JDK8/Java8源码在线阅读
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package java.net;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
import java.nio.channels.SocketChannel;
import java.security.AccessController;
import java.security.PrivilegedExceptionAction;
import java.security.PrivilegedAction;
/**
* This class implements client sockets (also called just
* "sockets"). A socket is an endpoint for communication
* between two machines.
* <p>
* The actual work of the socket is performed by an instance of the
* {@code 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.
*
* @author unascribed
* @see java.net.Socket#setSocketImplFactory(java.net.SocketImplFactory)
* @see java.net.SocketImpl
* @see java.nio.channels.SocketChannel
* @since JDK1.0
*/
public
class Socket implements java.io.Closeable {
/**
* Various states of this socket.
*/
private boolean created = false;
private boolean bound = false;
private boolean connected = false;
private boolean closed = false;
private Object closeLock = new Object();
private boolean shutIn = false;
private boolean shutOut = false;
/**
* The implementation of this Socket.
*/
SocketImpl impl;
/**
* Are we using an older SocketImpl?
*/
private boolean oldImpl = false;
/**
* Creates an unconnected socket, with the
* system-default type of SocketImpl.
*
* @since JDK1.1
* @revised 1.4
*/
public Socket() {
setImpl();
}
/**
* Creates an unconnected socket, specifying the type of proxy, if any,
* that should be used regardless of any other settings.
* <P>
* If there is a security manager, its {@code checkConnect} method
* is called with the proxy host address and port number
* as its arguments. This could result in a SecurityException.
* <P>
* Examples:
* <UL> <LI>{@code Socket s = new Socket(Proxy.NO_PROXY);} will create
* a plain socket ignoring any other proxy configuration.</LI>
* <LI>{@code 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.</LI>
* </UL>
*
* @param proxy a {@link java.net.Proxy Proxy} object specifying what kind
* of proxying should be used.
* @throws IllegalArgumentException if the proxy is of an invalid type
* or {@code null}.
* @throws SecurityException if a security manager is present and
* permission to connect to the proxy is
* denied.
* @see java.net.ProxySelector
* @see java.net.Proxy
*
* @since 1.5
*/
public Socket(Proxy proxy) {
// Create a copy of Proxy as a security measure
if (proxy == null) {
throw new IllegalArgumentException("Invalid Proxy");
}
Proxy p = proxy == Proxy.NO_PROXY ? Proxy.NO_PROXY
: sun.net.ApplicationProxy.create(proxy);
Proxy.Type type = p.type();
if (type == Proxy.Type.SOCKS || type == Proxy.Type.HTTP) {
SecurityManager security = System.getSecurityManager();
InetSocketAddress epoint = (InetSocketAddress) p.address();
if (epoint.getAddress() != null) {
checkAddress (epoint.getAddress(), "Socket");
}
if (security != null) {
if (epoint.isUnresolved())
epoint = new InetSocketAddress(epoint.getHostName(), epoint.getPort());
if (epoint.isUnresolved())
security.checkConnect(epoint.getHostName(), epoint.getPort());
else
security.checkConnect(epoint.getAddress().getHostAddress(),
epoint.getPort());
}
impl = type == Proxy.Type.SOCKS ? new SocksSocketImpl(p)
: new HttpConnectSocketImpl(p);
impl.setSocket(this);
} else {
if (p == Proxy.NO_PROXY) {
if (factory == null) {
impl = new PlainSocketImpl();
impl.setSocket(this);
} else
setImpl();
} else
throw new IllegalArgumentException("Invalid Proxy");
}
}
/**
* Creates an unconnected Socket with a user-specified
* SocketImpl.
* <P>
* @param impl an instance of a <B>SocketImpl</B>
* the subclass wishes to use on the Socket.
*
* @exception SocketException if there is an error in the underlying protocol,
* such as a TCP error.
* @since JDK1.1
*/
protected Socket(SocketImpl impl) throws SocketException {
this.impl = impl;
if (impl != null) {
checkOldImpl();
this.impl.setSocket(this);
}
}
/**
* Creates a stream socket and connects it to the specified port
* number on the named host.
* <p>
* If the specified host is {@code null} it is the equivalent of
* specifying the address as
* {@link java.net.InetAddress#getByName InetAddress.getByName}{@code (null)}.
* In other words, it is equivalent to specifying an address of the
* loopback interface. </p>
* <p>
* If the application has specified a server socket factory, that
* factory's {@code createSocketImpl} method is called to create
* the actual socket implementation. Otherwise a "plain" socket is created.
* <p>
* If there is a security manager, its
* {@code checkConnect} method is called
* with the host address and {@code port}
* as its arguments. This could result in a SecurityException.
*
* @param host the host name, or {@code null} for the loopback address.
* @param port the port number.
*
* @exception UnknownHostException if the IP address of
* the host could not be determined.
*
* @exception IOException if an I/O error occurs when creating the socket.
* @exception SecurityException if a security manager exists and its
* {@code checkConnect} method doesn't allow the operation.
* @exception IllegalArgumentException if the port parameter is outside
* the specified range of valid port values, which is between
* 0 and 65535, inclusive.
