java.net

Class SocketImpl

java.lang.Object

java.net.SocketImpl

All Implemented Interfaces:

SocketOptions

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

Fields

Modifier and Type	Field and Description
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

Fields inherited from interface java.net.SocketOptions

IP_MULTICAST_IF, IP_MULTICAST_IF2, IP_MULTICAST_LOOP, IP_TOS, SO_BINDADDR, SO_BROADCAST, SO_KEEPALIVE, SO_LINGER, SO_OOBINLINE, SO_RCVBUF, SO_REUSEADDR, SO_SNDBUF, SO_TIMEOUT, TCP_NODELAY

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
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(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	connect(String host, int port) Connects to the remote hostname and port specified as arguments.
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.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.net.SocketOptions

getOption, setOption

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

create

protected abstract void create(boolean stream)
                        throws IOException

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

connect

protected abstract void connect(String host,
           int port)
                         throws IOException

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)
                         throws IOException

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)
                         throws IOException

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

bind

protected abstract void bind(InetAddress host,
        int port)
                      throws IOException

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

listen

protected abstract void listen(int backlog)
                        throws IOException

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

accept

protected abstract void accept(SocketImpl s)
                        throws IOException

Accepts a connection on this socket.

Parameters:

s - The implementation object for the accepted connection.

Throws:

IOException - If an error occurs

getInputStream

protected abstract InputStream getInputStream()
                                       throws IOException

Returns an InputStream object for reading from this socket.

Returns:

An InputStream for reading from this socket.

Throws:

IOException - If an error occurs

getOutputStream

protected abstract OutputStream getOutputStream()
                                         throws IOException

Returns an OutputStream object for writing to this socket

Returns:

An OutputStream for writing to this socket.

Throws:

IOException - If an error occurs.

available

protected abstract int available()
                          throws IOException

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

close

protected abstract void close()
                       throws IOException

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

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

getPort

protected int getPort()

Returns the remote port this socket is connected to

Returns:

The remote port

supportsUrgentData

protected boolean supportsUrgentData()

Returns true or false when this socket supports sending urgent data or not.

Returns:

true if the socket implementation supports sending urgent data, false otherwise

Since:

1.4

sendUrgentData

protected abstract void sendUrgentData(int data)
                                throws IOException

Sends one byte of urgent data to the socket.

Parameters:

data - The byte to send, the low eight bits of it

Throws:

IOException - If an error occurs

Since:

1.4

getLocalPort

protected int getLocalPort()

Returns the local port this socket is bound to

Returns:

The local port

toString

public String toString()

Returns a String representing the remote host and port of this socket.

Overrides:

toString in class Object

Returns:

A String for this socket.

See Also:

Object.getClass(), Object.hashCode(), Class.getName(), Integer.toHexString(int)

shutdownInput

protected void shutdownInput()
                      throws IOException

Shut down the input side of this socket. Subsequent reads will return end-of-file.

Throws:

IOException - if an error occurs

shutdownOutput

protected void shutdownOutput()
                       throws IOException

Shut down the output side of this socket. Subsequent writes will fail with an IOException.

Throws:

IOException - if an error occurs