/* * Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved. * 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 * or visit www.oracle.com if you need additional information or have any * questions. */ package java.net; import java.io.InputStream; import java.io.OutputStream; import java.io.IOException; import java.io.InterruptedIOException; 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. *

* 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. * * @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. *

* 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: *

* * @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 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); if (p.type() == Proxy.Type.SOCKS) { 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 = new SocksSocketImpl(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. *

* @param impl an instance of a SocketImpl * 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. *

* If the specified host is null it is the equivalent of * specifying the address as {@link java.net.InetAddress#getByName 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. * * @param host the host name, or 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 * 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. *

* 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. * * @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 * 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 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. *

* If the specified host is null it is the equivalent of * specifying the address as {@link java.net.InetAddress#getByName 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. * * @param host the name of the remote host, or null for the loopback address. * @param port the remote port * @param localAddr the local address the socket is bound to, or * null for the anyLocal address. * @param localPort the local port the socket is bound to, or * 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 * checkConnect method doesn't allow the operation. * @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. *

* If the specified local address is null it is the equivalent of * specifying the address as the AnyLocal address (see {@link java.net.InetAddress#isAnyLocalAddress 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. * * @param address the remote address * @param port the remote port * @param localAddr the local address the socket is bound to, or * null for the anyLocal address. * @param localPort the local port the socket is bound to or * 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 * checkConnect method doesn't allow the operation. * @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 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. *

* If the specified host is null it is the equivalent of * specifying the address as {@link java.net.InetAddress#getByName 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. * * @param host the host name, or null for the loopback address. * @param port the port number. * @param stream a 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 * 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. *

* 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. * * @param host the IP address. * @param port the port number. * @param stream if 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 * 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 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); if (address != null) connect(address); } catch (IOException e) { close(); throw e; } } /** * Creates the socket implementation. * * @param stream a boolean value : true for a TCP socket, * 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() { public Boolean run() { Class[] cl = new Class[2]; cl[0] = SocketAddress.class; cl[1] = Integer.TYPE; Class clazz = impl.getClass(); while (true) { try { clazz.getDeclaredMethod("connect", cl); 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 SocketImpl attached to this socket, creating * it if necessary. * * @return the 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 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 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. *

* If the address is null, then the system will pick up * an ephemeral port and a valid local address to bind the socket. * * @param bindpoint the 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 * * @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"); 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. *

* 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 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. * * @return the local address to which the socket is bound, or * the {@link InetAddress#isAnyLocalAddress wildcard} address * if the socket is closed or not bound yet. * @since JDK1.1 */ public InetAddress getLocalAddress() { // This is for backward compatibility if (!isBound()) return InetAddress.anyLocalAddress(); InetAddress in = null; try { in = (InetAddress) getImpl().getOption(SocketOptions.SO_BINDADDR); if (!NetUtil.doRevealLocalAddress()) { 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. *

* 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. *

* 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 * null if it is unconnected. *

* 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 SocketAddress representing the remote endpoint of this * socket, or 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, or * null if it is not bound yet. *

* If a socket bound to an endpoint represented by an * InetSocketAddress is {@link #close 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 * {@link InetAddress#isAnyLocalAddress wildcard} address * and its port is the local port that it was bound to. * * @return a SocketAddress representing the local endpoint of this * socket, or null if it is not bound yet. * @see #getLocalAddress() * @see #getLocalPort() * @see #bind(SocketAddress) * @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. * *

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 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. * *

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 {@link java.nio.channels.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 :- * *

* *

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() { 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. * *

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 {@link * java.nio.channels.IllegalBlockingModeException}. * *

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() { public OutputStream run() throws IOException { return impl.getOutputStream(); } }); } catch (java.security.PrivilegedActionException e) { throw (IOException) e.getException(); } return os; } /** * Enable/disable TCP_NODELAY (disable/enable Nagle's algorithm). * * @param on true to enable TCP_NODELAY, * 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 TCP_NODELAY is enabled. * * @return a boolean indicating whether or not 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 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 SO_LINGER. -1 returns implies that the * option is disabled. * * The setting only affects socket close. * * @return the setting for 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 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. * * @param on true to enable OOBINLINE, * 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 OOBINLINE is enabled. * * @return a boolean indicating whether or not 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 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. * @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 SO_TIMEOUT. 0 returns implies that the * option is disabled (i.e., timeout of infinity). * @return the setting for 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 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 * {@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 SO_SNDBUF option for this Socket, * that is the buffer size used by the platform * for output on this Socket. * @return the value of the SO_SNDBUF option for this 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 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 * {@link #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:

*

    *
  1. 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.

  2. *
  3. For client sockets, setReceiveBufferSize() must be called before * connecting the socket to its remote peer.

