--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/nio/channels/SocketChannel.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,387 @@
+/*
+ * Copyright 2000-2001 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.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.SocketAddress;
+import java.nio.ByteBuffer;
+import java.nio.channels.spi.*;
+
+
+/**
+ * A selectable channel for stream-oriented connecting sockets.
+ *
+ * <p> Socket channels are not a complete abstraction of connecting network
+ * sockets. Binding, shutdown, and the manipulation of socket options must be
+ * done through an associated {@link java.net.Socket} object obtained by
+ * invoking the {@link #socket() socket} method. It is not possible to create
+ * a channel for an arbitrary, pre-existing socket, nor is it possible to
+ * specify the {@link java.net.SocketImpl} object to be used by a socket
+ * associated with a socket channel.
+ *
+ * <p> A socket channel is created by invoking one of the {@link #open open}
+ * methods of this class. 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> The input and output sides of a socket channel may independently be
+ * <i>shut down</i> without actually closing the channel. Shutting down the
+ * input side of a channel by invoking the {@link java.net.Socket#shutdownInput
+ * shutdownInput} method of an associated socket object will cause further
+ * reads on the channel to return <tt>-1</tt>, the end-of-stream indication.
+ * Shutting down the output side of the channel by invoking the {@link
+ * java.net.Socket#shutdownOutput shutdownOutput} method of an associated
+ * socket object will cause further writes on the channel to throw a {@link
+ * ClosedChannelException}.
+ *
+ * <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 <tt>-1</tt>. 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 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
+{
+
+ /**
+ * Initializes a new instance of this class.
+ */
+ 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 <tt>remote</tt>, and then
+ * returning that channel. </p>
+ *
+ * @param remote
+ * The remote address to which the new channel is to be connected
+ *
+ * @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);
+ } finally {
+ if (!sc.isConnected()) {
+ try { sc.close(); } catch (IOException 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 <tt>(</tt>{@link SelectionKey#OP_CONNECT}
+ * <tt>|</tt> {@link SelectionKey#OP_READ} <tt>|</tt> {@link
+ * SelectionKey#OP_WRITE}<tt>)</tt>. </p>
+ *
+ * @return The valid-operation set
+ */
+ public final int validOps() {
+ return (SelectionKey.OP_READ
+ | SelectionKey.OP_WRITE
+ | SelectionKey.OP_CONNECT);
+ }
+
+
+ // -- Socket-specific operations --
+
+ /**
+ * 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. </p>
+ *
+ * @return <tt>true</tt> if, and only if, this channel's network socket
+ * is connected
+ */
+ public abstract boolean isConnected();
+
+ /**
+ * Tells whether or not a connection operation is in progress on this
+ * channel. </p>
+ *
+ * @return <tt>true</tt> 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 <tt>true</tt>. Otherwise this method returns
+ * <tt>false</tt> 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 <tt>true</tt> if a connection was established,
+ * <tt>false</tt> 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 <tt>true</tt>. If this channel is in
+ * non-blocking mode then this method will return <tt>false</tt> 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 <tt>true</tt> 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 <tt>true</tt> 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;
+
+
+ // -- 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);
+ }
+
+}