src/java.base/share/classes/java/nio/channels/ServerSocketChannel.java
changeset 47216 71c04702a3d5
parent 45881 aaec0fbe17ae
child 58801 119ac9128c1b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/nio/channels/ServerSocketChannel.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,297 @@
+/*
+ * 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.ServerSocket;
+import java.net.SocketOption;
+import java.net.SocketAddress;
+import java.nio.channels.spi.AbstractSelectableChannel;
+import java.nio.channels.spi.SelectorProvider;
+
+/**
+ * A selectable channel for stream-oriented listening sockets.
+ *
+ * <p> A server-socket channel is created by invoking the {@link #open() open}
+ * method of this class.  It is not possible to create a channel for an arbitrary,
+ * pre-existing {@link ServerSocket}. A newly-created server-socket channel is
+ * open but not yet bound.  An attempt to invoke the {@link #accept() accept}
+ * method of an unbound server-socket channel will cause a {@link NotYetBoundException}
+ * to be thrown. A server-socket channel can be bound by invoking one of the
+ * {@link #bind(java.net.SocketAddress,int) bind} methods defined by this class.
+ *
+ * <p> Socket options are configured using the {@link #setOption(SocketOption,Object)
+ * setOption} method. Server-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_RCVBUF SO_RCVBUF} </th>
+ *     <td> The size of the socket receive buffer </td>
+ *   </tr>
+ *   <tr>
+ *     <th scope="row"> {@link java.net.StandardSocketOptions#SO_REUSEADDR SO_REUSEADDR} </th>
+ *     <td> Re-use address </td>
+ *   </tr>
+ * </tbody>
+ * </table>
+ * </blockquote>
+ * Additional (implementation specific) options may also be supported.
+ *
+ * <p> Server-socket channels are safe for use by multiple concurrent threads.
+ * </p>
+ *
+ * @author Mark Reinhold
+ * @author JSR-51 Expert Group
+ * @since 1.4
+ */
+
+public abstract class ServerSocketChannel
+    extends AbstractSelectableChannel
+    implements NetworkChannel
+{
+
+    /**
+     * Initializes a new instance of this class.
+     *
+     * @param  provider
+     *         The provider that created this channel
+     */
+    protected ServerSocketChannel(SelectorProvider provider) {
+        super(provider);
+    }
+
+    /**
+     * Opens a server-socket channel.
+     *
+     * <p> The new channel is created by invoking the {@link
+     * java.nio.channels.spi.SelectorProvider#openServerSocketChannel
+     * openServerSocketChannel} method of the system-wide default {@link
+     * java.nio.channels.spi.SelectorProvider} object.
+     *
+     * <p> The new channel's socket is initially unbound; it must be bound to a
+     * specific address via one of its socket's {@link
+     * java.net.ServerSocket#bind(SocketAddress) bind} methods before
+     * connections can be accepted.  </p>
+     *
+     * @return  A new socket channel
+     *
+     * @throws  IOException
+     *          If an I/O error occurs
+     */
+    public static ServerSocketChannel open() throws IOException {
+        return SelectorProvider.provider().openServerSocketChannel();
+    }
+
+    /**
+     * Returns an operation set identifying this channel's supported
+     * operations.
+     *
+     * <p> Server-socket channels only support the accepting of new
+     * connections, so this method returns {@link SelectionKey#OP_ACCEPT}.
+     * </p>
+     *
+     * @return  The valid-operation set
+     */
+    public final int validOps() {
+        return SelectionKey.OP_ACCEPT;
+    }
+
+
+    // -- ServerSocket-specific operations --
+
+    /**
+     * Binds the channel's socket to a local address and configures the socket
+     * to listen for connections.
+     *
+     * <p> An invocation of this method is equivalent to the following:
+     * <blockquote><pre>
+     * bind(local, 0);
+     * </pre></blockquote>
+     *
+     * @param   local
+     *          The local address to bind the socket, or {@code null} to bind
+     *          to an automatically assigned socket address
+     *
+     * @return  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
+     */
+    public final ServerSocketChannel bind(SocketAddress local)
+        throws IOException
+    {
+        return bind(local, 0);
+    }
+
+    /**
+     * Binds the channel's socket to a local address and configures the socket to
+     * listen for connections.
