- All Implemented Interfaces:
Closeable
,AutoCloseable
,Channel
,InterruptibleChannel
,NetworkChannel
public abstract class ServerSocketChannel extends AbstractSelectableChannel implements NetworkChannel
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.
- Since:
- 1.4
-
Constructor Summary
Constructors 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.static ServerSocketChannel
open(ProtocolFamily family)
Opens a server-socket channel.Thefamily
parameter specifies theprotocol family
of the channel's socket.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.NetworkChannel
getOption, supportedOptions
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Constructor Details
-
ServerSocketChannel
Initializes a new instance of this class.- Parameters:
provider
- The provider that created this channel
-
-
Method Details
-
open
Opens a server-socket channel.The new channel is created by invoking the
openServerSocketChannel
method of the system-wide defaultSelectorProvider
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
-
open
Opens a server-socket channel.Thefamily
parameter specifies theprotocol family
of the channel's socket.The new channel is created by invoking the
openServerSocketChannel(ProtocolFamily)
method of the system-wide defaultSelectorProvider
object.- Parameters:
family
- The protocol family- Returns:
- A new socket channel
- Throws:
UnsupportedOperationException
- If the specified protocol family is not supported. For example, suppose the parameter is specified asStandardProtocolFamily.INET6
but IPv6 is not enabled on the platform.IOException
- If an I/O error occurs- Since:
- 15
-
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
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 boundUnsupportedAddressTypeException
- If the type of the given address is not supportedClosedChannelException
- If the channel is closedIOException
- If some other I/O error occursSecurityException
- If a security manager has been installed and itscheckListen
method denies the operation- Since:
- 1.7
- See Also:
NetworkChannel.getLocalAddress()
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bind
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 thebacklog
parameter has the value0
, 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 addressbacklog
- The maximum number of pending connections- Returns:
- This channel
- Throws:
AlreadyBoundException
- If the socket is already boundUnsupportedAddressTypeException
- If the type of the given address is not supportedClosedChannelException
- If this channel is closedIOException
- If some other I/O error occursSecurityException
- 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 IOExceptionDescription 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 optionvalue
- 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 channelIllegalArgumentException
- If the value is not a valid value for this socket optionClosedChannelException
- If this channel is closedIOException
- If an I/O error occurs- Since:
- 1.7
- See Also:
StandardSocketOptions
-
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
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 theServerSocket
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'scheckAccept
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 closedAsynchronousCloseException
- If another thread closes this channel while the accept operation is in progressClosedByInterruptException
- 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 statusNotYetBoundException
- If this channel's socket has not yet been boundSecurityException
- If a security manager has been installed and it does not permit access to the remote endpoint of the new connectionIOException
- If some other I/O error occurs
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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 typeInetSocketAddress
.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, aSocketAddress
representing theloopback
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 closedIOException
- If an I/O error occurs
-