Creates an unbound server socket.

Throws	IOException: IO error when opening the socket.
revised	1.4

Creates a server socket, bound to the specified port. A port of 0 creates a socket on any free port.

The maximum queue length for incoming connection indications (a request to connect) is set to 50. If a connection indication arrives when the queue is full, the connection is refused.

If the application has specified a server socket factory, that factory's createSocketImpl method is called to create the actual socket implementation. Otherwise a "plain" socket is created.

If there is a security manager, its checkListen method is called with the port argument as its argument to ensure the operation is allowed. This could result in a SecurityException.

port	the port number, or 0 to use any free port.
Throws	IOException: if an I/O error occurs when opening the socket.
Throws	SecurityException: if a security manager exists and its checkListen method doesn't allow the operation.
See also	java.net.SocketImpl, createSocketImpl(), setSocketFactory(java.net.SocketImplFactory), checkListen

Creates a server socket and binds it to the specified local port number, with the specified backlog. A port number of 0 creates a socket on any free port.

The maximum queue length for incoming connection indications (a request to connect) is set to the backlog parameter. If a connection indication arrives when the queue is full, the connection is refused.

If the application has specified a server socket factory, that factory's createSocketImpl method is called to create the actual socket implementation. Otherwise a "plain" socket is created.

If there is a security manager, its checkListen method is called with the port argument as its argument to ensure the operation is allowed. This could result in a SecurityException.

The backlog argument must be a positive value greater than 0. If the value passed if equal or less than 0, then the default value will be assumed.

port	the specified port, or 0 to use any free port.
backlog	the maximum length of the queue.
Throws	IOException: if an I/O error occurs when opening the socket.
Throws	SecurityException: if a security manager exists and its checkListen method doesn't allow the operation.
See also	java.net.SocketImpl, createSocketImpl(), setSocketFactory(java.net.SocketImplFactory), checkListen

Create a server with the specified port, listen backlog, and local IP address to bind to. The bindAddr argument can be used on a multi-homed host for a ServerSocket that will only accept connect requests to one of its addresses. If bindAddr is null, it will default accepting connections on any/all local addresses. The port must be between 0 and 65535, inclusive.

If there is a security manager, this method calls its checkListen method with the port argument as its argument to ensure the operation is allowed. This could result in a SecurityException.

The backlog argument must be a positive value greater than 0. If the value passed if equal or less than 0, then the default value will be assumed.

port	the local TCP port
backlog	the listen backlog
bindAddr	the local InetAddress the server will bind to
Throws	SecurityException: if a security manager exists and its checkListen method doesn't allow the operation.
Throws	IOException: if an I/O error occurs when opening the socket.
since	JDK1.1
See also	java.net.SocketOptions, java.net.SocketImpl, checkListen

Listens for a connection to be made to this socket and accepts it. The method blocks until a connection is made.

A new Socket s is created and, if there is a security manager, the security manager's checkAccept method is called with s.getInetAddress().getHostAddress() and s.getPort() as its arguments to ensure the operation is allowed. This could result in a SecurityException.

Throws	IOException: if an I/O error occurs when waiting for a connection.
Throws	SecurityException: if a security manager exists and its checkAccept method doesn't allow the operation.
Throws	SocketTimeoutException: if a timeout was previously set with setSoTimeout and the timeout has been reached.
Throws	java.nio.channels.IllegalBlockingModeException: if this socket has an associated channel, the channel is in non-blocking mode, and there is no connection ready to be accepted
return	the new Socket
revised	1.4
spec	JSR-51
See also	checkAccept

Binds the ServerSocket to a specific address (IP address and port number).

If the address is null, then the system will pick up an ephemeral port and a valid local address to bind the socket.

endpoint	The IP address & port number to bind to.
Throws	IOException: if the bind operation fails, or if the socket is already bound.
Throws	SecurityException: if a SecurityManager is present and its checkListen method doesn't allow the operation.
Throws	IllegalArgumentException: if endpoint is a SocketAddress subclass not supported by this socket
since	1.4

Binds the ServerSocket to a specific address (IP address and port number).