* @see java.net.Socket#setSocketImplFactory(java.net.SocketImplFactory)
* @see java.net.SocketImpl
* @see java.net.SocketImplFactory#createSocketImpl()
* @see SecurityManager#checkConnect
*/
public Socket(String host, int port)
throws UnknownHostException, IOException
{
this(host != null ? new InetSocketAddress(host, port) :
new InetSocketAddress(InetAddress.getByName(null), port),
(SocketAddress) null, true);
}
/**
* Creates a stream socket and connects it to the specified port
* number at the specified IP address.
* <p>
* If the application has specified a socket factory, that factory's
* {@code createSocketImpl} method is called to create the
* actual socket implementation. Otherwise a "plain" socket is created.
* <p>
* If there is a security manager, its
* {@code checkConnect} method is called
* with the host address and {@code port}
* as its arguments. This could result in a SecurityException.
*
* @param address the IP address.
* @param port the port number.
* @exception IOException if an I/O error occurs when creating the socket.
* @exception SecurityException if a security manager exists and its
* {@code checkConnect} method doesn't allow the operation.
* @exception IllegalArgumentException if the port parameter is outside
* the specified range of valid port values, which is between
* 0 and 65535, inclusive.
* @exception NullPointerException if {@code address} is null.
* @see java.net.Socket#setSocketImplFactory(java.net.SocketImplFactory)
* @see java.net.SocketImpl
* @see java.net.SocketImplFactory#createSocketImpl()
* @see SecurityManager#checkConnect
*/
public Socket(InetAddress address, int port) throws IOException {
this(address != null ? new InetSocketAddress(address, port) : null,
(SocketAddress) null, true);
}
/**
* 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.
* <p>
* If the specified host is {@code null} it is the equivalent of
* specifying the address as
* {@link java.net.InetAddress#getByName InetAddress.getByName}{@code (null)}.
* In other words, it is equivalent to specifying an address of the
* loopback interface. </p>
* <p>
* A local port number of {@code zero} will let the system pick up a
* free port in the {@code bind} operation.</p>
* <p>
* If there is a security manager, its
* {@code checkConnect} method is called
* with the host address and {@code port}
* as its arguments. This could result in a SecurityException.
*
* @param host the name of the remote host, or {@code null} for the loopback address.
* @param port the remote port
* @param localAddr the local address the socket is bound to, or
* {@code null} for the {@code anyLocal} address.
* @param localPort the local port the socket is bound to, or
* {@code zero} for a system selected free port.
* @exception IOException if an I/O error occurs when creating the socket.
* @exception SecurityException if a security manager exists and its
* {@code checkConnect} method doesn't allow the connection
* to the destination, or if its {@code checkListen} method
* doesn't allow the bind to the local port.
* @exception IllegalArgumentException if the port parameter or localPort
* parameter is outside the specified range of valid port values,
* which is between 0 and 65535, inclusive.
* @see SecurityManager#checkConnect
* @since JDK1.1
*/
public Socket(String host, int port, InetAddress localAddr,
int localPort) throws IOException {
this(host != null ? new InetSocketAddress(host, port) :
new InetSocketAddress(InetAddress.getByName(null), port),
new InetSocketAddress(localAddr, localPort), true);
}
/**
* 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.
* <p>
* If the specified local address is {@code null} it is the equivalent of
* specifying the address as the AnyLocal address
* (see {@link java.net.InetAddress#isAnyLocalAddress InetAddress.isAnyLocalAddress}{@code ()}).
* <p>
* A local port number of {@code zero} will let the system pick up a
* free port in the {@code bind} operation.</p>
* <p>
* If there is a security manager, its
* {@code checkConnect} method is called
* with the host address and {@code port}
* as its arguments. This could result in a SecurityException.
*
* @param address the remote address
* @param port the remote port
* @param localAddr the local address the socket is bound to, or
* {@code null} for the {@code anyLocal} address.
* @param localPort the local port the socket is bound to or
* {@code zero} for a system selected free port.
* @exception IOException if an I/O error occurs when creating the socket.
* @exception SecurityException if a security manager exists and its
* {@code checkConnect} method doesn't allow the connection
* to the destination, or if its {@code checkListen} method
* doesn't allow the bind to the local port.
* @exception IllegalArgumentException if the port parameter or localPort
* parameter is outside the specified range of valid port values,
* which is between 0 and 65535, inclusive.
* @exception NullPointerException if {@code address} is null.
* @see SecurityManager#checkConnect
* @since JDK1.1
*/
public Socket(InetAddress address, int port, InetAddress localAddr,
int localPort) throws IOException {
this(address != null ? new InetSocketAddress(address, port) : null,
new InetSocketAddress(localAddr, localPort), true);
}
/**
* Creates a stream socket and connects it to the specified port
* number on the named host.
* <p>
* If the specified host is {@code null} it is the equivalent of
* specifying the address as
* {@link java.net.InetAddress#getByName InetAddress.getByName}{@code (null)}.
* In other words, it is equivalent to specifying an address of the
* loopback interface. </p>
* <p>
* If the stream argument is {@code true}, this creates a
* stream socket. If the stream argument is {@code false}, it
* creates a datagram socket.
* <p>
* If the application has specified a server socket factory, that
* factory's {@code createSocketImpl} method is called to create
* the actual socket implementation. Otherwise a "plain" socket is created.
* <p>
* If there is a security manager, its
* {@code checkConnect} method is called
* with the host address and {@code port}
* as its arguments. This could result in a SecurityException.
* <p>
* If a UDP socket is used, TCP/IP related socket options will not apply.
*
* @param host the host name, or {@code null} for the loopback address.
