ServerSocketChannel
public
abstract
class
ServerSocketChannel
extends AbstractSelectableChannel
implements
NetworkChannel
java.lang.Object | ||||
↳ | java.nio.channels.spi.AbstractInterruptibleChannel | |||
↳ | java.nio.channels.SelectableChannel | |||
↳ | java.nio.channels.spi.AbstractSelectableChannel | |||
↳ | java.nio.channels.ServerSocketChannel |
A selectable channel for stream-oriented listening sockets.
A server-socket channel is created by invoking the open
method of this class. It is not possible to create a channel for an arbitrary,
pre-existing ServerSocket
. 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 defined by this class.
Socket options are configured using the setOption
method. Server-socket channels support the following options:
Additional (implementation specific) options may also be supported.
Option Name Description SO_RCVBUF
The size of the socket receive buffer SO_REUSEADDR
Re-use address
Server-socket channels are safe for use by multiple concurrent threads.
Summary
Protected constructors | |
---|---|
ServerSocketChannel(SelectorProvider provider)
Initializes a new instance of this class. |
Public methods | |
---|---|
abstract
SocketChannel
|
accept()
Accepts a connection made to this channel's socket. |
abstract
ServerSocketChannel
|
bind(SocketAddress local, int backlog)
Binds the channel's socket to a local address and configures the socket to listen for connections. |
final
ServerSocketChannel
|
bind(SocketAddress local)
Binds the channel's socket to a local address and configures the socket to listen for connections. |
abstract
SocketAddress
|
getLocalAddress()
Returns the socket address that this channel's socket is bound to.
If there is a security manager set, its |
static
ServerSocketChannel
|
open()
Opens a server-socket channel. |
abstract
<T>
ServerSocketChannel
|
setOption(SocketOption<T> name, T value)
Sets the value of a socket option. |
abstract
ServerSocket
|
socket()
Retrieves a server socket associated with this channel. |
final
int
|
validOps()
Returns an operation set identifying this channel's supported operations. |
Inherited methods | |
---|---|
Protected constructors
ServerSocketChannel
protected ServerSocketChannel (SelectorProvider provider)
Initializes a new instance of this class.
Parameters | |
---|---|
provider |
SelectorProvider : The provider that created this channel |
Public methods
accept
public abstract SocketChannel accept ()
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 | |
---|---|
SocketChannel |
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 |
bind
public abstract ServerSocketChannel bind (SocketAddress local, int backlog)
Binds the channel's socket to a local address and configures the socket to listen for connections.
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.
The backlog
parameter is the maximum number of pending
connections on the socket. Its exact semantics are implementation specific.
In particular, an implementation may impose a maximum length or may choose
to ignore the parameter altogther. If the backlog
parameter has
the value 0
, or a negative value, then an implementation specific
default is used.
Parameters | |
---|---|
local |
SocketAddress : The address to bind the socket, or null to bind to an
automatically assigned socket address |
backlog |
int : The maximum number of pending connections |
Returns | |
---|---|
ServerSocketChannel |
This channel |
Throws | |
---|---|
AlreadyBoundException |
If the socket is already bound |
UnsupportedAddressTypeException |
If the type of the given address is not supported |
ClosedChannelException |
If this channel is closed |
IOException |
If some other I/O error occurs |
SecurityException |
If a security manager has been installed and its checkListen method denies the
operation |
bind
public final ServerSocketChannel bind (SocketAddress local)
Binds the channel's socket to a local address and configures the socket to listen for connections.
An invocation of this method is equivalent to the following:
bind(local, 0);
Parameters | |
---|---|
local |
SocketAddress : The local address to bind the socket, or null to bind
to an automatically assigned socket address |
Returns | |
---|---|
ServerSocketChannel |
This channel |
Throws | |
---|---|
AlreadyBoundException |
|
UnsupportedAddressTypeException |
|
ClosedChannelException |
|
IOException |
|
SecurityException |
If a security manager has been installed and its checkListen method denies the
operation |
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
.
If there is a security manager set, its checkConnect
method is
called with the local address and -1
as its arguments to see
if the operation is allowed. If the operation is not allowed,
a SocketAddress
representing the
loopback
address and the
local port of the channel's socket is returned.
Returns | |
---|---|
SocketAddress |
The SocketAddress that the socket is bound to, or the
SocketAddress representing the loopback address if
denied by the security manager, or null if the
channel's socket is not bound |
Throws | |
---|---|
ClosedChannelException |
|
IOException |
open
public static ServerSocketChannel open ()
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 | |
---|---|
ServerSocketChannel |
A new socket channel |
Throws | |
---|---|
IOException |
If an I/O error occurs |
setOption
public abstract ServerSocketChannel setOption (SocketOption<T> name, T value)
Sets the value of a socket option.
Parameters | |
---|---|
name |
SocketOption : The socket option |
value |
T : The value of the socket option. A value of null may be
a valid value for some socket options. |
Returns | |
---|---|
ServerSocketChannel |
This channel |
Throws | |
---|---|
UnsupportedOperationException |
|
IllegalArgumentException |
|
ClosedChannelException |
|
IOException |
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 | |
---|---|
ServerSocket |
A server socket associated with this channel |
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
.
Returns | |
---|---|
int |
The valid-operation set |