If the address is null, then the system will pick up an ephemeral port and a valid local address to bind the socket.

The backlog argument must be a positive value greater than 0. If the value passed if equal or less than 0, then the default value will be assumed.

endpoint	The IP address & port number to bind to.
backlog	The listen backlog length.
Throws	IOException: if the bind operation fails, or if the socket is already bound.
Throws	SecurityException: if a SecurityManager is present and its checkListen method doesn't allow the operation.
Throws	IllegalArgumentException: if endpoint is a SocketAddress subclass not supported by this socket
since	1.4

Closes this socket. Any thread currently blocked in #accept() will throw a SocketException.

If this socket has an associated channel then the channel is closed as well.

Throws	IOException: if an I/O error occurs when closing the socket.
revised	1.4
spec	JSR-51

Subclasses of ServerSocket use this method to override accept() to return their own subclass of socket. So a FooServerSocket will typically hand this method an empty FooSocket. On return from implAccept the FooSocket will be connected to a client.

s	the Socket
Throws	java.nio.channels.IllegalBlockingModeException: if this socket has an associated channel, and the channel is in non-blocking mode
Throws	IOException: if an I/O error occurs when waiting for a connection.
since	JDK1.1
revised	1.4
spec	JSR-51

Returns the implementation address and implementation port of this socket as a String.

return

a string representation of this socket.

Returns the binding state of the ServerSocket.

return	true if the ServerSocket succesfuly bound to an address
since	1.4

Returns the unique java.nio.channels.ServerSocketChannel object associated with this socket, if any.

A server socket will have a channel if, and only if, the channel itself was created via the ServerSocketChannel.open method.

return	the server-socket channel associated with this socket, or null if this socket was not created for a channel
since	1.4
spec	JSR-51

Returns the closed state of the ServerSocket.

return	true if the socket has been closed
since	1.4

Returns the local address of this server socket.

return

the address to which this socket is bound, or null if the socket is unbound.

Returns the port on which this socket is listening.

return

the port number to which this socket is listening or -1 if the socket is not bound yet.

Returns the address of the endpoint this socket is bound to, or null if it is not bound yet.

return	a SocketAddress representing the local endpoint of this socket, or null if it is not bound yet.
since	1.4
See also	getInetAddress(), getLocalPort(), bind(SocketAddress)

Sets performance preferences for this ServerSocket.

Sockets use the TCP/IP protocol by default. Some implementations may offer alternative protocols which have different performance characteristics than TCP/IP. This method allows the application to express its own preferences as to how these tradeoffs should be made when the implementation chooses from the available protocols.

Performance preferences are described by three integers whose values indicate the relative importance of short connection time, low latency, and high bandwidth. The absolute values of the integers are irrelevant; in order to choose a protocol the values are simply compared, with larger values indicating stronger preferences. If the application prefers short connection time over both low latency and high bandwidth, for example, then it could invoke this method with the values (1, 0, 0). If the application prefers high bandwidth above low latency, and low latency above short connection time, then it could invoke this method with the values (0, 1, 2).

Invoking this method after this socket has been bound will have no effect. This implies that in order to use this capability requires the socket to be created with the no-argument constructor.

connectionTime	An int expressing the relative importance of a short connection time
latency	An int expressing the relative importance of low latency
bandwidth	An int expressing the relative importance of high bandwidth
since	1.5

Sets a default proposed value for the SO_RCVBUF option for sockets accepted from this ServerSocket. The value actually set in the accepted socket must be determined by calling Socket#getReceiveBufferSize() after the socket is returned by #accept().

The value of SO_RCVBUF is used both to set the size of the internal socket receive buffer, and to set the size of the TCP receive window that is advertized to the remote peer.

