java.net

Class SocketImpl

public abstract class SocketImpl extends Object implements SocketOptions

This abstract class serves as the parent class for socket implementations. The implementation class serves an intermediary to native routines that perform system specific socket operations.

A default implementation is provided by the system, but this can be changed via installing a SocketImplFactory (through a call to the static method Socket.setSocketImplFactory). A subclass of Socket can also pass in a SocketImpl to the Socket(SocketImpl) constructor to use an implementation different from the system default without installing a factory.

Field Summary
protected InetAddress	address The address of the remote end of the socket connection
protected FileDescriptor	fd A FileDescriptor object representing this socket connection.
protected int	localport The port number the socket is bound to locally
protected int	port The port number of the remote end of the socket connection

Constructor Summary
	SocketImpl() Default, no-argument constructor for use by subclasses.

Method Summary
protected abstract void	accept(SocketImpl s) Accepts a connection on this socket.
protected abstract int	available() Returns the number of bytes that the caller can read from this socket without blocking.
protected abstract void	bind(InetAddress host, int port) Binds to the specified port on the specified addr.
protected abstract void	close() Closes the socket.
protected abstract void	connect(String host, int port) Connects to the remote hostname and port specified as arguments.
protected abstract void	connect(InetAddress host, int port) Connects to the remote address and port specified as arguments.
protected abstract void	connect(SocketAddress address, int timeout) Connects to the socket to the host specified in address.
protected abstract void	create(boolean stream) Creates a new socket that is not bound to any local address/port and is not connected to any remote address/port.
protected FileDescriptor	getFileDescriptor() Returns the FileDescriptor objects for this socket.
protected InetAddress	getInetAddress() Returns the remote address this socket is connected to
protected abstract InputStream	getInputStream() Returns an `InputStream` object for reading from this socket.
protected int	getLocalPort() Returns the local port this socket is bound to
protected abstract OutputStream	getOutputStream() Returns an `OutputStream` object for writing to this socket
protected int	getPort() Returns the remote port this socket is connected to
protected abstract void	listen(int backlog) Starts listening for connections on a socket.
protected abstract void	sendUrgentData(int data) Sends one byte of urgent data to the socket.
protected void	shutdownInput() Shut down the input side of this socket.
protected void	shutdownOutput() Shut down the output side of this socket.
protected boolean	supportsUrgentData() Returns true or false when this socket supports sending urgent data or not.
String	toString() Returns a `String` representing the remote host and port of this socket.

Field Detail

address

protected InetAddress address

The address of the remote end of the socket connection

fd

protected FileDescriptor fd

A FileDescriptor object representing this socket connection.

localport

protected int localport

The port number the socket is bound to locally

port

protected int port

The port number of the remote end of the socket connection

Constructor Detail

SocketImpl

public SocketImpl()

Default, no-argument constructor for use by subclasses.

Method Detail

accept

protected abstract void accept(SocketImpl s)

Accepts a connection on this socket.

Parameters: s The implementation object for the accepted connection.

Throws: IOException If an error occurs

available

protected abstract int available()

Returns the number of bytes that the caller can read from this socket without blocking.

Returns: The number of readable bytes before blocking

Throws: IOException If an error occurs

bind

protected abstract void bind(InetAddress host, int port)

Binds to the specified port on the specified addr. Note that this addr must represent a local IP address.

Note that it is unspecified how to bind to all interfaces on the localhost (INADDR_ANY).

Parameters: host The address to bind to port The port number to bind to

Throws: IOException If an error occurs

close

protected abstract void close()

Closes the socket. This will normally cause any resources, such as the InputStream, OutputStream and associated file descriptors to be freed.

Note that if the SO_LINGER option is set on this socket, then the operation could block.

Throws: IOException If an error occurs

connect

protected abstract void connect(String host, int port)

Connects to the remote hostname and port specified as arguments.

Parameters: host The remote hostname to connect to port The remote port to connect to

Throws: IOException If an error occurs

connect

protected abstract void connect(InetAddress host, int port)

Connects to the remote address and port specified as arguments.

Parameters: host The remote address to connect to port The remote port to connect to

Throws: IOException If an error occurs

connect

protected abstract void connect(SocketAddress address, int timeout)

Connects to the socket to the host specified in address. This method blocks until successful connected or the timeout occurs. A timeout of zero means no timout.

Parameters: address Data of remote host timeout time to wait to stop connecting

Throws: IOException If an error occurs

Since: 1.4

create

protected abstract void create(boolean stream)

Creates a new socket that is not bound to any local address/port and is not connected to any remote address/port. This will be created as a stream socket if the stream parameter is true, or a datagram socket if the stream parameter is false.

Parameters: stream true for a stream socket, false for a datagram socket

Throws: IOException If an error occurs

getFileDescriptor

protected FileDescriptor getFileDescriptor()

Returns the FileDescriptor objects for this socket.

Returns: A FileDescriptor for this socket.

getInetAddress

protected InetAddress getInetAddress()

Returns the remote address this socket is connected to

Returns: The remote address

getInputStream

protected abstract InputStream getInputStream()

Returns an InputStream object for reading from this socket.

Returns: An InputStream for reading from this socket.

Throws: IOException If an error occurs

getLocalPort

protected int getLocalPort()

Returns the local port this socket is bound to

Returns: The local port

getOutputStream

protected abstract OutputStream getOutputStream()

Returns an OutputStream object for writing to this socket

Returns: An OutputStream for writing to this socket.

Throws: IOException If an error occurs.

getPort

protected int getPort()

Returns the remote port this socket is connected to

Returns: The remote port

listen

protected abstract void listen(int backlog)

Starts listening for connections on a socket. The backlog parameter is how many pending connections will queue up waiting to be serviced before being accept'ed. If the queue of pending requests exceeds this number, additional connections will be refused.

Parameters: backlog The length of the pending connection queue

Throws: IOException If an error occurs