SocketImpl
public
abstract
class
SocketImpl
extends Object
implements
SocketOptions
java.lang.Object | |
↳ | java.net.SocketImpl |
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.
Summary
Inherited constants |
---|
Fields | |
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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. |
Public constructors | |
---|---|
SocketImpl()
|
Public methods | |
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String
|
toString()
Returns the address and port of this socket as a |
Protected methods | |
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abstract
void
|
accept(SocketImpl s)
Accepts a connection. |
abstract
int
|
available()
Returns the number of bytes that can be read from this socket without blocking. |
abstract
void
|
bind(InetAddress host, int port)
Binds this socket to the specified local IP address and port number. |
abstract
void
|
close()
Closes this socket. |
abstract
void
|
connect(InetAddress address, int port)
Connects this socket to the specified port number on the specified host. |
abstract
void
|
connect(SocketAddress address, int timeout)
Connects this socket to the specified port number on the specified host. |
abstract
void
|
connect(String host, int port)
Connects this socket to the specified port on the named host. |
abstract
void
|
create(boolean stream)
Creates either a stream or a datagram socket. |
FileDescriptor
|
getFileDescriptor()
Returns the value of this socket's |
InetAddress
|
getInetAddress()
Returns the value of this socket's |
abstract
InputStream
|
getInputStream()
Returns an input stream for this socket. |
int
|
getLocalPort()
Returns the value of this socket's |
<T>
T
|
getOption(SocketOption<T> name)
Called to get a socket option. |
abstract
OutputStream
|
getOutputStream()
Returns an output stream for this socket. |
int
|
getPort()
Returns the value of this socket's |
abstract
void
|
listen(int backlog)
Sets the maximum queue length for incoming connection indications
(a request to connect) to the |
abstract
void
|
sendUrgentData(int data)
Send one byte of urgent data on the socket. |
<T>
void
|
setOption(SocketOption<T> name, T value)
Called to set a socket option. |
void
|
setPerformancePreferences(int connectionTime, int latency, int bandwidth)
Sets performance preferences for this socket. |
void
|
shutdownInput()
Places the input stream for this socket at "end of stream". |
void
|
shutdownOutput()
Disables the output stream for this socket. |
Set<SocketOption<?>>
|
supportedOptions()
Returns a set of SocketOptions supported by this impl and by this impl's socket (Socket or ServerSocket) |
boolean
|
supportsUrgentData()
Returns whether or not this SocketImpl supports sending urgent data. |
Inherited methods | |
---|---|
Fields
address
protected InetAddress address
The IP address of the remote end of this socket.
localport
protected int localport
The local port number to which this socket is connected.
port
protected int port
The port number on the remote host to which this socket is connected.
Public constructors
Public methods
toString
public String toString ()
Returns the address and port of this socket as a String
.
Returns | |
---|---|
String |
a string representation of this socket. |
Protected methods
accept
protected abstract void accept (SocketImpl s)
Accepts a connection.
Parameters | |
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s |
SocketImpl : the accepted connection. |
Throws | |
---|---|
IOException |
if an I/O error occurs when accepting the connection. |
available
protected abstract int available ()
Returns the number of bytes that can be read from this socket without blocking.
Returns | |
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int |
the number of bytes that can be read from this socket without blocking. |
Throws | |
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IOException |
if an I/O error occurs when determining the number of bytes available. |
bind
protected abstract void bind (InetAddress host, int port)
Binds this socket to the specified local IP address and port number.
Parameters | |
---|---|
host |
InetAddress : an IP address that belongs to a local interface. |
port |
int : the port number. |
Throws | |
---|---|
IOException |
if an I/O error occurs when binding this socket. |
close
protected abstract void close ()
Closes this socket.
Throws | |
---|---|
IOException |
if an I/O error occurs when closing this socket. |
connect
protected abstract void connect (InetAddress address, int port)
Connects this socket to the specified port number on the specified host.
