java.nio.channels
Class ServerSocketChanneljava.lang.Object | +--java.nio.channels.spi.AbstractInterruptibleChannel | +--java.nio.channels.SelectableChannel | +--java.nio.channels.spi.AbstractSelectableChannel | +--java.nio.channels.ServerSocketChannel
- All Implemented Interfaces:
- 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 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
Methods inherited from class java.nio.channels.SelectableChannel register
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
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 - 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 in class SelectableChannel
- 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 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 - If this channel is closed
- AsynchronousCloseException - If another thread closes this channel while the accept operation is in progress
- ClosedByInterruptException - 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 - If this channel's socket has not yet been bound
- SecurityException - If a security manager has been installed and it does not permit access to the remote endpoint of the new connection
- IOException - If some other I/O error occurs