SocketImpl (Java Platform SE 8 )

java.lang.Object
- java.net.SocketImpl

All Implemented Interfaces:

SocketOptions
```
public abstract class SocketImpl
extends Object
implements SocketOptions
```
The abstract class SocketImpl is a common superclass of all classes that actually implement sockets. It is used to create both client and server sockets.
A "plain" socket implements these methods exactly as described, without attempting to go through a firewall or proxy.

Since:

JDK1.0

Field Summary

Fields
Modifier and Type	Field and Description
`protected InetAddress`	`address` The IP address of the remote end of this socket.
`protected FileDescriptor`	`fd` The file descriptor object for this socket.
`protected int`	`localport` The local port number to which this socket is connected.
`protected int`	`port` The port number on the remote host to which this socket is connected.

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()

Constructors
Constructor and Description
`SocketImpl()`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`protected abstract void`	`accept(SocketImpl s)` Accepts a connection.
`protected abstract int`	`available()` Returns the number of bytes that can be read from this socket without blocking.
`protected abstract void`	`bind(InetAddress host, int port)` Binds this socket to the specified local IP address and port number.
`protected abstract void`	`close()` Closes this socket.
`protected abstract void`	`connect(InetAddress address, int port)` Connects this socket to the specified port number on the specified host.
`protected abstract void`	`connect(SocketAddress address, int timeout)` Connects this socket to the specified port number on the specified host.
`protected abstract void`	`connect(String host, int port)` Connects this socket to the specified port on the named host.
`protected abstract void`	`create(boolean stream)` Creates either a stream or a datagram socket.
`protected FileDescriptor`	`getFileDescriptor()` Returns the value of this socket's `fd` field.
`protected InetAddress`	`getInetAddress()` Returns the value of this socket's `address` field.
`protected abstract InputStream`	`getInputStream()` Returns an input stream for this socket.
`protected int`	`getLocalPort()` Returns the value of this socket's `localport` field.
`protected abstract OutputStream`	`getOutputStream()` Returns an output stream for this socket.
`protected int`	`getPort()` Returns the value of this socket's `port` field.
`protected abstract void`	`listen(int backlog)` Sets the maximum queue length for incoming connection indications (a request to connect) to the `count` argument.
`protected abstract void`	`sendUrgentData(int data)` Send one byte of urgent data on the socket.
`protected void`	`setPerformancePreferences(int connectionTime, int latency, int bandwidth)` Sets performance preferences for this socket.
`protected void`	`shutdownInput()` Places the input stream for this socket at "end of stream".
`protected void`	`shutdownOutput()` Disables the output stream for this socket.
`protected boolean`	`supportsUrgentData()` Returns whether or not this SocketImpl supports sending urgent data.
`String`	`toString()` Returns the address and port of this socket as a `String`.

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
  - fd
```
protected FileDescriptor fd
```
    The file descriptor object for this socket.
  - address
```
protected InetAddress address
```
    The IP address of the remote end of this socket.
  - port
```
protected int port
```
    The port number on the remote host to which this socket is connected.
  - localport
```
protected int localport
```
    The local port number to which this socket is connected.
- Constructor Detail
  - SocketImpl
```
public SocketImpl()
```
- Method Detail
  - create
```
protected abstract void create(boolean stream)
                        throws IOException
```
    Creates either a stream or a datagram socket.
    
    Parameters:
    
    stream - if true, create a stream socket; otherwise, create a datagram socket.
    
    Throws:
    
    IOException - if an I/O error occurs while creating the socket.
  - connect
```
protected abstract void connect(String host,
                                int port)
                         throws IOException
```
    Connects this socket to the specified port on the named host.
    
    Parameters:
    
    host - the name of the remote host.
    
    port - the port number.
    
    Throws:
    
    IOException - if an I/O error occurs when connecting to the remote host.
  - connect
```
protected abstract void connect(InetAddress address,
                                int port)
                         throws IOException
```
    Connects this socket to the specified port number on the specified host.
    
    Parameters:
    
    address - the IP address of the remote host.
    
    port - the port number.
    
    Throws:
    
    IOException - if an I/O error occurs when attempting a connection.
  - connect
```
protected abstract void connect(SocketAddress address,
                                int timeout)
                         throws IOException
```
    Connects this socket to the specified port number on the specified host. A timeout of zero is interpreted as an infinite timeout. The connection will then block until established or an error occurs.
    
    Parameters:
    
    address - the Socket address of the remote host.
    
    timeout - the timeout value, in milliseconds, or zero for no timeout.
    
    Throws:
    
    IOException - if an I/O error occurs when attempting a connection.
    
    Since:
    
    1.4
  - bind
```
protected abstract void bind(InetAddress host,
                             int port)
                      throws IOException
```
    Binds this socket to the specified local IP address and port number.
    
    Parameters:
    
    host - an IP address that belongs to a local interface.
    
    port - the port number.
    
