Known Direct Subclasses |
This class implements client sockets (also called just "sockets"). A socket is an endpoint for communication between two machines.
The actual work of the socket is performed by an instance of the
SocketImpl
class. An application, by changing
the socket factory that creates the socket implementation,
can configure itself to create sockets appropriate to the local
firewall.
Public Constructor Summary
Socket()
Creates an unconnected socket, with the
system-default type of SocketImpl.
|
|
Socket(InetAddress address, int port)
Creates a stream socket and connects it to the specified port
number at the specified IP address.
|
|
Socket(String host, int port, InetAddress localAddr, int localPort)
Creates a socket and connects it to the specified remote host on
the specified remote port.
|
|
Socket(InetAddress address, int port, InetAddress localAddr, int localPort)
Creates a socket and connects it to the specified remote address on
the specified remote port.
|
|
Socket(InetAddress host, int port, boolean stream)
This constructor is deprecated.
Use DatagramSocket instead for UDP transport.
|
Protected Constructor Summary
Public Method Summary
void | |
synchronized void |
close()
Closes this socket.
|
void |
connect(SocketAddress endpoint, int timeout)
Connects this socket to the server with a specified timeout value.
|
void | |
SocketChannel |
getChannel()
Returns the unique
SocketChannel
object associated with this socket, if any. |
InetAddress |
getInetAddress()
Returns the address to which the socket is connected.
|
InputStream |
getInputStream()
Returns an input stream for this socket.
|
boolean |
getKeepAlive()
Tests if
SO_KEEPALIVE is enabled. |
InetAddress |
getLocalAddress()
Gets the local address to which the socket is bound.
|
int |
getLocalPort()
Returns the local port number to which this socket is bound.
|
SocketAddress |
getLocalSocketAddress()
Returns the address of the endpoint this socket is bound to.
|
boolean |
getOOBInline()
Tests if
SO_OOBINLINE is enabled. |
OutputStream |
getOutputStream()
Returns an output stream for this socket.
|
int |
getPort()
Returns the remote port number to which this socket is connected.
|
synchronized int |
getReceiveBufferSize()
Gets the value of the
SO_RCVBUF option
for this Socket , that is the buffer size used by the platform
for input on this Socket . |
SocketAddress |
getRemoteSocketAddress()
Returns the address of the endpoint this socket is connected to, or
null if it is unconnected. |
boolean |
getReuseAddress()
Tests if
SO_REUSEADDR is enabled. |
synchronized int |
getSendBufferSize()
Get value of the
SO_SNDBUF option
for this Socket , that is the buffer size used by the platform
for output on this Socket . |
int |
getSoLinger()
Returns setting for
SO_LINGER . |
synchronized int |
getSoTimeout()
Returns setting for
SO_TIMEOUT . |
boolean |
getTcpNoDelay()
Tests if
TCP_NODELAY is enabled. |
int |
getTrafficClass()
Gets traffic class or type-of-service in the IP header
for packets sent from this Socket
As the underlying network implementation may ignore the
traffic class or type-of-service set using |
boolean |
isBound()
Returns the binding state of the socket.
|
boolean |
isClosed()
Returns the closed state of the socket.
|
boolean |
isConnected()
Returns the connection state of the socket.
|
boolean |
isInputShutdown()
Returns whether the read-half of the socket connection is closed.
|
boolean |
isOutputShutdown()
Returns whether the write-half of the socket connection is closed.
|
void |
sendUrgentData(int data)
Send one byte of urgent data on the socket.
|
void |
setKeepAlive(boolean on)
Enable/disable
SO_KEEPALIVE . |
void |
setOOBInline(boolean on)
Enable/disable
SO_OOBINLINE
(receipt of TCP urgent data)
By default, this option is disabled and TCP urgent data received on a
socket is silently discarded. |
void |
setPerformancePreferences(int connectionTime, int latency, int bandwidth)
Sets performance preferences for this socket.
|
synchronized void |
setReceiveBufferSize(int size)
Sets the
SO_RCVBUF option to the
specified value for this Socket . |
void |
setReuseAddress(boolean on)
Enable/disable the
SO_REUSEADDR
socket option. |
synchronized void |
setSendBufferSize(int size)
Sets the
SO_SNDBUF option to the
specified value for this Socket . |
void |
setSoLinger(boolean on, int linger)
Enable/disable
SO_LINGER with the
specified linger time in seconds. |
synchronized void |
setSoTimeout(int timeout)
Enable/disable
SO_TIMEOUT
with the specified timeout, in milliseconds. |
synchronized static void |
setSocketImplFactory(SocketImplFactory fac)
Sets the client socket implementation factory for the
application.