* @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 SO_RCVBUF option for this Socket, * that is the buffer size used by the platform for * input on this Socket. * * @return the value of the SO_RCVBUF option for this 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 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 SO_KEEPALIVE is enabled. * * @return a boolean indicating whether or not 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. * *

The tc must be in the range 0 <= tc <= * 255 or an IllegalArgumentException will be thrown. *

Notes: *

For Internet Protocol v4 the value consists of an * 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: *

*

* The last low order bit is always ignored as this * corresponds to the MBZ (must be zero) bit. *

* Setting bits in the precedence field may result in a * SocketException indicating that the operation is not * permitted. *

* 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. *

* For Internet Protocol v6 tc is the value that * would be placed into the sin6_flowinfo field of the IP header. * * @param tc an 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 */ 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 *

* 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) */ public int getTrafficClass() throws SocketException { return ((Integer) (getImpl().getOption(SocketOptions.IP_TOS))).intValue(); } /** * 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 {@link #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 {@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 SO_RESUEADDR 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 SO_REUSEADDR is enabled. * * @return a boolean indicating whether or not 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. *

* Any thread currently blocked in an I/O operation upon this socket * will throw a {@link 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 * {@link java.io.InputStream InputStream} and * {@link java.io.OutputStream OutputStream}. * *

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. *

* If you read from a socket input stream after invoking * shutdownInput() on the socket, the stream will return EOF. * * @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. * * @exception IOException if an I/O error occurs when shutting down this * socket. * * @since 1.3 * @see java.net.Socket#shutdownInput() * @see java.net.Socket#close() * @see java.net.Socket#setSoLinger(boolean, int) * @see #isOutputShutdown */ public void shutdownOutput() 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 already shutdown"); getImpl().shutdownOutput(); shutOut = true; } /** * Converts this socket to a String. * * @return a string representation of this socket. */ public String toString() { try { if (isConnected()) return "Socket[addr=" + getImpl().getInetAddress() + ",port=" + getImpl().getPort() + ",localport=" + getImpl().getLocalPort() + "]"; } catch (SocketException e) { } return "Socket[unconnected]"; } /** * 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 {@link #isClosed()}) if it was successfuly connected prior * to being closed. * * @return true if the socket was successfuly connected to a server * @since 1.4 */ public boolean isConnected() { // Before 1.3 Sockets were always connected during creation return connected || oldImpl; } /** * 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 {@link #isClosed()}) if it was successfuly bound prior * to being closed. * * @return true if the socket was successfuly bound to an address * @since 1.4 * @see #bind */ public boolean isBound() { // Before 1.3 Sockets were always bound during creation return bound || oldImpl; } /** * Returns the closed state of the socket. * * @return true if the socket has been closed * @since 1.4 * @see #close */ public boolean isClosed() { synchronized(closeLock) { return closed; } } /** * Returns whether the read-half of the socket connection is closed. * * @return true if the input of the socket has been shutdown * @since 1.4 * @see #shutdownInput */ public boolean isInputShutdown() { return shutIn; } /** * Returns whether the write-half of the socket connection is closed. * * @return true if the output of the socket has been shutdown * @since 1.4 * @see #shutdownOutput */ public boolean isOutputShutdown() { return shutOut; } /** * The factory for all client sockets. */ private static SocketImplFactory factory = null; /** * Sets the client socket implementation factory for the * application. The factory can be specified only once. *

* When an application creates a new client socket, the socket * implementation factory's createSocketImpl method is * called to create the actual socket implementation. *

* Passing null to the method is a no-op unless the factory * was already set. *

If there is a security manager, this method first calls * the security manager's checkSetFactory method * to ensure the operation is allowed. * This could result in a SecurityException. * * @param fac the desired factory. * @exception IOException if an I/O error occurs when setting the * socket factory. * @exception SocketException if the factory is already defined. * @exception SecurityException if a security manager exists and its * checkSetFactory method doesn't allow the operation. * @see java.net.SocketImplFactory#createSocketImpl() * @see SecurityManager#checkSetFactory */ public static synchronized void setSocketImplFactory(SocketImplFactory fac) throws IOException { if (factory != null) { throw new SocketException("factory already defined"); } SecurityManager security = System.getSecurityManager(); if (security != null) { security.checkSetFactory(); } factory = fac; } /** * 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. * * @param connectionTime * An int expressing the relative importance of a short * connection time * * @param latency * An int expressing the relative importance of low * latency * * @param bandwidth * An int expressing the relative importance of high * bandwidth * * @since 1.5 */ public void setPerformancePreferences(int connectionTime, int latency, int bandwidth) { /* Not implemented yet */ } }