--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/nio/channels/SocketChannel.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,531 @@
+/*
+ * Copyright (c) 2000, 2017, 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.nio.channels;
+
+import java.io.IOException;
+import java.net.Socket;
+import java.net.SocketOption;
+import java.net.SocketAddress;
+import java.nio.ByteBuffer;
+import java.nio.channels.spi.AbstractSelectableChannel;
+import java.nio.channels.spi.SelectorProvider;
+
+/**
+ * A selectable channel for stream-oriented connecting sockets.
+ *
+ * <p> A socket channel is created by invoking one of the {@link #open open}
+ * methods of this class. It is not possible to create a channel for an arbitrary,
+ * pre-existing socket. A newly-created socket channel is open but not yet
+ * connected. An attempt to invoke an I/O operation upon an unconnected
+ * channel will cause a {@link NotYetConnectedException} to be thrown. A
+ * socket channel can be connected by invoking its {@link #connect connect}
+ * method; once connected, a socket channel remains connected until it is
+ * closed. Whether or not a socket channel is connected may be determined by
+ * invoking its {@link #isConnected isConnected} method.
+ *
+ * <p> Socket channels support <i>non-blocking connection:</i> A socket
+ * channel may be created and the process of establishing the link to the
+ * remote socket may be initiated via the {@link #connect connect} method for
+ * later completion by the {@link #finishConnect finishConnect} method.
+ * Whether or not a connection operation is in progress may be determined by
+ * invoking the {@link #isConnectionPending isConnectionPending} method.
+ *
+ * <p> Socket channels support <i>asynchronous shutdown,</i> which is similar
+ * to the asynchronous close operation specified in the {@link Channel} class.
+ * If the input side of a socket is shut down by one thread while another
+ * thread is blocked in a read operation on the socket's channel, then the read
+ * operation in the blocked thread will complete without reading any bytes and
+ * will return {@code -1}. If the output side of a socket is shut down by one
+ * thread while another thread is blocked in a write operation on the socket's
+ * channel, then the blocked thread will receive an {@link
+ * AsynchronousCloseException}.
+ *
+ * <p> Socket options are configured using the {@link #setOption(SocketOption,Object)
+ * setOption} method. Socket channels support the following options:
+ * <blockquote>
+ * <table class="striped">
+ * <caption style="display:none">Socket options</caption>
+ * <thead>
+ * <tr>
+ * <th scope="col">Option Name</th>
+ * <th scope="col">Description</th>
+ * </tr>
+ * </thead>
+ * <tbody>
+ * <tr>
+ * <th scope="row"> {@link java.net.StandardSocketOptions#SO_SNDBUF SO_SNDBUF} </th>
+ * <td> The size of the socket send buffer </td>
+ * </tr>
+ * <tr>
+ * <th scope="row"> {@link java.net.StandardSocketOptions#SO_RCVBUF SO_RCVBUF} </th>
+ * <td> The size of the socket receive buffer </td>
+ * </tr>
+ * <tr>
+ * <th scope="row"> {@link java.net.StandardSocketOptions#SO_KEEPALIVE SO_KEEPALIVE} </th>
+ * <td> Keep connection alive </td>
+ * </tr>
+ * <tr>
+ * <th scope="row"> {@link java.net.StandardSocketOptions#SO_REUSEADDR SO_REUSEADDR} </th>
+ * <td> Re-use address </td>
+ * </tr>
+ * <tr>
+ * <th scope="row"> {@link java.net.StandardSocketOptions#SO_LINGER SO_LINGER} </th>
+ * <td> Linger on close if data is present (when configured in blocking mode
+ * only) </td>
+ * </tr>
+ * <tr>
+ * <th scope="row"> {@link java.net.StandardSocketOptions#TCP_NODELAY TCP_NODELAY} </th>
+ * <td> Disable the Nagle algorithm </td>
+ * </tr>
+ * </tbody>
+ * </table>
+ * </blockquote>
+ * Additional (implementation specific) options may also be supported.
+ *
+ * <p> Socket channels are safe for use by multiple concurrent threads. They
+ * support concurrent reading and writing, though at most one thread may be
+ * reading and at most one thread may be writing at any given time. The {@link
+ * #connect connect} and {@link #finishConnect finishConnect} methods are
+ * mutually synchronized against each other, and an attempt to initiate a read
+ * or write operation while an invocation of one of these methods is in
+ * progress will block until that invocation is complete. </p>
+ *
+ * @author Mark Reinhold
+ * @author JSR-51 Expert Group
+ * @since 1.4
+ */
+
+public abstract class SocketChannel
+ extends AbstractSelectableChannel
+ implements ByteChannel, ScatteringByteChannel, GatheringByteChannel, NetworkChannel
+{
+
+ /**
+ * Initializes a new instance of this class.