    Throws:
    
    IOException - if an I/O error occurs when binding this socket.
  - listen
```
protected abstract void listen(int backlog)
                        throws IOException
```
    Sets the maximum queue length for incoming connection indications (a request to connect) to the count argument. If a connection indication arrives when the queue is full, the connection is refused.
    
    Parameters:
    
    backlog - the maximum length of the queue.
    
    Throws:
    
    IOException - if an I/O error occurs when creating the queue.
  - accept
```
protected abstract void accept(SocketImpl s)
                        throws IOException
```
    Accepts a connection.
    
    Parameters:
    
    s - the accepted connection.
    
    Throws:
    
    IOException - if an I/O error occurs when accepting the connection.
  - getInputStream
```
protected abstract InputStream getInputStream()
                                       throws IOException
```
    Returns an input stream for this socket.
    
    Returns:
    
    a stream for reading from this socket.
    
    Throws:
    
    IOException - if an I/O error occurs when creating the input stream.
  - getOutputStream
```
protected abstract OutputStream getOutputStream()
                                         throws IOException
```
    Returns an output stream for this socket.
    
    Returns:
    
    an output stream for writing to this socket.
    
    Throws:
    
    IOException - if an I/O error occurs when creating the output stream.
  - available
```
protected abstract int available()
                          throws IOException
```
    Returns the number of bytes that can be read from this socket without blocking.
    
    Returns:
    
    the number of bytes that can be read from this socket without blocking.
    
    Throws:
    
    IOException - if an I/O error occurs when determining the number of bytes available.
  - close
```
protected abstract void close()
                       throws IOException
```
    Closes this socket.
    
    Throws:
    
    IOException - if an I/O error occurs when closing this socket.
  - shutdownInput
```
protected void shutdownInput()
                      throws IOException
```
    Places the input stream for this socket at "end of stream". Any data sent to this socket is acknowledged and then silently discarded. If you read from a socket input stream after invoking this method on the socket, the stream's available method will return 0, and its read methods will return -1 (end of stream).
    
    Throws:
    
    IOException - if an I/O error occurs when shutting down this socket.
    
    Since:
    
    1.3
    
    See Also:
    
    Socket.shutdownOutput(), Socket.close(), Socket.setSoLinger(boolean, int)
  - shutdownOutput
```
protected void shutdownOutput()
                       throws IOException
```
    Disables the output stream for this socket. For a TCP socket, any previously written data will be sent followed by TCP's normal connection termination sequence. If you write to a socket output stream after invoking shutdownOutput() on the socket, the stream will throw an IOException.
    
    Throws:
    
    IOException - if an I/O error occurs when shutting down this socket.
    
    Since:
    
    1.3
    
    See Also:
    
    Socket.shutdownInput(), Socket.close(), Socket.setSoLinger(boolean, int)
  - getFileDescriptor
```
protected FileDescriptor getFileDescriptor()
```
    Returns the value of this socket's fd field.
    
    Returns:
    
    the value of this socket's fd field.
    
    See Also:
    
    fd
  - getInetAddress
```
protected InetAddress getInetAddress()
```
    Returns the value of this socket's address field.
    
    Returns:
    
    the value of this socket's address field.
    
    See Also:
    
    address
  - getPort
```
protected int getPort()
```
    Returns the value of this socket's port field.
    
    Returns:
    
    the value of this socket's port field.
    
    See Also:
    
    port
  - supportsUrgentData
```
protected boolean supportsUrgentData()
```
    Returns whether or not this SocketImpl supports sending urgent data. By default, false is returned unless the method is overridden in a sub-class
    
    Returns:
    
    true if urgent data supported
    
    Since:
    
    1.4
    
    See Also:
    
    address
  - sendUrgentData
```
protected abstract void sendUrgentData(int data)
                                throws IOException
```
    Send one byte of urgent data on the socket. The byte to be sent is the low eight bits of the parameter
    
    Parameters:
    
    data - The byte of data to send
    
    Throws:
    
    IOException - if there is an error sending the data.
    
    Since:
    
    1.4
  - getLocalPort
```
protected int getLocalPort()
```
    Returns the value of this socket's localport field.
    
    Returns:
    
    the value of this socket's localport field.
    
    See Also:
    
    localport
  - toString
```
public String toString()
```
    Returns the address and port of this socket as a String.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    a string representation of this socket.
  - setPerformancePreferences
```
protected void setPerformancePreferences(int connectionTime,
                                         int latency,
                                         int bandwidth)
```
    Sets performance preferences for this socket.
    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. Negative values represent a lower priority than positive values. 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). By default, this method does nothing, unless it is overridden in a a sub-class.
    
    Parameters:
    
    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

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Class SocketImpl

Field Summary

Fields inherited from interface java.net.SocketOptions

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.net.SocketOptions

Field Detail

fd

address

port

localport

Constructor Detail

SocketImpl

Method Detail

create

connect

connect

connect

bind

listen

accept

getInputStream

getOutputStream

available

close

shutdownInput

shutdownOutput

getFileDescriptor

getInetAddress

getPort

supportsUrgentData

sendUrgentData

getLocalPort

toString

setPerformancePreferences