* @param port the port number.
* @param stream a {@code boolean} indicating whether this is
* a stream socket or a datagram socket.
* @exception IOException if an I/O error occurs when creating the socket.
* @exception SecurityException if a security manager exists and its
* {@code checkConnect} method doesn't allow the operation.
* @exception IllegalArgumentException if the port parameter is outside
* the specified range of valid port values, which is between
* 0 and 65535, inclusive.
* @see java.net.Socket#setSocketImplFactory(java.net.SocketImplFactory)
* @see java.net.SocketImpl
* @see java.net.SocketImplFactory#createSocketImpl()
* @see SecurityManager#checkConnect
* @deprecated Use DatagramSocket instead for UDP transport.
*/
@Deprecated
public Socket(String host, int port, boolean stream) throws IOException {
this(host != null ? new InetSocketAddress(host, port) :
new InetSocketAddress(InetAddress.getByName(null), port),
(SocketAddress) null, stream);
}
/**
* Creates a socket and connects it to the specified port number at
* the specified IP address.
* <p>
* If the stream argument is {@code true}, this creates a
* stream socket. If the stream argument is {@code false}, it
* creates a datagram socket.
* <p>
* If the application has specified a server socket factory, that
* factory's {@code createSocketImpl} method is called to create
* the actual socket implementation. Otherwise a "plain" socket is created.
*
* <p>If there is a security manager, its
* {@code checkConnect} method is called
* with {@code host.getHostAddress()} and {@code port}
* as its arguments. This could result in a SecurityException.
* <p>
* If UDP socket is used, TCP/IP related socket options will not apply.
*
* @param host the IP address.
* @param port the port number.
* @param stream if {@code true}, create a stream socket;
* otherwise, create a datagram socket.
* @exception IOException if an I/O error occurs when creating the socket.
* @exception SecurityException if a security manager exists and its
* {@code checkConnect} method doesn't allow the operation.
* @exception IllegalArgumentException if the port parameter is outside
* the specified range of valid port values, which is between
* 0 and 65535, inclusive.
* @exception NullPointerException if {@code host} is null.
* @see java.net.Socket#setSocketImplFactory(java.net.SocketImplFactory)
* @see java.net.SocketImpl
* @see java.net.SocketImplFactory#createSocketImpl()
* @see SecurityManager#checkConnect
* @deprecated Use DatagramSocket instead for UDP transport.
*/
@Deprecated
public Socket(InetAddress host, int port, boolean stream) throws IOException {
this(host != null ? new InetSocketAddress(host, port) : null,
new InetSocketAddress(0), stream);
}
private Socket(SocketAddress address, SocketAddress localAddr,
boolean stream) throws IOException {
setImpl();
// backward compatibility
if (address == null)
throw new NullPointerException();
try {
createImpl(stream);
if (localAddr != null)
bind(localAddr);
connect(address);
} catch (IOException | IllegalArgumentException | SecurityException e) {
try {
close();
} catch (IOException ce) {
e.addSuppressed(ce);
}
throw e;
}
}
/**
* Creates the socket implementation.
*
* @param stream a {@code boolean} value : {@code true} for a TCP socket,
* {@code false} for UDP.
* @throws IOException if creation fails
* @since 1.4
*/
void createImpl(boolean stream) throws SocketException {
if (impl == null)
setImpl();
try {
impl.create(stream);
created = true;
} catch (IOException e) {
throw new SocketException(e.getMessage());
}
}
private void checkOldImpl() {
if (impl == null)
return;
// SocketImpl.connect() is a protected method, therefore we need to use
// getDeclaredMethod, therefore we need permission to access the member
oldImpl = AccessController.doPrivileged
(new PrivilegedAction<Boolean>() {
public Boolean run() {
Class<?> clazz = impl.getClass();
while (true) {
try {
clazz.getDeclaredMethod("connect", SocketAddress.class, int.class);
return Boolean.FALSE;
} catch (NoSuchMethodException e) {
clazz = clazz.getSuperclass();
// java.net.SocketImpl class will always have this abstract method.
// If we have not found it by now in the hierarchy then it does not
// exist, we are an old style impl.
if (clazz.equals(java.net.SocketImpl.class)) {
return Boolean.TRUE;
}
}
}
}
});
}
/**
* Sets impl to the system-default type of SocketImpl.
* @since 1.4
*/
void setImpl() {
if (factory != null) {
impl = factory.createSocketImpl();
checkOldImpl();
} else {
// No need to do a checkOldImpl() here, we know it's an up to date
// SocketImpl!
impl = new SocksSocketImpl();
}
if (impl != null)
impl.setSocket(this);
}
/**
* Get the {@code SocketImpl} attached to this socket, creating
* it if necessary.
*
* @return the {@code SocketImpl} attached to that ServerSocket.
* @throws SocketException if creation fails
* @since 1.4
*/
SocketImpl getImpl() throws SocketException {
if (!created)
createImpl(true);
return impl;
}
/**
* Connects this socket to the server.
*
* @param endpoint the {@code SocketAddress}
* @throws IOException if an error occurs during the connection
* @throws java.nio.channels.IllegalBlockingModeException
* if this socket has an associated channel,
* and the channel is in non-blocking mode
* @throws IllegalArgumentException if endpoint is null or is a
* SocketAddress subclass not supported by this socket
* @since 1.4
* @spec JSR-51
*/
public void connect(SocketAddress endpoint) throws IOException {
connect(endpoint, 0);
}
/**
* 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.