+ *
+ * @param provider
+ * The provider that created this channel
+ */
+ protected SocketChannel(SelectorProvider provider) {
+ super(provider);
+ }
+
+ /**
+ * Opens a socket channel.
+ *
+ * <p> The new channel is created by invoking the {@link
+ * java.nio.channels.spi.SelectorProvider#openSocketChannel
+ * openSocketChannel} method of the system-wide default {@link
+ * java.nio.channels.spi.SelectorProvider} object. </p>
+ *
+ * @return A new socket channel
+ *
+ * @throws IOException
+ * If an I/O error occurs
+ */
+ public static SocketChannel open() throws IOException {
+ return SelectorProvider.provider().openSocketChannel();
+ }
+
+ /**
+ * Opens a socket channel and connects it to a remote address.
+ *
+ * <p> This convenience method works as if by invoking the {@link #open()}
+ * method, invoking the {@link #connect(SocketAddress) connect} method upon
+ * the resulting socket channel, passing it {@code remote}, and then
+ * returning that channel. </p>
+ *
+ * @param remote
+ * The remote address to which the new channel is to be connected
+ *
+ * @return A new, and connected, socket channel
+ *
+ * @throws AsynchronousCloseException
+ * If another thread closes this channel
+ * while the connect operation is in progress
+ *
+ * @throws ClosedByInterruptException
+ * If another thread interrupts the current thread
+ * while the connect operation is in progress, thereby
+ * closing the channel and setting the current thread's
+ * interrupt status
+ *
+ * @throws UnresolvedAddressException
+ * If the given remote address is not fully resolved
+ *
+ * @throws UnsupportedAddressTypeException
+ * If the type of the given remote address is not supported
+ *
+ * @throws SecurityException
+ * If a security manager has been installed
+ * and it does not permit access to the given remote endpoint
+ *
+ * @throws IOException
+ * If some other I/O error occurs
+ */
+ public static SocketChannel open(SocketAddress remote)
+ throws IOException
+ {
+ SocketChannel sc = open();
+ try {
+ sc.connect(remote);
+ } catch (Throwable x) {
+ try {
+ sc.close();
+ } catch (Throwable suppressed) {
+ x.addSuppressed(suppressed);
+ }
+ throw x;
+ }
+ assert sc.isConnected();
+ return sc;
+ }
+
+ /**
+ * Returns an operation set identifying this channel's supported
+ * operations.
+ *
+ * <p> Socket channels support connecting, reading, and writing, so this
+ * method returns {@code (}{@link SelectionKey#OP_CONNECT}
+ * {@code |} {@link SelectionKey#OP_READ} {@code |} {@link
+ * SelectionKey#OP_WRITE}{@code )}.
+ *
+ * @return The valid-operation set
+ */
+ public final int validOps() {
+ return (SelectionKey.OP_READ
+ | SelectionKey.OP_WRITE
+ | SelectionKey.OP_CONNECT);
+ }
+
+
+ // -- Socket-specific operations --
+
+ /**
+ * @throws ConnectionPendingException
+ * If a non-blocking connect operation is already in progress on
+ * this channel
+ * @throws AlreadyBoundException {@inheritDoc}
+ * @throws UnsupportedAddressTypeException {@inheritDoc}
+ * @throws ClosedChannelException {@inheritDoc}
+ * @throws IOException {@inheritDoc}
+ * @throws SecurityException
+ * If a security manager has been installed and its
+ * {@link SecurityManager#checkListen checkListen} method denies
+ * the operation
+ *
+ * @since 1.7
+ */
+ @Override
+ public abstract SocketChannel bind(SocketAddress local)
+ throws IOException;
+
+ /**
+ * @throws UnsupportedOperationException {@inheritDoc}
+ * @throws IllegalArgumentException {@inheritDoc}
+ * @throws ClosedChannelException {@inheritDoc}
+ * @throws IOException {@inheritDoc}
+ *
+ * @since 1.7
+ */
+ @Override
+ public abstract <T> SocketChannel setOption(SocketOption<T> name, T value)
+ throws IOException;
+
+ /**
+ * Shutdown the connection for reading without closing the channel.
