implements AsynchronousChannel NetworkChannel
An asynchronous channel for stream-oriented listening sockets.
An asynchronous server-socket channel is created by invoking the
open
method of this class.
A newly-created asynchronous server-socket channel is open but not yet bound.
It can be bound to a local address and configured to listen for connections
by invoking the bind
method. Once bound,
the accept
method
is used to initiate the accepting of connections to the channel's socket.
An attempt to invoke the accept method on an unbound channel will
cause a NotYetBoundException
to be thrown.
Channels of this type are safe for use by multiple concurrent threads
though at most one accept operation can be outstanding at any time.
If a thread initiates an accept operation before a previous accept operation
has completed then an AcceptPendingException
will be thrown.
Socket options are configured using the setOption
method. Channels of this type 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
Usage Example:
final AsynchronousServerSocketChannel listener = AsynchronousServerSocketChannel.open().bind(new InetSocketAddress(5000)); listener.accept(null, new CompletionHandler<AsynchronousSocketChannel,Void>() { public void completed(AsynchronousSocketChannel ch, Void att) { // accept the next connection listener.accept(null, this); // handle this connection handle(ch); } public void failed(Throwable exc, Void att) { ... } });
Protected Constructor Summary
AsynchronousServerSocketChannel(AsynchronousChannelProvider provider)
Initializes a new instance of this class.
|
Public Method Summary
abstract <A> void |
accept(A attachment, CompletionHandler<AsynchronousSocketChannel, ? super A> handler)
Accepts a connection.
|
abstract Future<AsynchronousSocketChannel> |
accept()
Accepts a connection.
|
abstract AsynchronousServerSocketChannel |
bind(SocketAddress local, int backlog)
Binds the channel's socket to a local address and configures the socket to
listen for connections.
|
final AsynchronousServerSocketChannel |
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 AsynchronousServerSocketChannel | |
static AsynchronousServerSocketChannel |
open()
Opens an asynchronous server-socket channel.
|
final AsynchronousChannelProvider |
provider()
Returns the provider that created this channel.
|
abstract <T> AsynchronousServerSocketChannel |
Inherited Method Summary
Protected Constructors
protected AsynchronousServerSocketChannel (AsynchronousChannelProvider provider)
Initializes a new instance of this class.
Parameters
provider | The provider that created this channel |
---|
Public Methods
public abstract void accept (A attachment, CompletionHandler<AsynchronousSocketChannel, ? super A> handler)
Accepts a connection.
This method initiates an asynchronous operation to accept a
connection made to this channel's socket. The handler
parameter is
a completion handler that is invoked when a connection is accepted (or
the operation fails). The result passed to the completion handler is
the AsynchronousSocketChannel
to the new connection.
When a new connection is accepted then the resulting AsynchronousSocketChannel
will be bound to the same AsynchronousChannelGroup
as this channel. If the group is shutdown
and a connection is accepted,
then the connection is closed, and the operation completes with an IOException
and cause ShutdownChannelGroupException
.
To allow for concurrent handling of new connections, the completion handler is not invoked directly by the initiating thread when a new connection is accepted immediately (see Threading).
If a security manager has been installed then it verifies that the
address and port number of the connection's remote endpoint are permitted
by the security manager's checkAccept
method. The permission check is performed with privileges that are restricted
by the calling context of this method. If the permission check fails then
the connection is closed and the operation completes with a SecurityException
.
Parameters
attachment | The object to attach to the I/O operation; can be null |
---|---|
handler | The handler for consuming the result |
Throws
AcceptPendingException | If an accept operation is already in progress on this channel |
---|---|
NotYetBoundException | If this channel's socket has not yet been bound |
ShutdownChannelGroupException | If the channel group has terminated |
public abstract Future<AsynchronousSocketChannel> accept ()
Accepts a connection.
This method initiates an asynchronous operation to accept a
connection made to this channel's socket. The method behaves in exactly
the same manner as the accept(Object, CompletionHandler)
method
except that instead of specifying a completion handler, this method
returns a Future
representing the pending result. The Future
's get
method returns the AsynchronousSocketChannel
to the new connection on successful completion.
Returns
- a
Future
object representing the pending result
Throws
AcceptPendingException | If an accept operation is already in progress on this channel |
---|---|
NotYetBoundException | If this channel's socket has not yet been bound |
public abstract AsynchronousServerSocketChannel 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 associated 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 | The local address to bind the socket, or null to bind
to an automatically assigned socket address |
---|---|
backlog | The maximum number of pending connections |
Returns
- This channel
Throws
AlreadyBoundException | If the socket is already bound |
---|---|
UnsupportedAddressTypeException | If the type of the given address is not supported |
SecurityException | If a security manager has been installed and its checkListen method denies the operation |
ClosedChannelException | If the channel is closed |
IOException | If some other I/O error occurs |
public final AsynchronousServerSocketChannel 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 | The local address to bind the socket, or null to bind to an automatically assigned socket address |
---|
Returns
- This channel
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
- The
SocketAddress
that the socket is bound to, or theSocketAddress
representing the loopback address if denied by the security manager, ornull
if the channel's socket is not bound
public static AsynchronousServerSocketChannel open (AsynchronousChannelGroup group)
Opens an asynchronous server-socket channel.
The new channel is created by invoking the openAsynchronousServerSocketChannel
method on the AsynchronousChannelProvider
object that created
the given group. If the group parameter is null then the
resulting channel is created by the system-wide default provider, and
bound to the default group.
Parameters
group | The group to which the newly constructed channel should be bound, or null for the default group |
---|
Returns
- A new asynchronous server socket channel
Throws
ShutdownChannelGroupException | If the channel group is shutdown |
---|---|
IOException | If an I/O error occurs |
public static AsynchronousServerSocketChannel open ()
Opens an asynchronous server-socket channel.
This method returns an asynchronous server socket channel that is bound to the default group. This method is equivalent to evaluating the expression:
open((AsynchronousChannelGroup)null);
Returns
- A new asynchronous server socket channel
Throws
IOException | If an I/O error occurs |
---|
public final AsynchronousChannelProvider provider ()
Returns the provider that created this channel.
Returns
- The provider that created this channel
public abstract AsynchronousServerSocketChannel 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