Parameters | |
---|---|
address |
InetAddress : the IP address of the remote host. |
port |
int : the port number. |
Throws | |
---|---|
IOException |
if an I/O error occurs when attempting a connection. |
connect
protected abstract void connect (SocketAddress address, int timeout)
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 |
SocketAddress : the Socket address of the remote host. |
timeout |
int : the timeout value, in milliseconds, or zero for no timeout. |
Throws | |
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IOException |
if an I/O error occurs when attempting a connection. |
connect
protected abstract void connect (String host, int port)
Connects this socket to the specified port on the named host.
Parameters | |
---|---|
host |
String : the name of the remote host. |
port |
int : the port number. |
Throws | |
---|---|
IOException |
if an I/O error occurs when connecting to the remote host. |
create
protected abstract void create (boolean stream)
Creates either a stream or a datagram socket.
Parameters | |
---|---|
stream |
boolean : if true , create a stream socket;
otherwise, create a datagram socket. |
Throws | |
---|---|
IOException |
if an I/O error occurs while creating the socket. |
getFileDescriptor
protected FileDescriptor getFileDescriptor ()
Returns the value of this socket's fd
field.
Returns | |
---|---|
FileDescriptor |
the value of this socket's fd field. |
See also:
getInetAddress
protected InetAddress getInetAddress ()
Returns the value of this socket's address
field.
Returns | |
---|---|
InetAddress |
the value of this socket's address field. |
See also:
getInputStream
protected abstract InputStream getInputStream ()
Returns an input stream for this socket.
Returns | |
---|---|
InputStream |
a stream for reading from this socket. |
Throws | |
---|---|
IOException |
if an I/O error occurs when creating the input stream. |
getLocalPort
protected int getLocalPort ()
Returns the value of this socket's localport
field.
Returns | |
---|---|
int |
the value of this socket's localport field. |
See also:
getOption
protected T getOption (SocketOption<T> name)
Called to get a socket option.
Parameters | |
---|---|
name |
SocketOption : The socket option |
Returns | |
---|---|
T |
the value of the named option |
Throws | |
---|---|
UnsupportedOperationException |
if the SocketImpl does not support the option. |
IOException |
if an I/O error occurs, or if the socket is closed. |
getOutputStream
protected abstract OutputStream getOutputStream ()
Returns an output stream for this socket.
Returns | |
---|---|
OutputStream |
an output stream for writing to this socket. |
Throws | |
---|---|
IOException |
if an I/O error occurs when creating the output stream. |
getPort
protected int getPort ()
Returns the value of this socket's port
field.
Returns | |
---|---|
int |
the value of this socket's port field. |
See also:
listen
protected abstract void listen (int backlog)
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 |
int : the maximum length of the queue. |
Throws | |
---|---|
IOException |
if an I/O error occurs when creating the queue. |
sendUrgentData
protected abstract void sendUrgentData (int data)
Send one byte of urgent data on the socket. The byte to be sent is the low eight bits of the parameter
Parameters | |
---|---|
data |
int : The byte of data to send |
Throws | |
---|---|
IOException |
if there is an error sending the data. |
setOption
protected void setOption (SocketOption<T> name, T value)
Called to set a socket option.
Parameters | |
---|---|
name |
SocketOption : The socket option |
value |
T : The value of the socket option. A value of null
may be valid for some options. |
Throws | |
---|---|
UnsupportedOperationException |
if the SocketImpl does not support the option |
IOException |
if an I/O error occurs, or if the socket is closed. |
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 sub-class.
Parameters | |
---|---|
connectionTime |
int : An int expressing the relative importance of a short
connection time |
latency |
int : An int expressing the relative importance of low
latency |
bandwidth |
int : An int expressing the relative importance of high
bandwidth |
shutdownInput
protected void shutdownInput ()
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. |
shutdownOutput
protected void shutdownOutput ()
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. |
supportedOptions
protected Set<SocketOption<?>> supportedOptions ()
Returns a set of SocketOptions supported by this impl and by this impl's socket (Socket or ServerSocket)
Returns | |
---|---|
Set<SocketOption<?>> |
a Set of SocketOptions |
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 | |
---|---|
boolean |
true if urgent data supported |
See also: