- java.lang.Object
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- java.net.SocketImpl
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- All Implemented Interfaces:
SocketOptions
public abstract class SocketImpl extends Object implements SocketOptions
The abstract classSocketImplis 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:
- 1.0
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Field Summary
Fields Modifier and Type Field Description protected InetAddressaddressThe IP address of the remote end of this socket.protected FileDescriptorfdThe file descriptor object for this socket.protected intlocalportThe local port number to which this socket is connected.protected intportThe port number on the remote host to which this socket is connected.-
Fields declared in 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_REUSEPORT, SO_SNDBUF, SO_TIMEOUT, TCP_NODELAY
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Constructor Summary
Constructors Constructor Description SocketImpl()
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected abstract voidaccept(SocketImpl s)Accepts a connection.protected abstract intavailable()Returns the number of bytes that can be read from this socket without blocking.protected abstract voidbind(InetAddress host, int port)Binds this socket to the specified local IP address and port number.protected abstract voidclose()Closes this socket.protected abstract voidconnect(String host, int port)Connects this socket to the specified port on the named host.protected abstract voidconnect(InetAddress address, int port)Connects this socket to the specified port number on the specified host.protected abstract voidconnect(SocketAddress address, int timeout)Connects this socket to the specified port number on the specified host.protected abstract voidcreate(boolean stream)Creates either a stream or a datagram socket.protected FileDescriptorgetFileDescriptor()Returns the value of this socket'sfdfield.protected InetAddressgetInetAddress()Returns the value of this socket'saddressfield.protected abstract InputStreamgetInputStream()Returns an input stream for this socket.protected intgetLocalPort()Returns the value of this socket'slocalportfield.protected <T> TgetOption(SocketOption<T> name)Called to get a socket option.protected abstract OutputStreamgetOutputStream()Returns an output stream for this socket.protected intgetPort()Returns the value of this socket'sportfield.protected abstract voidlisten(int backlog)Sets the maximum queue length for incoming connection indications (a request to connect) to thecountargument.protected abstract voidsendUrgentData(int data)Send one byte of urgent data on the socket.protected <T> voidsetOption(SocketOption<T> name, T value)Called to set a socket option.protected voidsetPerformancePreferences(int connectionTime, int latency, int bandwidth)Sets performance preferences for this socket.protected voidshutdownInput()Places the input stream for this socket at "end of stream".protected voidshutdownOutput()Disables the output stream for this socket.protected Set<SocketOption<?>>supportedOptions()Returns a set of SocketOptions supported by this impl and by this impl's socket (Socket or ServerSocket)protected booleansupportsUrgentData()Returns whether or not this SocketImpl supports sending urgent data.StringtoString()Returns the address and port of this socket as aString.-
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods declared in interface java.net.SocketOptions
getOption, setOption
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Field Detail
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fd
protected FileDescriptor fd
The file descriptor object for this socket.
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address
protected InetAddress address
The IP address of the remote end of this socket.
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port
protected int port
The port number on the remote host to which this socket is connected.
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localport
protected int localport
The local port number to which this socket is connected.
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Method Detail
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create
protected abstract void create(boolean stream) throws IOExceptionCreates either a stream or a datagram socket.- Parameters:
stream- iftrue, create a stream socket; otherwise, create a datagram socket.- Throws:
IOException- if an I/O error occurs while creating the socket.
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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.
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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.
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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
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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.
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listen
protected abstract void listen(int backlog) throws IOExceptionSets the maximum queue length for incoming connection indications (a request to connect) to thecountargument. 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.
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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.
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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.
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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.
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available
protected abstract int available() throws IOExceptionReturns 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.
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close
protected abstract void close() throws IOExceptionCloses this socket.- Throws:
IOException- if an I/O error occurs when closing this socket.
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shutdownInput
protected void shutdownInput() throws IOExceptionPlaces 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'savailablemethod will return 0, and itsreadmethods 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)
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shutdownOutput
protected void shutdownOutput() throws IOExceptionDisables 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)
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getFileDescriptor
protected FileDescriptor getFileDescriptor()
Returns the value of this socket'sfdfield.- Returns:
- the value of this socket's
fdfield. - See Also:
fd
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getInetAddress
protected InetAddress getInetAddress()
Returns the value of this socket'saddressfield.- Returns:
- the value of this socket's
addressfield. - See Also:
address
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getPort
protected int getPort()
Returns the value of this socket'sportfield.- Returns:
- the value of this socket's
portfield. - See Also:
port
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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
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sendUrgentData
protected abstract void sendUrgentData(int data) throws IOExceptionSend 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
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getLocalPort
protected int getLocalPort()
Returns the value of this socket'slocalportfield.- Returns:
- the value of this socket's
localportfield. - See Also:
localport
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toString
public String toString()
Returns the address and port of this socket as aString.
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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- Anintexpressing the relative importance of a short connection timelatency- Anintexpressing the relative importance of low latencybandwidth- Anintexpressing the relative importance of high bandwidth- Since:
- 1.5
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setOption
protected <T> void setOption(SocketOption<T> name, T value) throws IOException
Called to set a socket option.- Type Parameters:
T- The type of the socket option value- Parameters:
name- The socket optionvalue- The value of the socket option. A value ofnullmay be valid for some options.- Throws:
UnsupportedOperationException- if the SocketImpl does not support the optionIOException- if an I/O error occurs, or if the socket is closed.- Since:
- 9
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getOption
protected <T> T getOption(SocketOption<T> name) throws IOException
Called to get a socket option.- Type Parameters:
T- The type of the socket option value- Parameters:
name- The socket option- Returns:
- 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.- Since:
- 9
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supportedOptions
protected Set<SocketOption<?>> supportedOptions()
Returns a set of SocketOptions supported by this impl and by this impl's socket (Socket or ServerSocket)- Returns:
- a Set of SocketOptions
- Since:
- 9
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