*
* @param endpoint the {@code SocketAddress}
* @param timeout the timeout value to be used in milliseconds.
* @throws IOException if an error occurs during the connection
* @throws SocketTimeoutException if timeout expires before connecting
* @throws java.nio.channels.IllegalBlockingModeException
* if this socket has an associated channel,
* and the channel is in non-blocking mode
* @throws IllegalArgumentException if endpoint is null or is a
* SocketAddress subclass not supported by this socket
* @since 1.4
* @spec JSR-51
*/
public void connect(SocketAddress endpoint, int timeout) throws IOException {
if (endpoint == null)
throw new IllegalArgumentException("connect: The address can't be null");
if (timeout < 0)
throw new IllegalArgumentException("connect: timeout can't be negative");
if (isClosed())
throw new SocketException("Socket is closed");
if (!oldImpl && isConnected())
throw new SocketException("already connected");
if (!(endpoint instanceof InetSocketAddress))
throw new IllegalArgumentException("Unsupported address type");
InetSocketAddress epoint = (InetSocketAddress) endpoint;
InetAddress addr = epoint.getAddress ();
int port = epoint.getPort();
checkAddress(addr, "connect");
SecurityManager security = System.getSecurityManager();
if (security != null) {
if (epoint.isUnresolved())
security.checkConnect(epoint.getHostName(), port);
else
security.checkConnect(addr.getHostAddress(), port);
}
if (!created)
createImpl(true);
if (!oldImpl)
impl.connect(epoint, timeout);
else if (timeout == 0) {
if (epoint.isUnresolved())
impl.connect(addr.getHostName(), port);
else
impl.connect(addr, port);
} else
throw new UnsupportedOperationException("SocketImpl.connect(addr, timeout)");
connected = true;
/*
* If the socket was not bound before the connect, it is now because
* the kernel will have picked an ephemeral port & a local address
*/
bound = true;
}
/**
* Binds the socket to a local address.
* <P>
* If the address is {@code null}, then the system will pick up
* an ephemeral port and a valid local address to bind the socket.
*
* @param bindpoint the {@code SocketAddress} to bind to
* @throws IOException if the bind operation fails, or if the socket
* is already bound.
* @throws IllegalArgumentException if bindpoint is a
* SocketAddress subclass not supported by this socket
* @throws SecurityException if a security manager exists and its
* {@code checkListen} method doesn't allow the bind
* to the local port.
*
* @since 1.4
* @see #isBound
*/
public void bind(SocketAddress bindpoint) throws IOException {
if (isClosed())
throw new SocketException("Socket is closed");
if (!oldImpl && isBound())
throw new SocketException("Already bound");
if (bindpoint != null && (!(bindpoint instanceof InetSocketAddress)))
throw new IllegalArgumentException("Unsupported address type");
InetSocketAddress epoint = (InetSocketAddress) bindpoint;
if (epoint != null && epoint.isUnresolved())
throw new SocketException("Unresolved address");
if (epoint == null) {
epoint = new InetSocketAddress(0);
}
InetAddress addr = epoint.getAddress();
int port = epoint.getPort();
checkAddress (addr, "bind");
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkListen(port);
}
getImpl().bind (addr, port);
bound = true;
}
private void checkAddress (InetAddress addr, String op) {
if (addr == null) {
return;
}
if (!(addr instanceof Inet4Address || addr instanceof Inet6Address)) {
throw new IllegalArgumentException(op + ": invalid address type");
}
}
/**
* set the flags after an accept() call.
*/
final void postAccept() {
connected = true;
created = true;
bound = true;
}
void setCreated() {
created = true;
}
void setBound() {
bound = true;
}
void setConnected() {
connected = true;
}
/**
* Returns the address to which the socket is connected.
* <p>
* If the socket was connected prior to being {@link #close closed},
* then this method will continue to return the connected address
* after the socket is closed.
*
* @return the remote IP address to which this socket is connected,
* or {@code null} if the socket is not connected.
*/
public InetAddress getInetAddress() {
if (!isConnected())
return null;
try {
return getImpl().getInetAddress();
} catch (SocketException e) {
}
return null;
}
/**
* Gets the local address to which the socket is bound.
* <p>
* If there is a security manager set, its {@code checkConnect} method is
* called with the local address and {@code -1} as its arguments to see
* if the operation is allowed. If the operation is not allowed,
* the {@link InetAddress#getLoopbackAddress loopback} address is returned.
*
* @return 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.
* @since JDK1.1
*
* @see SecurityManager#checkConnect
*/
public InetAddress getLocalAddress() {
// This is for backward compatibility
if (!isBound())
return InetAddress.anyLocalAddress();
InetAddress in = null;
try {
in = (InetAddress) getImpl().getOption(SocketOptions.SO_BINDADDR);
SecurityManager sm = System.getSecurityManager();
if (sm != null)
sm.checkConnect(in.getHostAddress(), -1);
if (in.isAnyLocalAddress()) {
in = InetAddress.anyLocalAddress();
}
} catch (SecurityException e) {
in = InetAddress.getLoopbackAddress();
} catch (Exception e) {
in = InetAddress.anyLocalAddress(); // "0.0.0.0"
}
return in;
}
/**
* Returns the remote port number to which this socket is connected.