|
void |
setTcpNoDelay(boolean on)
Enable/disable
TCP_NODELAY
(disable/enable Nagle's algorithm). |
void |
setTrafficClass(int tc)
Sets traffic class or type-of-service octet in the IP
header for packets sent from this Socket.
|
void |
shutdownInput()
Places the input stream for this socket at "end of stream".
|
void |
shutdownOutput()
Disables the output stream for this socket.
|
String |
toString()
Converts this socket to a
String . |
Inherited Method Summary
Public Constructors
public Socket ()
Creates an unconnected socket, with the system-default type of SocketImpl.
public Socket (Proxy proxy)
Creates an unconnected socket, specifying the type of proxy, if any, that should be used regardless of any other settings.
If there is a security manager, its checkConnect
method
is called with the proxy host address and port number
as its arguments. This could result in a SecurityException.
Examples:
Socket s = new Socket(Proxy.NO_PROXY);
will create a plain socket ignoring any other proxy configuration.Socket s = new Socket(new Proxy(Proxy.Type.SOCKS, new InetSocketAddress("socks.mydom.com", 1080)));
will create a socket connecting through the specified SOCKS proxy server.
Parameters
proxy | a Proxy object specifying what kind
of proxying should be used. |
---|
Throws
IllegalArgumentException | if the proxy is of an invalid type
or null . |
---|---|
SecurityException | if a security manager is present and permission to connect to the proxy is denied. |
See Also
public Socket (String host, int port)
Creates a stream socket and connects it to the specified port number on the named host.
If the specified host is null
it is the equivalent of
specifying the address as
InetAddress.getByName
(null)
.
In other words, it is equivalent to specifying an address of the
loopback interface.
If the application has specified a server socket factory, that
factory's createSocketImpl
method is called to create
the actual socket implementation. Otherwise a "plain" socket is created.
If there is a security manager, its
checkConnect
method is called
with the host address and port
as its arguments. This could result in a SecurityException.
Parameters
host | the host name, or null for the loopback address. |
---|---|
port | the port number. |
Throws
UnknownHostException | if the IP address of the host could not be determined. |
---|---|
IOException | if an I/O error occurs when creating the socket. |
SecurityException | if a security manager exists and its
checkConnect method doesn't allow the operation. |
IllegalArgumentException | if the port parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive. |
public Socket (InetAddress address, int port)
Creates a stream socket and connects it to the specified port number at the specified IP address.
If the application has specified a socket factory, that factory's
createSocketImpl
method is called to create the
actual socket implementation. Otherwise a "plain" socket is created.
If there is a security manager, its
checkConnect
method is called
with the host address and port
as its arguments. This could result in a SecurityException.
Parameters
address | the IP address. |
---|---|
port | the port number. |
Throws
IOException | if an I/O error occurs when creating the socket. |
---|---|
SecurityException | if a security manager exists and its
checkConnect method doesn't allow the operation. |
IllegalArgumentException | if the port parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive. |
NullPointerException | if address is null. |
public Socket (String host, int port, InetAddress localAddr, int localPort)
Creates a socket and connects it to the specified remote host on the specified remote port. The Socket will also bind() to the local address and port supplied.
If the specified host is null
it is the equivalent of
specifying the address as
InetAddress.getByName
(null)
.
In other words, it is equivalent to specifying an address of the
loopback interface.
A local port number of zero
will let the system pick up a
free port in the bind
operation.
If there is a security manager, its
checkConnect
method is called
with the host address and port
as its arguments. This could result in a SecurityException.
Parameters
host | the name of the remote host, or null for the loopback address. |
---|---|
port | the remote port |
localAddr | the local address the socket is bound to, or
null for the anyLocal address. |
localPort | the local port the socket is bound to, or
zero for a system selected free port. |
Throws
IOException | if an I/O error occurs when creating the socket. |
---|---|
SecurityException | if a security manager exists and its
checkConnect method doesn't allow the connection
to the destination, or if its checkListen method
doesn't allow the bind to the local port. |
IllegalArgumentException | if the port parameter or localPort parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive. |
public Socket (InetAddress address, int port, InetAddress localAddr, int localPort)
Creates a socket and connects it to the specified remote address on the specified remote port. The Socket will also bind() to the local address and port supplied.
