Class ServerSocketChannel
- All Implemented Interfaces:
Closeable,AutoCloseable,Channel,InterruptibleChannel,NetworkChannel
A server-socket channel is created by invoking one of the open
methods of this class. The no-arg open method opens a server-socket
channel for an Internet protocol socket. The open(ProtocolFamily)
method is used to open a server-socket channel for a socket of a specified
protocol family. It is not possible to create a channel for an arbitrary,
pre-existing socket. 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 for Internet protocol sockets
support the following options:
Option Name Description SO_RCVBUFThe size of the socket receive buffer SO_REUSEADDRRe-use address
Server-socket channels for Unix domain sockets support:
Option Name Description SO_RCVBUFThe size of the socket receive buffer
Additional (implementation specific) options may also be supported.
Server-socket channels are safe for use by multiple concurrent threads.
- Since:
- 1.4
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Constructor Summary
ConstructorsModifierConstructorDescriptionprotectedServerSocketChannel(SelectorProvider provider) Initializes a new instance of this class. -
Method Summary
Modifier and TypeMethodDescriptionabstract SocketChannelaccept()Accepts a connection made to this channel's socket.final ServerSocketChannelbind(SocketAddress local) Binds the channel's socket to a local address and configures the socket to listen for connections.abstract ServerSocketChannelbind(SocketAddress local, int backlog) Binds the channel's socket to a local address and configures the socket to listen for connections.abstract SocketAddressReturns the socket address that this channel's socket is bound to.static ServerSocketChannelopen()Opens a server-socket channel for an Internet protocol socket.static ServerSocketChannelopen(ProtocolFamily family) Opens a server-socket channel.abstract <T> ServerSocketChannelsetOption(SocketOption<T> name, T value) Sets the value of a socket option.abstract ServerSocketsocket()Retrieves a server socket associated with this channel.final intvalidOps()Returns an operation set identifying this channel's supported operations.Methods declared in class java.nio.channels.spi.AbstractSelectableChannel
blockingLock, configureBlocking, implCloseChannel, implCloseSelectableChannel, implConfigureBlocking, isBlocking, isRegistered, keyFor, provider, registerMethods declared in class java.nio.channels.SelectableChannel
registerMethods declared in class java.nio.channels.spi.AbstractInterruptibleChannel
begin, close, end, isOpenMethods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitMethods declared in interface java.nio.channels.NetworkChannel
getOption, supportedOptions
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Constructor Details
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ServerSocketChannel
Initializes a new instance of this class.- Parameters:
provider- The provider that created this channel
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Method Details
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open
Opens a server-socket channel for an Internet protocol socket.The new channel is created by invoking the
openServerSocketChannelmethod of the system-wide defaultSelectorProviderobject.The new channel's socket is initially unbound; it must be bound to a specific address via one of its socket's
bindmethods before connections can be accepted.- Returns:
- A new socket channel
- Throws:
IOException- If an I/O error occurs- See Also:
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open
Opens a server-socket channel. Thefamilyparameter specifies theprotocol familyof the channel's socket.The new channel is created by invoking the
openServerSocketChannel(ProtocolFamily)method of the system-wide defaultSelectorProviderobject.- 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.INET6but IPv6 is not enabled on the platform.IOException- If an I/O error occurs- Since:
- 15
- See Also:
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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:
validOpsin classSelectableChannel- Returns:
- The valid-operation set
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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:
bindin interfaceNetworkChannel- Parameters:
local- The local address to bind the socket, ornullto 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 occurs- Since:
- 1.7
- See Also:
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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. For Internet protocol sockets, once an association is established then the socket remains bound until the channel is closed.
The
backlogparameter 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 altogether. If thebacklogparameter has the value0, or a negative value, then an implementation specific default is used.- API Note:
- Binding a server socket channel for a Unix Domain socket, creates a
file corresponding to the file path in the
UnixDomainSocketAddress. This file persists after the channel is closed, and must be removed before another socket can bind to the same name. Binding to anulladdress causes the socket to be automatically bound to some unique file in a system temporary location. The associated socket file also persists after the channel is closed. Its name can be obtained from the channel's local socket address. - Implementation Note:
- Each platform enforces an implementation specific, maximum length for the name of a Unix Domain socket. This limitation is enforced when a channel is bound. The maximum length is typically close to and generally not less than 100 bytes. This limitation also applies to automatically bound server socket channels. See the Unix domain networking properties that can be used to select the temporary directory where these sockets are created.
- Parameters:
local- The address to bind the socket, ornullto 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 occurs- Since:
- 1.7
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setOption
Description copied from interface:NetworkChannelSets the value of a socket option.- Specified by:
setOptionin interfaceNetworkChannel- Type Parameters:
T- The type of the socket option value- Parameters:
name- The socket optionvalue- The value of the socket option. A value ofnullmay 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:
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socket
Retrieves a server socket associated with this channel.The returned object will not declare any public methods that are not declared in the
ServerSocketclass.- Returns:
- A server socket associated with this channel
- Throws:
UnsupportedOperationException- If the channel's socket is not an Internet protocol socket
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accept
Accepts a connection made to this channel's socket.If this channel is in non-blocking mode then this method will immediately return
nullif 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.
- Returns:
- The socket channel for the new connection,
or
nullif 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 boundIOException- 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
boundto an Internet Protocol socket address then the return value from this method is of typeInetSocketAddress.Where the channel is bound to a Unix Domain socket address, the socket address is a
UnixDomainSocketAddress.- Specified by:
getLocalAddressin interfaceNetworkChannel- Returns:
- The
SocketAddressthat the socket is bound to ornullif the channel's socket is not bound - Throws:
ClosedChannelException- If the channel is closedIOException- If an I/O error occurs
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