* <p>
* If the socket was connected prior to being {@link #close closed},
* then this method will continue to return the connected port number
* after the socket is closed.
*
* @return the remote port number to which this socket is connected, or
* 0 if the socket is not connected yet.
*/
public int getPort() {
if (!isConnected())
return 0;
try {
return getImpl().getPort();
} catch (SocketException e) {
// Shouldn't happen as we're connected
}
return -1;
}
/**
* Returns the local port number to which this socket is bound.
* <p>
* If the socket was bound prior to being {@link #close closed},
* then this method will continue to return the local port number
* after the socket is closed.
*
* @return the local port number to which this socket is bound or -1
* if the socket is not bound yet.
*/
public int getLocalPort() {
if (!isBound())
return -1;
try {
return getImpl().getLocalPort();
} catch(SocketException e) {
// shouldn't happen as we're bound
}
return -1;
}
/**
* Returns the address of the endpoint this socket is connected to, or
* {@code null} if it is unconnected.
* <p>
* If the socket was connected prior to being {@link #close closed},
* then this method will continue to return the connected address
* after the socket is closed.
*
* @return a {@code SocketAddress} representing the remote endpoint of this
* socket, or {@code null} if it is not connected yet.
* @see #getInetAddress()
* @see #getPort()
* @see #connect(SocketAddress, int)
* @see #connect(SocketAddress)
* @since 1.4
*/
public SocketAddress getRemoteSocketAddress() {
if (!isConnected())
return null;
return new InetSocketAddress(getInetAddress(), getPort());
}
/**
* Returns the address of the endpoint this socket is bound to.
* <p>
* If a socket bound to an endpoint represented by an
* {@code InetSocketAddress } is {@link #close closed},
* then this method will continue to return an {@code InetSocketAddress}
* after the socket is closed. In that case the returned
* {@code InetSocketAddress}'s address is the
* {@link InetAddress#isAnyLocalAddress wildcard} address
* and its port is the local port that it was bound to.
* <p>
* If there is a security manager set, its {@code checkConnect} method is
* called with the local address and {@code -1} as its arguments to see
* if the operation is allowed. If the operation is not allowed,
* a {@code SocketAddress} representing the
* {@link InetAddress#getLoopbackAddress loopback} address and the local
* port to which this socket is bound is returned.
*
* @return a {@code SocketAddress} representing the local endpoint of
* this socket, or a {@code SocketAddress} representing the
* loopback address if denied by the security manager, or
* {@code null} if the socket is not bound yet.
*
* @see #getLocalAddress()
* @see #getLocalPort()
* @see #bind(SocketAddress)
* @see SecurityManager#checkConnect
* @since 1.4
*/
public SocketAddress getLocalSocketAddress() {
if (!isBound())
return null;
return new InetSocketAddress(getLocalAddress(), getLocalPort());
}
/**
* Returns the unique {@link java.nio.channels.SocketChannel SocketChannel}
* object associated with this socket, if any.
*
* <p> A socket will have a channel if, and only if, the channel itself was
* created via the {@link java.nio.channels.SocketChannel#open
* SocketChannel.open} or {@link
* java.nio.channels.ServerSocketChannel#accept ServerSocketChannel.accept}
* methods.
*
* @return the socket channel associated with this socket,
* or {@code null} if this socket was not created
* for a channel
*
* @since 1.4
* @spec JSR-51
*/
public SocketChannel getChannel() {
return null;
}
/**
* Returns an input stream for this socket.
*
* <p> 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 {@code read} operations
* will throw an {@link java.nio.channels.IllegalBlockingModeException}.
*
* <p>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 :-
*
* <ul>
*
* <li><p>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 {@link java.io.InputStream#read read}.
*
* <li><p>If there are no bytes buffered on the socket, or all
* buffered bytes have been consumed by
* {@link java.io.InputStream#read read}, then all subsequent
* calls to {@link java.io.InputStream#read read} will throw an
* {@link java.io.IOException IOException}.
*
* <li><p>If there are no bytes buffered on the socket, and the
* socket has not been closed using {@link #close close}, then
* {@link java.io.InputStream#available available} will
* return {@code 0}.
*
* </ul>
*
* <p> Closing the returned {@link java.io.InputStream InputStream}
* will close the associated socket.
*
* @return an input stream for reading bytes from this socket.
* @exception 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 {@link #shutdownInput()}
*
* @revised 1.4
* @spec JSR-51
*/
public InputStream getInputStream() throws IOException {
if (isClosed())
throw new SocketException("Socket is closed");
if (!isConnected())
throw new SocketException("Socket is not connected");
if (isInputShutdown())
throw new SocketException("Socket input is shutdown");
final Socket s = this;
InputStream is = null;
try {
is = AccessController.doPrivileged(
new PrivilegedExceptionAction<InputStream>() {
public InputStream run() throws IOException {
return impl.getInputStream();
}
});
} catch (java.security.PrivilegedActionException e) {
throw (IOException) e.getException();
}
return is;
}
/**
* Returns an output stream for this socket.
*
* <p> 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 {@code write}
* operations will throw an {@link
* java.nio.channels.IllegalBlockingModeException}.
*
* <p> Closing the returned {@link java.io.OutputStream OutputStream}
* will close the associated socket.
*
* @return an output stream for writing bytes to this socket.
* @exception IOException if an I/O error occurs when creating the
* output stream or if the socket is not connected.