If the specified local address is null
it is the equivalent of
specifying the address as the AnyLocal address
(see InetAddress.isAnyLocalAddress
()
).
A local port number of zero
will let the system pick up a
free port in the bind
operation.
If there is a security manager, its
checkConnect
method is called
with the host address and port
as its arguments. This could result in a SecurityException.
Parameters
address | the remote address |
---|---|
port | the remote port |
localAddr | the local address the socket is bound to, or
null for the anyLocal address. |
localPort | the local port the socket is bound to or
zero for a system selected free port. |
Throws
IOException | if an I/O error occurs when creating the socket. |
---|---|
SecurityException | if a security manager exists and its
checkConnect method doesn't allow the connection
to the destination, or if its checkListen method
doesn't allow the bind to the local port. |
IllegalArgumentException | if the port parameter or localPort parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive. |
NullPointerException | if address is null. |
public Socket (String host, int port, boolean stream)
This constructor is deprecated.
Use DatagramSocket instead for UDP transport.
Creates a stream socket and connects it to the specified port number on the named host.
If the specified host is null
it is the equivalent of
specifying the address as
InetAddress.getByName
(null)
.
In other words, it is equivalent to specifying an address of the
loopback interface.
If the stream argument is true
, this creates a
stream socket. If the stream argument is false
, it
creates a datagram socket.
If the application has specified a server socket factory, that
factory's createSocketImpl
method is called to create
the actual socket implementation. Otherwise a "plain" socket is created.
If there is a security manager, its
checkConnect
method is called
with the host address and port
as its arguments. This could result in a SecurityException.
If a UDP socket is used, TCP/IP related socket options will not apply.
Parameters
host | the host name, or null for the loopback address. |
---|---|
port | the port number. |
stream | a boolean indicating whether this is
a stream socket or a datagram socket. |
Throws
IOException | if an I/O error occurs when creating the socket. |
---|---|
SecurityException | if a security manager exists and its
checkConnect method doesn't allow the operation. |
IllegalArgumentException | if the port parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive. |
public Socket (InetAddress host, int port, boolean stream)
This constructor is deprecated.
Use DatagramSocket instead for UDP transport.
Creates a socket and connects it to the specified port number at the specified IP address.
If the stream argument is true
, this creates a
stream socket. If the stream argument is false
, it
creates a datagram socket.
If the application has specified a server socket factory, that
factory's createSocketImpl
method is called to create
the actual socket implementation. Otherwise a "plain" socket is created.
If there is a security manager, its
checkConnect
method is called
with host.getHostAddress()
and port
as its arguments. This could result in a SecurityException.
If UDP socket is used, TCP/IP related socket options will not apply.
Parameters
host | the IP address. |
---|---|
port | the port number. |
stream | if true , create a stream socket;
otherwise, create a datagram socket. |
Throws
IOException | if an I/O error occurs when creating the socket. |
---|---|
SecurityException | if a security manager exists and its
checkConnect method doesn't allow the operation. |
IllegalArgumentException | if the port parameter is outside the specified range of valid port values, which is between 0 and 65535, inclusive. |
NullPointerException | if host is null. |
Protected Constructors
protected Socket (SocketImpl impl)
Creates an unconnected Socket with a user-specified SocketImpl.
Parameters
impl | an instance of a SocketImpl the subclass wishes to use on the Socket. |
---|
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
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Public Methods
public void bind (SocketAddress bindpoint)
Binds the socket to a local address.
If the address is null
, then the system will pick up
an ephemeral port and a valid local address to bind the socket.
Parameters
bindpoint | the SocketAddress to bind to |
---|
Throws
IOException | if the bind operation fails, or if the socket is already bound. |
---|---|
IllegalArgumentException | if bindpoint is a SocketAddress subclass not supported by this socket |
SecurityException | if a security manager exists and its
checkListen method doesn't allow the bind
to the local port. |
See Also
public synchronized void close ()
Closes this socket.
Any thread currently blocked in an I/O operation upon this socket
will throw a SocketException
.
Once a socket has been closed, it is not available for further networking use (i.e. can't be reconnected or rebound). A new socket needs to be created.
