/SecurityManager.html#checkAccept%28java.lang.String, int%29) method.

Returns:

The socket channel for the new connection, or null if this channel is in non-blocking mode and no connection is available to be accepted

Throws:

[ClosedChannelException](../../../java/nio/channels/ClosedChannelException.html "class in java.nio.channels") - If this channel is closed

[AsynchronousCloseException](../../../java/nio/channels/AsynchronousCloseException.html "class in java.nio.channels") - If another thread closes this channel while the accept operation is in progress

[ClosedByInterruptException](../../../java/nio/channels/ClosedByInterruptException.html "class in java.nio.channels") - If another thread interrupts the current thread while the accept operation is in progress, thereby closing the channel and setting the current thread's interrupt status

[NotYetBoundException](../../../java/nio/channels/NotYetBoundException.html "class in java.nio.channels") - If this channel's socket has not yet been bound

[SecurityException](../../../java/lang/SecurityException.html "class in java.lang") - If a security manager has been installed and it does not permit access to the remote endpoint of the new connection

[IOException](../../../java/io/IOException.html "class in java.io") - If some other I/O error occurs

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.