* @revised 1.4
* @spec JSR-51
*/
public OutputStream getOutputStream() throws IOException {
if (isClosed())
throw new SocketException("Socket is closed");
if (!isConnected())
throw new SocketException("Socket is not connected");
if (isOutputShutdown())
throw new SocketException("Socket output is shutdown");
final Socket s = this;
OutputStream os = null;
try {
os = AccessController.doPrivileged(
new PrivilegedExceptionAction<OutputStream>() {
public OutputStream run() throws IOException {
return impl.getOutputStream();
}
});
} catch (java.security.PrivilegedActionException e) {
throw (IOException) e.getException();
}
return os;
}
/**
* Enable/disable {@link SocketOptions#TCP_NODELAY TCP_NODELAY}
* (disable/enable Nagle's algorithm).
*
* @param on {@code true} to enable TCP_NODELAY,
* {@code false} to disable.
*
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
*
* @since JDK1.1
*
* @see #getTcpNoDelay()
*/
public void setTcpNoDelay(boolean on) throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.TCP_NODELAY, Boolean.valueOf(on));
}
/**
* Tests if {@link SocketOptions#TCP_NODELAY TCP_NODELAY} is enabled.
*
* @return a {@code boolean} indicating whether or not
* {@link SocketOptions#TCP_NODELAY TCP_NODELAY} is enabled.
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
* @since JDK1.1
* @see #setTcpNoDelay(boolean)
*/
public boolean getTcpNoDelay() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
return ((Boolean) getImpl().getOption(SocketOptions.TCP_NODELAY)).booleanValue();
}
/**
* Enable/disable {@link SocketOptions#SO_LINGER SO_LINGER} with the
* specified linger time in seconds. The maximum timeout value is platform
* specific.
*
* The setting only affects socket close.
*
* @param on whether or not to linger on.
* @param linger how long to linger for, if on is true.
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
* @exception IllegalArgumentException if the linger value is negative.
* @since JDK1.1
* @see #getSoLinger()
*/
public void setSoLinger(boolean on, int linger) throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
if (!on) {
getImpl().setOption(SocketOptions.SO_LINGER, new Boolean(on));
} else {
if (linger < 0) {
throw new IllegalArgumentException("invalid value for SO_LINGER");
}
if (linger > 65535)
linger = 65535;
getImpl().setOption(SocketOptions.SO_LINGER, new Integer(linger));
}
}
/**
* Returns setting for {@link SocketOptions#SO_LINGER SO_LINGER}.
* -1 returns implies that the
* option is disabled.
*
* The setting only affects socket close.
*
* @return the setting for {@link SocketOptions#SO_LINGER SO_LINGER}.
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
* @since JDK1.1
* @see #setSoLinger(boolean, int)
*/
public int getSoLinger() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
Object o = getImpl().getOption(SocketOptions.SO_LINGER);
if (o instanceof Integer) {
return ((Integer) o).intValue();
} else {
return -1;
}
}
/**
* 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.
* @param data The byte of data to send
* @exception IOException if there is an error
* sending the data.
* @since 1.4
*/
public void sendUrgentData (int data) throws IOException {
if (!getImpl().supportsUrgentData ()) {
throw new SocketException ("Urgent data not supported");
}
getImpl().sendUrgentData (data);
}
/**
* Enable/disable {@link SocketOptions#SO_OOBINLINE 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.
* <p>
* 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.
*
* @param on {@code true} to enable
* {@link SocketOptions#SO_OOBINLINE SO_OOBINLINE},
* {@code false} to disable.
*
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
*
* @since 1.4
*
* @see #getOOBInline()
*/
public void setOOBInline(boolean on) throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.SO_OOBINLINE, Boolean.valueOf(on));
}
/**
* Tests if {@link SocketOptions#SO_OOBINLINE SO_OOBINLINE} is enabled.
*
* @return a {@code boolean} indicating whether or not
* {@link SocketOptions#SO_OOBINLINE SO_OOBINLINE}is enabled.
*
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
* @since 1.4
* @see #setOOBInline(boolean)
*/
public boolean getOOBInline() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
return ((Boolean) getImpl().getOption(SocketOptions.SO_OOBINLINE)).booleanValue();
}
/**
* Enable/disable {@link SocketOptions#SO_TIMEOUT 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 <B>java.net.SocketTimeoutException</B> is raised, though the
* Socket is still valid. The option <B>must</B> be enabled
* prior to entering the blocking operation to have effect. The
* timeout must be {@code > 0}.
* A timeout of zero is interpreted as an infinite timeout.
*
* @param timeout the specified timeout, in milliseconds.
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
* @since JDK 1.1
* @see #getSoTimeout()
*/
public synchronized void setSoTimeout(int timeout) throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
if (timeout < 0)
throw new IllegalArgumentException("timeout can't be negative");
getImpl().setOption(SocketOptions.SO_TIMEOUT, new Integer(timeout));
}
/**
* Returns setting for {@link SocketOptions#SO_TIMEOUT SO_TIMEOUT}.
* 0 returns implies that the option is disabled (i.e., timeout of infinity).
*
* @return the setting for {@link SocketOptions#SO_TIMEOUT SO_TIMEOUT}
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
*
* @since JDK1.1
* @see #setSoTimeout(int)
*/
public synchronized int getSoTimeout() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
Object o = getImpl().getOption(SocketOptions.SO_TIMEOUT);
/* extra type safety */
if (o instanceof Integer) {
return ((Integer) o).intValue();
} else {
return 0;
}
}
/**
* Sets the {@link SocketOptions#SO_SNDBUF SO_SNDBUF} option to the
* specified value for this {@code Socket}.