It is possible to change the value subsequently, by calling Socket#setReceiveBufferSize(int). However, if the application wishes to allow a receive window larger than 64K bytes, as defined by RFC1323 then the proposed value must be set in the ServerSocket before it is bound to a local address. This implies, that the ServerSocket must be created with the no-argument constructor, then setReceiveBufferSize() must be called and lastly the ServerSocket is bound to an address by calling bind().

Failure to do this will not cause an error, and the buffer size may be set to the requested value but the TCP receive window in sockets accepted from this ServerSocket will be no larger than 64K bytes.

Throws	SocketException: if there is an error in the underlying protocol, such as a TCP error.
size	the size to which to set the receive buffer size. This value must be greater than 0.
Throws	IllegalArgumentException: if the value is 0 or is negative.
since	1.4
See also	getReceiveBufferSize

Gets the value of the SO_RCVBUF option for this ServerSocket, that is the proposed buffer size that will be used for Sockets accepted from this ServerSocket.

Note, the value actually set in the accepted socket is determined by calling Socket#getReceiveBufferSize().

return	the value of the SO_RCVBUF option for this Socket.
Throws	SocketException: if there is an error in the underlying protocol, such as a TCP error.
since	1.4
See also	setReceiveBufferSize(int)

Enable/disable the SO_REUSEADDR socket option.

When a TCP connection is closed the connection may remain in a timeout state for a period of time after the connection is closed (typically known as the TIME_WAIT state or 2MSL wait state). For applications using a well known socket address or port it may not be possible to bind a socket to the required SocketAddress if there is a connection in the timeout state involving the socket address or port.

Enabling SO_REUSEADDR prior to binding the socket using #bind(SocketAddress) allows the socket to be bound even though a previous connection is in a timeout state.

When a ServerSocket is created the initial setting of SO_REUSEADDR is not defined. Applications can use #getReuseAddress() to determine the initial setting of SO_REUSEADDR.

The behaviour when SO_REUSEADDR is enabled or disabled after a socket is bound (See #isBound()) is not defined.

on	whether to enable or disable the socket option
Throws	SocketException: if an error occurs enabling or disabling the SO_RESUEADDR socket option, or the socket is closed.
since	1.4
See also	getReuseAddress(), bind(SocketAddress), isBound(), isClosed()

Tests if SO_REUSEADDR is enabled.

return	a boolean indicating whether or not SO_REUSEADDR is enabled.
Throws	SocketException: if there is an error in the underlying protocol, such as a TCP error.
since	1.4
See also	setReuseAddress(boolean)

Sets the server socket implementation factory for the application. The factory can be specified only once.

When an application creates a new server socket, the socket implementation factory's createSocketImpl method is called to create the actual socket implementation.

Passing null to the method is a no-op unless the factory was already set.

If there is a security manager, this method first calls the security manager's checkSetFactory method to ensure the operation is allowed. This could result in a SecurityException.

fac	the desired factory.
Throws	IOException: if an I/O error occurs when setting the socket factory.
Throws	SocketException: if the factory has already been defined.
Throws	SecurityException: if a security manager exists and its checkSetFactory method doesn't allow the operation.
See also	createSocketImpl(), checkSetFactory

Enable/disable SO_TIMEOUT with the specified timeout, in milliseconds. With this option set to a non-zero timeout, a call to accept() for this ServerSocket will block for only this amount of time. If the timeout expires, a java.net.SocketTimeoutException is raised, though the ServerSocket is still valid. The option must be enabled prior to entering the blocking operation to have effect. The timeout must be > 0. A timeout of zero is interpreted as an infinite timeout.

timeout	the specified timeout, in milliseconds
Throws	SocketException: if there is an error in the underlying protocol, such as a TCP error.
since	JDK1.1
See also	getSoTimeout()

Retrieve setting for SO_TIMEOUT. 0 returns implies that the option is disabled (i.e., timeout of infinity).

return	the SO_TIMEOUT value
Throws	IOException: if an I/O error occurs
since	JDK1.1
See also	setSoTimeout(int)