Closing this socket will also close the socket's
InputStream
and
OutputStream
.
If this socket has an associated channel then the channel is closed as well.
Throws
IOException | if an I/O error occurs when closing this socket. |
---|
See Also
public void connect (SocketAddress endpoint, int timeout)
Connects this socket to the server with a specified timeout value. A timeout of zero is interpreted as an infinite timeout. The connection will then block until established or an error occurs.
Parameters
endpoint | the SocketAddress |
---|---|
timeout | the timeout value to be used in milliseconds. |
Throws
IOException | if an error occurs during the connection |
---|---|
SocketTimeoutException | if timeout expires before connecting |
IllegalBlockingModeException | if this socket has an associated channel, and the channel is in non-blocking mode |
IllegalArgumentException | if endpoint is null or is a SocketAddress subclass not supported by this socket |
public void connect (SocketAddress endpoint)
Connects this socket to the server.
Parameters
endpoint | the SocketAddress |
---|
Throws
IOException | if an error occurs during the connection |
---|---|
IllegalBlockingModeException | if this socket has an associated channel, and the channel is in non-blocking mode |
IllegalArgumentException | if endpoint is null or is a SocketAddress subclass not supported by this socket |
public SocketChannel getChannel ()
Returns the unique SocketChannel
object associated with this socket, if any.
A socket will have a channel if, and only if, the channel itself was
created via the SocketChannel.open
or ServerSocketChannel.accept
methods.
Returns
- the socket channel associated with this socket,
or
null
if this socket was not created for a channel
public InetAddress getInetAddress ()
Returns the address to which the socket is connected.
If the socket was connected prior to being closed
,
then this method will continue to return the connected address
after the socket is closed.
Returns
- the remote IP address to which this socket is connected,
or
null
if the socket is not connected.
public InputStream getInputStream ()
Returns an input stream for this socket.
If this socket has an associated channel then the resulting input
stream delegates all of its operations to the channel. If the channel
is in non-blocking mode then the input stream's read
operations
will throw an IllegalBlockingModeException
.
Under abnormal conditions the underlying connection may be broken by the remote host or the network software (for example a connection reset in the case of TCP connections). When a broken connection is detected by the network software the following applies to the returned input stream :-
The network software may discard bytes that are buffered by the socket. Bytes that aren't discarded by the network software can be read using
read
.If there are no bytes buffered on the socket, or all buffered bytes have been consumed by
read
, then all subsequent calls toread
will throw anIOException
.If there are no bytes buffered on the socket, and the socket has not been closed using
close
, thenavailable
will return0
.
Closing the returned InputStream
will close the associated socket.
Returns
- an input stream for reading bytes from this socket.
Throws
IOException | if an I/O error occurs when creating the
input stream, the socket is closed, the socket is
not connected, or the socket input has been shutdown
using shutdownInput() |
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public boolean getKeepAlive ()
Tests if SO_KEEPALIVE
is enabled.
Returns
- a
boolean
indicating whether or notSO_KEEPALIVE
is enabled.
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|
See Also
public InetAddress getLocalAddress ()
Gets the local address to which the socket is bound.
If there is a security manager set, its checkConnect
method is
called with the local address and -1
as its arguments to see
if the operation is allowed. If the operation is not allowed,
the loopback
address is returned.
Returns
- the local address to which the socket is bound, the loopback address if denied by the security manager, or the wildcard address if the socket is closed or not bound yet.
public int getLocalPort ()
Returns the local port number to which this socket is bound.
If the socket was bound prior to being closed
,
then this method will continue to return the local port number
after the socket is closed.
Returns
- the local port number to which this socket is bound or -1 if the socket is not bound yet.
public SocketAddress getLocalSocketAddress ()
Returns the address of the endpoint this socket is bound to.
If a socket bound to an endpoint represented by an
InetSocketAddress
is closed
,
then this method will continue to return an InetSocketAddress
after the socket is closed. In that case the returned
InetSocketAddress
's address is the
wildcard
address
and its port is the local port that it was bound to.
If there is a security manager set, its checkConnect
method is
called with the local address and -1
as its arguments to see
if the operation is allowed. If the operation is not allowed,
a SocketAddress
representing the
loopback
address and the local
port to which this socket is bound is returned.
Returns
- a
SocketAddress
representing the local endpoint of this socket, or aSocketAddress
representing the loopback address if denied by the security manager, ornull
if the socket is not bound yet.
public boolean getOOBInline ()
Tests if SO_OOBINLINE
is enabled.