* The {@link SocketOptions#SO_SNDBUF 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.
*
* <p>Because {@link SocketOptions#SO_SNDBUF SO_SNDBUF} is a hint,
* applications that want to verify what size the buffers were set to
* should call {@link #getSendBufferSize()}.
*
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
*
* @param size the size to which to set the send buffer
* size. This value must be greater than 0.
*
* @exception IllegalArgumentException if the
* value is 0 or is negative.
*
* @see #getSendBufferSize()
* @since 1.2
*/
public synchronized void setSendBufferSize(int size)
throws SocketException{
if (!(size > 0)) {
throw new IllegalArgumentException("negative send size");
}
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.SO_SNDBUF, new Integer(size));
}
/**
* Get value of the {@link SocketOptions#SO_SNDBUF SO_SNDBUF} option
* for this {@code Socket}, that is the buffer size used by the platform
* for output on this {@code Socket}.
* @return the value of the {@link SocketOptions#SO_SNDBUF SO_SNDBUF}
* option for this {@code Socket}.
*
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
*
* @see #setSendBufferSize(int)
* @since 1.2
*/
public synchronized int getSendBufferSize() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
int result = 0;
Object o = getImpl().getOption(SocketOptions.SO_SNDBUF);
if (o instanceof Integer) {
result = ((Integer)o).intValue();
}
return result;
}
/**
* Sets the {@link SocketOptions#SO_RCVBUF SO_RCVBUF} option to the
* specified value for this {@code Socket}. The
* {@link SocketOptions#SO_RCVBUF 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.
*
* <p>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.
*
* <p>Because {@link SocketOptions#SO_RCVBUF SO_RCVBUF} is a hint,
* applications that want to verify what size the buffers were set to
* should call {@link #getReceiveBufferSize()}.
*
* <p>The value of {@link SocketOptions#SO_RCVBUF 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 <B>before</B> the socket is connected to the
* remote peer. There are two cases to be aware of:
* <ol>
* <li>For sockets accepted from a ServerSocket, this must be done by calling
* {@link ServerSocket#setReceiveBufferSize(int)} before the ServerSocket
* is bound to a local address.<p></li>
* <li>For client sockets, setReceiveBufferSize() must be called before
* connecting the socket to its remote peer.</li></ol>
* @param size the size to which to set the receive buffer
* size. This value must be greater than 0.
*
* @exception IllegalArgumentException if the value is 0 or is
* negative.
*
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
*
* @see #getReceiveBufferSize()
* @see ServerSocket#setReceiveBufferSize(int)
* @since 1.2
*/
public synchronized void setReceiveBufferSize(int size)
throws SocketException{
if (size <= 0) {
throw new IllegalArgumentException("invalid receive size");
}
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.SO_RCVBUF, new Integer(size));
}
/**
* Gets the value of the {@link SocketOptions#SO_RCVBUF SO_RCVBUF} option
* for this {@code Socket}, that is the buffer size used by the platform
* for input on this {@code Socket}.
*
* @return the value of the {@link SocketOptions#SO_RCVBUF SO_RCVBUF}
* option for this {@code Socket}.
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
* @see #setReceiveBufferSize(int)
* @since 1.2
*/
public synchronized int getReceiveBufferSize()
throws SocketException{
if (isClosed())
throw new SocketException("Socket is closed");
int result = 0;
Object o = getImpl().getOption(SocketOptions.SO_RCVBUF);
if (o instanceof Integer) {
result = ((Integer)o).intValue();
}
return result;
}
/**
* Enable/disable {@link SocketOptions#SO_KEEPALIVE SO_KEEPALIVE}.
*
* @param on whether or not to have socket keep alive turned on.
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
* @since 1.3
* @see #getKeepAlive()
*/
public void setKeepAlive(boolean on) throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.SO_KEEPALIVE, Boolean.valueOf(on));
}
/**
* Tests if {@link SocketOptions#SO_KEEPALIVE SO_KEEPALIVE} is enabled.
*
* @return a {@code boolean} indicating whether or not
* {@link SocketOptions#SO_KEEPALIVE SO_KEEPALIVE} is enabled.
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
* @since 1.3
* @see #setKeepAlive(boolean)
*/
public boolean getKeepAlive() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
return ((Boolean) getImpl().getOption(SocketOptions.SO_KEEPALIVE)).booleanValue();
}
/**
* Sets traffic class or type-of-service octet in the IP
* header for packets sent from this Socket.
* As the underlying network implementation may ignore this
* value applications should consider it a hint.
*
* <P> The tc <B>must</B> be in the range {@code 0 <= tc <=
* 255} or an IllegalArgumentException will be thrown.
* <p>Notes:
* <p>For Internet Protocol v4 the value consists of an
* {@code integer}, the least significant 8 bits of which
* represent the value of the TOS octet in IP packets sent by
* the socket.
* RFC 1349 defines the TOS values as follows:
*
* <UL>
* <LI><CODE>IPTOS_LOWCOST (0x02)</CODE></LI>
* <LI><CODE>IPTOS_RELIABILITY (0x04)</CODE></LI>
* <LI><CODE>IPTOS_THROUGHPUT (0x08)</CODE></LI>
* <LI><CODE>IPTOS_LOWDELAY (0x10)</CODE></LI>
* </UL>
* The last low order bit is always ignored as this
* corresponds to the MBZ (must be zero) bit.