+     *
+     * <p> This method is used to establish an association between the socket and
+     * a local address. Once an association is established then the socket remains
+     * bound until the channel is closed.
+     *
+     * <p> The {@code backlog} parameter is the maximum number of pending
+     * connections on the socket. Its exact semantics are implementation specific.
+     * In particular, an implementation may impose a maximum length or may choose
+     * to ignore the parameter altogther. If the {@code backlog} parameter has
+     * the value {@code 0}, or a negative value, then an implementation specific
+     * default is used.
+     *
+     * @param   local
+     *          The address to bind the socket, or {@code null} to bind to an
+     *          automatically assigned socket address
+     * @param   backlog
+     *          The maximum number of pending connections
+     *
+     * @return  This channel
+     *
+     * @throws  AlreadyBoundException
+     *          If the socket is already bound
+     * @throws  UnsupportedAddressTypeException
+     *          If the type of the given address is not supported
+     * @throws  ClosedChannelException
+     *          If this channel is closed
+     * @throws  IOException
+     *          If some other I/O error occurs
+     * @throws  SecurityException
+     *          If a security manager has been installed and its {@link
+     *          SecurityManager#checkListen checkListen} method denies the
+     *          operation
+     *
+     * @since 1.7
+     */
+    public abstract ServerSocketChannel bind(SocketAddress local, int backlog)
+        throws IOException;
+
+    /**
+     * @throws  UnsupportedOperationException           {@inheritDoc}
+     * @throws  IllegalArgumentException                {@inheritDoc}
+     * @throws  ClosedChannelException                  {@inheritDoc}
+     * @throws  IOException                             {@inheritDoc}
+     *
+     * @since 1.7
+     */
+    public abstract <T> ServerSocketChannel setOption(SocketOption<T> name, T value)
+        throws IOException;
+
+    /**
+     * Retrieves a server socket associated with this channel.
+     *
+     * <p> The returned object will not declare any public methods that are not
+     * declared in the {@link java.net.ServerSocket} class.  </p>
+     *
+     * @return  A server socket associated with this channel
+     */
+    public abstract ServerSocket socket();
+
+    /**
+     * Accepts a connection made to this channel's socket.
+     *
+     * <p> If this channel is in non-blocking mode then this method will
+     * immediately return {@code null} if there are no pending connections.
+     * Otherwise it will block indefinitely until a new connection is available
+     * or an I/O error occurs.
+     *
+     * <p> The socket channel returned by this method, if any, will be in
+     * blocking mode regardless of the blocking mode of this channel.
+     *
+     * <p> This method performs exactly the same security checks as the {@link
+     * java.net.ServerSocket#accept accept} method of the {@link
+     * java.net.ServerSocket} class.  That is, if a security manager has been
+     * installed then for each new connection this method verifies that the
+     * address and port number of the connection's remote endpoint are
+     * permitted by the security manager's {@link
+     * java.lang.SecurityManager#checkAccept checkAccept} method.  </p>
+     *
+     * @return  The socket channel for the new connection,
+     *          or {@code null} if this channel is in non-blocking mode
+     *          and no connection is available to be accepted
+     *
+     * @throws  ClosedChannelException
+     *          If this channel is closed
+     *
+     * @throws  AsynchronousCloseException
+     *          If another thread closes this channel
+     *          while the accept operation is in progress
+     *
+     * @throws  ClosedByInterruptException
+     *          If another thread interrupts the current thread
+     *          while the accept operation is in progress, thereby
+     *          closing the channel and setting the current thread's
+     *          interrupt status
+     *
+     * @throws  NotYetBoundException
+     *          If this channel's socket has not yet been bound
+     *
+     * @throws  SecurityException
+     *          If a security manager has been installed
+     *          and it does not permit access to the remote endpoint
+     *          of the new connection
+     *
+     * @throws  IOException
+     *          If some other I/O error occurs
+     */
+    public abstract SocketChannel accept() throws IOException;
+
+    /**
+     * {@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;
+
+}