Returns
- a
boolean
indicating whether or notSO_OOBINLINE
is enabled.
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|
See Also
public OutputStream getOutputStream ()
Returns an output stream for this socket.
If this socket has an associated channel then the resulting output
stream delegates all of its operations to the channel. If the channel
is in non-blocking mode then the output stream's write
operations will throw an IllegalBlockingModeException
.
Closing the returned OutputStream
will close the associated socket.
Returns
- an output stream for writing bytes to this socket.
Throws
IOException | if an I/O error occurs when creating the output stream or if the socket is not connected. |
---|
public int getPort ()
Returns the remote port number to which this socket is connected.
If the socket was connected prior to being closed
,
then this method will continue to return the connected port number
after the socket is closed.
Returns
- the remote port number to which this socket is connected, or 0 if the socket is not connected yet.
public synchronized int getReceiveBufferSize ()
Gets the value of the SO_RCVBUF
option
for this Socket
, that is the buffer size used by the platform
for input on this Socket
.
Returns
- the value of the
SO_RCVBUF
option for thisSocket
.
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|
See Also
public SocketAddress getRemoteSocketAddress ()
Returns the address of the endpoint this socket is connected to, or
null
if it is unconnected.
If the socket was connected prior to being closed
,
then this method will continue to return the connected address
after the socket is closed.
Returns
- a
SocketAddress
representing the remote endpoint of this socket, ornull
if it is not connected yet.
public boolean getReuseAddress ()
Tests if SO_REUSEADDR
is enabled.
Returns
- a
boolean
indicating whether or notSO_REUSEADDR
is enabled.
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|
See Also
public synchronized int getSendBufferSize ()
Get value of the SO_SNDBUF
option
for this Socket
, that is the buffer size used by the platform
for output on this Socket
.
Returns
- the value of the
SO_SNDBUF
option for thisSocket
.
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|
See Also
public int getSoLinger ()
Returns setting for SO_LINGER
.
-1 returns implies that the
option is disabled.
The setting only affects socket close.
Returns
- the setting for
SO_LINGER
.
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|
See Also
public synchronized int getSoTimeout ()
Returns setting for SO_TIMEOUT
.
0 returns implies that the option is disabled (i.e., timeout of infinity).
Returns
- the setting for
SO_TIMEOUT
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|
See Also
public boolean getTcpNoDelay ()
Tests if TCP_NODELAY
is enabled.
Returns
- a
boolean
indicating whether or notTCP_NODELAY
is enabled.
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|
See Also
public int getTrafficClass ()
Gets traffic class or type-of-service in the IP header for packets sent from this Socket
As the underlying network implementation may ignore the
traffic class or type-of-service set using setTrafficClass(int)
this method may return a different value than was previously
set using the setTrafficClass(int)
method on this Socket.
Returns
- the traffic class or type-of-service already set
Throws
SocketException | if there is an error obtaining the traffic class or type-of-service value. |
---|
public boolean isBound ()
Returns the binding state of the socket.
Note: Closing a socket doesn't clear its binding state, which means
this method will return true
for a closed socket
(see isClosed()
) if it was successfuly bound prior
to being closed.
Returns
- true if the socket was successfuly bound to an address
See Also
public boolean isClosed ()
public boolean isConnected ()
Returns the connection state of the socket.
Note: Closing a socket doesn't clear its connection state, which means
this method will return true
for a closed socket
(see isClosed()
) if it was successfuly connected prior
to being closed.
Returns
- true if the socket was successfuly connected to a server
public boolean isInputShutdown ()
Returns whether the read-half of the socket connection is closed.
Returns
- true if the input of the socket has been shutdown
See Also
public boolean isOutputShutdown ()
Returns whether the write-half of the socket connection is closed.
Returns
- true if the output of the socket has been shutdown
See Also
public void sendUrgentData (int data)
Send one byte of urgent data on the socket. The byte to be sent is the lowest eight bits of the data parameter. The urgent byte is sent after any preceding writes to the socket OutputStream and before any future writes to the OutputStream.
Parameters
data | The byte of data to send |
---|
Throws
IOException | if there is an error sending the data. |
---|
public void setKeepAlive (boolean on)
Enable/disable SO_KEEPALIVE
.