* <p>
* Setting bits in the precedence field may result in a
* SocketException indicating that the operation is not
* permitted.
* <p>
* As RFC 1122 section 4.2.4.2 indicates, a compliant TCP
* implementation should, but is not required to, let application
* change the TOS field during the lifetime of a connection.
* So whether the type-of-service field can be changed after the
* TCP connection has been established depends on the implementation
* in the underlying platform. Applications should not assume that
* they can change the TOS field after the connection.
* <p>
* For Internet Protocol v6 {@code tc} is the value that
* would be placed into the sin6_flowinfo field of the IP header.
*
* @param tc an {@code int} value for the bitset.
* @throws SocketException if there is an error setting the
* traffic class or type-of-service
* @since 1.4
* @see #getTrafficClass
* @see SocketOptions#IP_TOS
*/
public void setTrafficClass(int tc) throws SocketException {
if (tc < 0 || tc > 255)
throw new IllegalArgumentException("tc is not in range 0 -- 255");
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.IP_TOS, new Integer(tc));
}
/**
* Gets traffic class or type-of-service in the IP header
* for packets sent from this Socket
* <p>
* As the underlying network implementation may ignore the
* traffic class or type-of-service set using {@link #setTrafficClass(int)}
* this method may return a different value than was previously
* set using the {@link #setTrafficClass(int)} method on this Socket.
*
* @return 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.
* @since 1.4
* @see #setTrafficClass(int)
* @see SocketOptions#IP_TOS
*/
public int getTrafficClass() throws SocketException {
return ((Integer) (getImpl().getOption(SocketOptions.IP_TOS))).intValue();
}
/**
* Enable/disable the {@link SocketOptions#SO_REUSEADDR SO_REUSEADDR}
* socket option.
* <p>
* 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 {@code TIME_WAIT} state
* or {@code 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
* {@code SocketAddress} if there is a connection in the
* timeout state involving the socket address or port.
* <p>
* Enabling {@link SocketOptions#SO_REUSEADDR SO_REUSEADDR}
* prior to binding the socket using {@link #bind(SocketAddress)} allows
* the socket to be bound even though a previous connection is in a timeout
* state.
* <p>
* When a {@code Socket} is created the initial setting
* of {@link SocketOptions#SO_REUSEADDR SO_REUSEADDR} is disabled.
* <p>
* The behaviour when {@link SocketOptions#SO_REUSEADDR SO_REUSEADDR} is
* enabled or disabled after a socket is bound (See {@link #isBound()})
* is not defined.
*
* @param on whether to enable or disable the socket option
* @exception SocketException if an error occurs enabling or
* disabling the {@link SocketOptions#SO_REUSEADDR SO_REUSEADDR}
* socket option, or the socket is closed.
* @since 1.4
* @see #getReuseAddress()
* @see #bind(SocketAddress)
* @see #isClosed()
* @see #isBound()
*/
public void setReuseAddress(boolean on) throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.SO_REUSEADDR, Boolean.valueOf(on));
}
/**
* Tests if {@link SocketOptions#SO_REUSEADDR SO_REUSEADDR} is enabled.
*
* @return a {@code boolean} indicating whether or not
* {@link SocketOptions#SO_REUSEADDR SO_REUSEADDR} is enabled.
* @exception SocketException if there is an error
* in the underlying protocol, such as a TCP error.
* @since 1.4
* @see #setReuseAddress(boolean)
*/
public boolean getReuseAddress() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
return ((Boolean) (getImpl().getOption(SocketOptions.SO_REUSEADDR))).booleanValue();
}
/**
* Closes this socket.
* <p>
* Any thread currently blocked in an I/O operation upon this socket
* will throw a {@link SocketException}.
* <p>
* 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.
*
* <p> Closing this socket will also close the socket's
* {@link java.io.InputStream InputStream} and
* {@link java.io.OutputStream OutputStream}.
*
* <p> If this socket has an associated channel then the channel is closed
* as well.
*
* @exception IOException if an I/O error occurs when closing this socket.
* @revised 1.4
* @spec JSR-51
* @see #isClosed
*/
public synchronized void close() throws IOException {
synchronized(closeLock) {
if (isClosed())
return;
if (created)
impl.close();
closed = true;
}
}
/**
* Places the input stream for this socket at "end of stream".
* Any data sent to the input stream side of the socket is acknowledged
* and then silently discarded.
* <p>
* If you read from a socket input stream after invoking this method on the
* socket, the stream's {@code available} method will return 0, and its
* {@code read} methods will return {@code -1} (end of stream).
*
* @exception IOException if an I/O error occurs when shutting down this
* socket.
*
* @since 1.3
* @see java.net.Socket#shutdownOutput()
* @see java.net.Socket#close()
* @see java.net.Socket#setSoLinger(boolean, int)
* @see #isInputShutdown
*/
public void shutdownInput() throws IOException
{
if (isClosed())
throw new SocketException("Socket is closed");
if (!isConnected())
throw new SocketException("Socket is not connected");
if (isInputShutdown())
throw new SocketException("Socket input is already shutdown");
getImpl().shutdownInput();
shutIn = true;
}
/**
* 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.
*
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