+ *
+ * <p> Once shutdown for reading then further reads on the channel will
+ * return {@code -1}, the end-of-stream indication. If the input side of the
+ * connection is already shutdown then invoking this method has no effect.
+ *
+ * @return The channel
+ *
+ * @throws NotYetConnectedException
+ * If this channel is not yet connected
+ * @throws ClosedChannelException
+ * If this channel is closed
+ * @throws IOException
+ * If some other I/O error occurs
+ *
+ * @since 1.7
+ */
+ public abstract SocketChannel shutdownInput() throws IOException;
+
+ /**
+ * Shutdown the connection for writing without closing the channel.
+ *
+ * <p> Once shutdown for writing then further attempts to write to the
+ * channel will throw {@link ClosedChannelException}. If the output side of
+ * the connection is already shutdown then invoking this method has no
+ * effect.
+ *
+ * @return The channel
+ *
+ * @throws NotYetConnectedException
+ * If this channel is not yet connected
+ * @throws ClosedChannelException
+ * If this channel is closed
+ * @throws IOException
+ * If some other I/O error occurs
+ *
+ * @since 1.7
+ */
+ public abstract SocketChannel shutdownOutput() throws IOException;
+
+ /**
+ * Retrieves a socket associated with this channel.
+ *
+ * <p> The returned object will not declare any public methods that are not
+ * declared in the {@link java.net.Socket} class. </p>
+ *
+ * @return A socket associated with this channel
+ */
+ public abstract Socket socket();
+
+ /**
+ * Tells whether or not this channel's network socket is connected.
+ *
+ * @return {@code true} if, and only if, this channel's network socket
+ * is {@link #isOpen open} and connected
+ */
+ public abstract boolean isConnected();
+
+ /**
+ * Tells whether or not a connection operation is in progress on this
+ * channel.
+ *
+ * @return {@code true} if, and only if, a connection operation has been
+ * initiated on this channel but not yet completed by invoking the
+ * {@link #finishConnect finishConnect} method
+ */
+ public abstract boolean isConnectionPending();
+
+ /**
+ * Connects this channel's socket.
+ *
+ * <p> If this channel is in non-blocking mode then an invocation of this
+ * method initiates a non-blocking connection operation. If the connection
+ * is established immediately, as can happen with a local connection, then
+ * this method returns {@code true}. Otherwise this method returns
+ * {@code false} and the connection operation must later be completed by
+ * invoking the {@link #finishConnect finishConnect} method.
+ *
+ * <p> If this channel is in blocking mode then an invocation of this
+ * method will block until the connection is established or an I/O error
+ * occurs.
+ *
+ * <p> This method performs exactly the same security checks as the {@link
+ * java.net.Socket} class. That is, if a security manager has been
+ * installed then this method verifies that its {@link
+ * java.lang.SecurityManager#checkConnect checkConnect} method permits
+ * connecting to the address and port number of the given remote endpoint.
+ *
+ * <p> This method may be invoked at any time. If a read or write
+ * operation upon this channel is invoked while an invocation of this
+ * method is in progress then that operation will first block until this
+ * invocation is complete. If a connection attempt is initiated but fails,
+ * that is, if an invocation of this method throws a checked exception,
+ * then the channel will be closed. </p>
+ *
+ * @param remote
+ * The remote address to which this channel is to be connected
+ *
+ * @return {@code true} if a connection was established,
+ * {@code false} if this channel is in non-blocking mode
+ * and the connection operation is in progress
+ *
+ * @throws AlreadyConnectedException
+ * If this channel is already connected
+ *
+ * @throws ConnectionPendingException
+ * If a non-blocking connection operation is already in progress
+ * on this channel
+ *
+ * @throws ClosedChannelException
+ * If this channel is closed
+ *
+ * @throws AsynchronousCloseException
+ * If another thread closes this channel
+ * while the connect operation is in progress
+ *
+ * @throws ClosedByInterruptException
+ * If another thread interrupts the current thread
+ * while the connect operation is in progress, thereby
+ * closing the channel and setting the current thread's
+ * interrupt status
+ *
+ * @throws UnresolvedAddressException
+ * If the given remote address is not fully resolved
+ *
+ * @throws UnsupportedAddressTypeException
+ * If the type of the given remote address is not supported
+ *
+ * @throws SecurityException
+ * If a security manager has been installed
+ * and it does not permit access to the given remote endpoint
+ *
+ * @throws IOException
+ * If some other I/O error occurs
+ */
+ public abstract boolean connect(SocketAddress remote) throws IOException;
+
+ /**
+ * Finishes the process of connecting a socket channel.
