Package java.nio.channels

Class ServerSocketChannel

java.lang.Object
java.nio.channels.spi.AbstractInterruptibleChannel
java.nio.channels.SelectableChannel
java.nio.channels.spi.AbstractSelectableChannel
java.nio.channels.ServerSocketChannel
All Implemented Interfaces:
Closeable, AutoCloseable, Channel, InterruptibleChannel
public abstract class ServerSocketChannel
extends AbstractSelectableChannel
A ServerSocketChannel is a partial abstraction of a selectable, stream-oriented listening socket. Binding and manipulation of socket options can only be done through the associated ServerSocket object, returned by calling socket(). ServerSocketChannels can not be constructed for an already existing server-socket, nor can a SocketImpl be assigned.

A server-socket channel is open but not bound when created by the open() method. Calling accept before bound will cause a NotYetBoundException. It can be bound by calling the bind method of a related ServerSocket instance.

  • Constructor Details

    • ServerSocketChannel

      protected ServerSocketChannel​(SelectorProvider selectorProvider)
      Constructs a new ServerSocketChannel.
      Parameters:
      selectorProvider - an instance of SelectorProvider.

  • Method Details

    • open

      public static ServerSocketChannel open() throws IOException
      Creates an open and unbound server-socket channel.

      This channel is created by calling openServerSocketChannel method of the default SelectorProvider instance.

      Returns:
      the new channel which is open but unbound.
      Throws:
      IOException - if an I/O error occurs.

    • validOps

      public final int validOps()
      Gets the valid operations of this channel. Server-socket channels support accepting operation, so this method returns SelectionKey.OP_ACCEPT.
      Specified by:
      validOps in class SelectableChannel
      Returns:
      the operations supported by this channel.
      See Also:
      SelectableChannel.validOps()

    • socket

      public abstract ServerSocket socket()
      Return the server-socket assigned this channel, which does not declare any public methods that are not declared in ServerSocket.
      Returns:
      the server-socket assigned to this channel.

    • accept

      public abstract SocketChannel accept() throws IOException
      Accepts a connection to this server-socket channel.

      This method returns null when this channel is non-blocking and no connection is available, otherwise it blocks until a new connection is available or an I/O error occurs. The socket channel returned by this method will always be in blocking mode.

      This method just executes the same security checks as the accept() method of the ServerSocket class.

      Returns:
      the accepted SocketChannel instance, or null if the channel is non-blocking and no connection is available.
      Throws:
      AsynchronousCloseException - if this channel is closed by another thread while this method is in operation.
      ClosedByInterruptException - if another thread interrupts the calling thread while this operation is in progress. The interrupt state of the calling thread is set and the channel is closed.
      ClosedChannelException - if this channel is closed.
      IOException - if another I/O error occurs.
      NotYetBoundException - if the socket has not yet been bound.