Parameters
on | whether or not to have socket keep alive turned on. |
---|
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|
See Also
public void setOOBInline (boolean on)
Enable/disable SO_OOBINLINE
(receipt of TCP urgent data)
By default, this option is disabled and TCP urgent data received on a
socket is silently discarded. If the user wishes to receive urgent data, then
this option must be enabled. When enabled, urgent data is received
inline with normal data.
Note, only limited support is provided for handling incoming urgent data. In particular, no notification of incoming urgent data is provided and there is no capability to distinguish between normal data and urgent data unless provided by a higher level protocol.
Parameters
on | true to enable
SO_OOBINLINE ,
false to disable. |
---|
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|
See Also
public 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)
.
Invoking this method after this socket has been connected will have no effect.
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 |
public synchronized void setReceiveBufferSize (int size)
Sets the SO_RCVBUF
option to the
specified value for this Socket
. The
SO_RCVBUF
option is
used by the platform's networking code as a hint for the size to set
the underlying network I/O buffers.
Increasing the receive buffer size can increase the performance of network I/O for high-volume connection, while decreasing it can help reduce the backlog of incoming data.
Because SO_RCVBUF
is a hint,
applications that want to verify what size the buffers were set to
should call getReceiveBufferSize()
.
The value of SO_RCVBUF
is also used
to set the TCP receive window that is advertized to the remote peer.
Generally, the window size can be modified at any time when a socket is
connected. However, if a receive window larger than 64K is required then
this must be requested before the socket is connected to the
remote peer. There are two cases to be aware of:
- For sockets accepted from a ServerSocket, this must be done by calling
ServerSocket.setReceiveBufferSize(int)
before the ServerSocket is bound to a local address. - For client sockets, setReceiveBufferSize() must be called before connecting the socket to its remote peer.
Parameters
size | the size to which to set the receive buffer size. This value must be greater than 0. |
---|
Throws
IllegalArgumentException | if the value is 0 or is negative. |
---|---|
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
public void setReuseAddress (boolean on)
Enable/disable the SO_REUSEADDR
socket option.
When a TCP connection is closed the connection may remain
in a timeout state for a period of time after the connection
is closed (typically known as the TIME_WAIT
state
or 2MSL
wait state).
For applications using a well known socket address or port
it may not be possible to bind a socket to the required
SocketAddress
if there is a connection in the
timeout state involving the socket address or port.
Enabling SO_REUSEADDR
prior to binding the socket using bind(SocketAddress)
allows
the socket to be bound even though a previous connection is in a timeout
state.
When a Socket
is created the initial setting
of SO_REUSEADDR
is disabled.
The behaviour when SO_REUSEADDR
is
enabled or disabled after a socket is bound (See isBound()
)
is not defined.
Parameters
on | whether to enable or disable the socket option |
---|
Throws
SocketException | if an error occurs enabling or
disabling the SO_REUSEADDR
socket option, or the socket is closed. |
---|
public synchronized void setSendBufferSize (int size)
Sets the SO_SNDBUF
option to the
specified value for this Socket
.
The SO_SNDBUF
option is used by the
platform's networking code as a hint for the size to set the underlying
network I/O buffers.
Because SO_SNDBUF
is a hint,
applications that want to verify what size the buffers were set to
should call getSendBufferSize()
.
Parameters
size | the size to which to set the send buffer size. This value must be greater than 0. |
---|
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|---|
IllegalArgumentException | if the value is 0 or is negative. |
See Also
public void setSoLinger (boolean on, int linger)
Enable/disable SO_LINGER
with the
specified linger time in seconds. The maximum timeout value is platform
specific.
The setting only affects socket close.
Parameters
on | whether or not to linger on. |
---|---|
linger | how long to linger for, if on is true. |
Throws
SocketException | if there is an error in the underlying protocol, such as a TCP error. |
---|---|
IllegalArgumentException | if the linger value is negative. |
See Also
public synchronized void setSoTimeout (int timeout)
Enable/disable SO_TIMEOUT
with the specified timeout, in milliseconds. With this option set
to a non-zero timeout, a read() call on the InputStream associated with
this Socket will block for only this amount of time. If the timeout
expires, a java.net.SocketTimeoutException is raised, though the
Socket is still valid. The option must be enabled
prior to entering the blocking operation to have effect. The
timeout must be > 0
.
A timeout of zero is interpreted as an infinite timeout.