public class

ServerSocketAdaptor

extends ServerSocket
java.lang.Object
   ↳ java.net.ServerSocket
     ↳ sun.nio.ch.ServerSocketAdaptor

Summary

Public Methods
Socket accept()
Listens for a connection to be made to this socket and accepts it.
void bind(SocketAddress local)
Binds the ServerSocket to a specific address (IP address and port number).
void bind(SocketAddress local, int backlog)
Binds the ServerSocket to a specific address (IP address and port number).
void close()
Closes this socket.
static ServerSocket create(ServerSocketChannelImpl ssc)
ServerSocketChannel getChannel()
Returns the unique ServerSocketChannel object associated with this socket, if any.
InetAddress getInetAddress()
Returns the local address of this server socket.
int getLocalPort()
Returns the port number on which this socket is listening.
int 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.
boolean getReuseAddress()
Tests if SO_REUSEADDR is enabled.
int getSoTimeout()
Retrieve setting for SO_TIMEOUT.
boolean isBound()
Returns the binding state of the ServerSocket.
boolean isClosed()
Returns the closed state of the ServerSocket.
void setReceiveBufferSize(int size)
Sets a default proposed value for the SO_RCVBUF option for sockets accepted from this ServerSocket.
void setReuseAddress(boolean on)
Enable/disable the SO_REUSEADDR socket option.
void setSoTimeout(int timeout)
Enable/disable SO_TIMEOUT with the specified timeout, in milliseconds.
String toString()
Returns the implementation address and implementation port of this socket as a String.
[Expand]
Inherited Methods
From class java.net.ServerSocket
From class java.lang.Object

Public Methods

public Socket accept ()

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.

Returns
  • the new Socket
Throws
IOException

public void bind (SocketAddress local)

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.

Parameters
local The IP address & port number to bind to.
Throws
IOException

public void bind (SocketAddress local, int backlog)

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 is equal or less than 0, then the default value will be assumed.

Parameters
local The IP address & port number to bind to.
backlog The listen backlog length.
Throws
IOException

public void close ()

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

public static ServerSocket create (ServerSocketChannelImpl ssc)

public ServerSocketChannel getChannel ()

Returns the unique 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.

Returns
  • the server-socket channel associated with this socket, or null if this socket was not created for a channel

public InetAddress getInetAddress ()

Returns the local address of this server socket.

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

public int getLocalPort ()

Returns the port number on which this socket is listening.

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

public int 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 getReceiveBufferSize().

Returns
  • the value of the SO_RCVBUF option for this Socket.

public boolean getReuseAddress ()

Tests if SO_REUSEADDR is enabled.

Returns
  • a boolean indicating whether or not SO_REUSEADDR is enabled.

public int getSoTimeout ()

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

Returns
  • the SO_TIMEOUT value

public boolean isBound ()

Returns the binding state of the ServerSocket.

Returns
  • true if the ServerSocket succesfuly bound to an address

public boolean isClosed ()

Returns the closed state of the ServerSocket.

Returns
  • true if the socket has been closed

public void setReceiveBufferSize (int size)

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 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 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.

Parameters
size the size to which to set the receive buffer size. This value must be greater than 0.

public void setReuseAddress (boolean on)

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.

Parameters
on whether to enable or disable the socket option

public void setSoTimeout (int timeout)

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.

Parameters
timeout the specified timeout, in milliseconds

public String toString ()

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

Returns
  • a string representation of this socket.