java.net
Class SocketImpl

java.lang.Object
  extended by 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
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
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(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