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
,NetworkChannel
public abstract class ServerSocketChannel extends AbstractSelectableChannel implements NetworkChannel
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:
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.
- Since:
- 1.4
Constructor Summary
Modifier | Constructor | Description |
---|---|---|
protected | ServerSocketChannel(SelectorProvider provider) | Initializes a new instance of this class. |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
abstract SocketChannel | accept() | Accepts a connection made to this channel's socket. |
ServerSocketChannel | bind(SocketAddress local) | Binds the channel's socket to a local address and configures the socket to listen for connections. |
abstract ServerSocketChannel | bind(SocketAddress local,
int backlog) | 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. |
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. |
int | validOps() | Returns an operation set identifying this channel's supported operations. |
Methods declared in class java.nio.channels.spi.AbstractSelectableChannel
configureBlocking, implCloseChannel, implCloseSelectableChannel, implConfigureBlocking, provider, register
Methods declared in class java.nio.channels.SelectableChannel
blockingLock, isBlocking, isRegistered, keyFor, register
Methods declared in class java.nio.channels.spi.AbstractInterruptibleChannel
begin, close, end
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods declared in interface java.nio.channels.Channel
isOpen
Methods declared in interface java.nio.channels.NetworkChannel
getOption, supportedOptions
Constructor Detail
ServerSocketChannel
protected ServerSocketChannel(SelectorProvider provider)
Initializes a new instance of this class.
- Parameters:
-
provider
- The provider that created this channel
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 classSelectableChannel
- Returns:
- The valid-operation set
bind
public final ServerSocketChannel bind(SocketAddress local) throws IOException
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);
- Specified by:
-
bind
in interfaceNetworkChannel
- Parameters:
-
local
- The local address to bind the socket, ornull
to bind to an automatically assigned socket address - Returns:
- This channel
- Throws:
-
AlreadyBoundException
- If the socket is already bound -
UnsupportedAddressTypeException
- If the type of the given address is not supported -
ClosedChannelException
- If the channel is closed -
IOException
- If some other I/O error occurs -
SecurityException
- If a security manager has been installed and itscheckListen
method denies the operation - Since:
- 1.7
- See Also:
NetworkChannel.getLocalAddress()
bind
public abstract ServerSocketChannel bind(SocketAddress local, int backlog) throws IOException
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
- The address to bind the socket, ornull
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 -
ClosedChannelException
- If this channel is closed -
IOException
- If some other I/O error occurs -
SecurityException
- If a security manager has been installed and itscheckListen
method denies the operation - Since:
- 1.7
setOption
public abstract <T> ServerSocketChannel setOption(SocketOption<T> name, T value) throws IOException
Description copied from interface: NetworkChannel
Sets the value of a socket option.
- Specified by:
-
setOption
in interfaceNetworkChannel
- Type Parameters:
-
T
- The type of the socket option value - Parameters:
-
name
- The socket option -
value
- The value of the socket option. A value ofnull
may be a valid value for some socket options. - Returns:
- This channel
- Throws:
-
UnsupportedOperationException
- If the socket option is not supported by this channel -
IllegalArgumentException
- If the value is not a valid value for this socket option -
ClosedChannelException
- If this channel is closed -
IOException
- If an I/O error occurs - Since:
- 1.7
- See Also:
StandardSocketOptions
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
getLocalAddress
public abstract SocketAddress getLocalAddress() throws IOException
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.
- Specified by:
-
getLocalAddress
in interfaceNetworkChannel
- 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 - Throws:
-
ClosedChannelException
- If the channel is closed -
IOException
- If an I/O error occurs