+ *
+ * <p> A non-blocking connection operation is initiated by placing a socket
+ * channel in non-blocking mode and then invoking its {@link #connect
+ * connect} method. Once the connection is established, or the attempt has
+ * failed, the socket channel will become connectable and this method may
+ * be invoked to complete the connection sequence. If the connection
+ * operation failed then invoking this method will cause an appropriate
+ * {@link java.io.IOException} to be thrown.
+ *
+ * <p> If this channel is already connected then this method will not block
+ * and will immediately return {@code true}. If this channel is in
+ * non-blocking mode then this method will return {@code false} if the
+ * connection process is not yet complete. If this channel is in blocking
+ * mode then this method will block until the connection either completes
+ * or fails, and will always either return {@code true} or throw a checked
+ * exception describing the failure.
+ *
+ * <p> This method may be invoked at any time. If a read or write
+ * operation upon this channel is invoked while an invocation of this
+ * method is in progress then that operation will first block until this
+ * invocation is complete. If a connection attempt fails, that is, if an
+ * invocation of this method throws a checked exception, then the channel
+ * will be closed. </p>
+ *
+ * @return {@code true} if, and only if, this channel's socket is now
+ * connected
+ *
+ * @throws NoConnectionPendingException
+ * If this channel is not connected and a connection operation
+ * has not been initiated
+ *
+ * @throws ClosedChannelException
+ * If this channel is closed
+ *
+ * @throws AsynchronousCloseException
+ * If another thread closes this channel
+ * while the connect operation is in progress
+ *
+ * @throws ClosedByInterruptException
+ * If another thread interrupts the current thread
+ * while the connect operation is in progress, thereby
+ * closing the channel and setting the current thread's
+ * interrupt status
+ *
+ * @throws IOException
+ * If some other I/O error occurs
+ */
+ public abstract boolean finishConnect() throws IOException;
+
+ /**
+ * Returns the remote address to which this channel's socket is connected.
+ *
+ * <p> Where the channel is bound and connected to an Internet Protocol
+ * socket address then the return value from this method is of type {@link
+ * java.net.InetSocketAddress}.
+ *
+ * @return The remote address; {@code null} if the channel's socket is not
+ * connected
+ *
+ * @throws ClosedChannelException
+ * If the channel is closed
+ * @throws IOException
+ * If an I/O error occurs
+ *
+ * @since 1.7
+ */
+ public abstract SocketAddress getRemoteAddress() throws IOException;
+
+ // -- ByteChannel operations --
+
+ /**
+ * @throws NotYetConnectedException
+ * If this channel is not yet connected
+ */
+ public abstract int read(ByteBuffer dst) throws IOException;
+
+ /**
+ * @throws NotYetConnectedException
+ * If this channel is not yet connected
+ */
+ public abstract long read(ByteBuffer[] dsts, int offset, int length)
+ throws IOException;
+
+ /**
+ * @throws NotYetConnectedException
+ * If this channel is not yet connected
+ */
+ public final long read(ByteBuffer[] dsts) throws IOException {
+ return read(dsts, 0, dsts.length);
+ }
+
+ /**
+ * @throws NotYetConnectedException
+ * If this channel is not yet connected
+ */
+ public abstract int write(ByteBuffer src) throws IOException;
+
+ /**
+ * @throws NotYetConnectedException
+ * If this channel is not yet connected
+ */
+ public abstract long write(ByteBuffer[] srcs, int offset, int length)
+ throws IOException;
+
+ /**
+ * @throws NotYetConnectedException
+ * If this channel is not yet connected
+ */
+ public final long write(ByteBuffer[] srcs) throws IOException {
+ return write(srcs, 0, srcs.length);
+ }
+
+ /**
+ * {@inheritDoc}
+ * <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 java.net.InetAddress#getLoopbackAddress loopback} address and the
+ * local port of the channel's socket is returned.
+ *
+ * @return The {@code SocketAddress} that the socket is bound to, or the
+ * {@code SocketAddress} representing the loopback address if
+ * denied by the security manager, or {@code null} if the
+ * channel's socket is not bound
+ *
+ * @throws ClosedChannelException {@inheritDoc}
+ * @throws IOException {@inheritDoc}
+ */
+ @Override
+ public abstract SocketAddress getLocalAddress() throws IOException;
+
+}