Java example source code file (PlainSocketImpl.java)

This example Java source code file (PlainSocketImpl.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

abstractplainsocketimpl, dualstackplainsocketimpl, filedescriptor, inetaddress, inputstream, ioexception, numberformatexception, object, plainsocketimpl, privilegedaction, security, serversocket, socketexception, string, twostacksplainsocketimpl

The PlainSocketImpl.java Java example source code

/*
 * Copyright (c) 2007, 2013, 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.*;
import java.security.PrivilegedAction;

/*
 * This class PlainSocketImpl simply delegates to the appropriate real
 * SocketImpl. We do this because PlainSocketImpl is already extended
 * by SocksSocketImpl.
 * <p>
 * There are two possibilities for the real SocketImpl,
 * TwoStacksPlainSocketImpl or DualStackPlainSocketImpl. We use
 * DualStackPlainSocketImpl on systems that have a dual stack
 * TCP implementation. Otherwise we create an instance of
 * TwoStacksPlainSocketImpl and delegate to it.
 *
 * @author Chris Hegarty
 */

class PlainSocketImpl extends AbstractPlainSocketImpl
{
    private AbstractPlainSocketImpl impl;

    /* the windows version. */
    private static float version;

    /* java.net.preferIPv4Stack */
    private static boolean preferIPv4Stack = false;

    /* If the version supports a dual stack TCP implementation */
    private static boolean useDualStackImpl = false;

    /* sun.net.useExclusiveBind */
    private static String exclBindProp;

    /* True if exclusive binding is on for Windows */
    private static boolean exclusiveBind = true;

    static {
        java.security.AccessController.doPrivileged( new PrivilegedAction<Object>() {
                public Object run() {
                    version = 0;
                    try {
                        version = Float.parseFloat(System.getProperties().getProperty("os.version"));
                        preferIPv4Stack = Boolean.parseBoolean(
                                          System.getProperties().getProperty("java.net.preferIPv4Stack"));
                        exclBindProp = System.getProperty("sun.net.useExclusiveBind");
                    } catch (NumberFormatException e ) {
                        assert false : e;
                    }
                    return null; // nothing to return
                } });

        // (version >= 6.0) implies Vista or greater.
        if (version >= 6.0 && !preferIPv4Stack) {
                useDualStackImpl = true;
        }

        if (exclBindProp != null) {
            // sun.net.useExclusiveBind is true
            exclusiveBind = exclBindProp.length() == 0 ? true
                    : Boolean.parseBoolean(exclBindProp);
        } else if (version < 6.0) {
            exclusiveBind = false;
        }
    }

    /**
     * Constructs an empty instance.
     */
    PlainSocketImpl() {
        if (useDualStackImpl) {
            impl = new DualStackPlainSocketImpl(exclusiveBind);
        } else {
            impl = new TwoStacksPlainSocketImpl(exclusiveBind);
        }
    }

    /**
     * Constructs an instance with the given file descriptor.
     */
    PlainSocketImpl(FileDescriptor fd) {
        if (useDualStackImpl) {
            impl = new DualStackPlainSocketImpl(fd, exclusiveBind);
        } else {
            impl = new TwoStacksPlainSocketImpl(fd, exclusiveBind);
        }
    }

    // Override methods in SocketImpl that access impl's fields.

    protected FileDescriptor getFileDescriptor() {
        return impl.getFileDescriptor();
    }

    protected InetAddress getInetAddress() {
        return impl.getInetAddress();
    }

    protected int getPort() {
        return impl.getPort();
    }

    protected int getLocalPort() {
        return impl.getLocalPort();
    }

    void setSocket(Socket soc) {
        impl.setSocket(soc);
    }

    Socket getSocket() {
        return impl.getSocket();
    }

    void setServerSocket(ServerSocket soc) {
        impl.setServerSocket(soc);
    }

    ServerSocket getServerSocket() {
        return impl.getServerSocket();
    }

    public String toString() {
        return impl.toString();
    }

    // Override methods in AbstractPlainSocketImpl that access impl's fields.

    protected synchronized void create(boolean stream) throws IOException {
        impl.create(stream);

        // set fd to delegate's fd to be compatible with older releases
        this.fd = impl.fd;
    }

    protected void connect(String host, int port)
        throws UnknownHostException, IOException
    {
        impl.connect(host, port);
    }

    protected void connect(InetAddress address, int port) throws IOException {
        impl.connect(address, port);
    }

    protected void connect(SocketAddress address, int timeout) throws IOException {
        impl.connect(address, timeout);
    }

    public void setOption(int opt, Object val) throws SocketException {
        impl.setOption(opt, val);
    }

    public Object getOption(int opt) throws SocketException {
        return impl.getOption(opt);
    }

    synchronized void doConnect(InetAddress address, int port, int timeout) throws IOException {
        impl.doConnect(address, port, timeout);
    }

    protected synchronized void bind(InetAddress address, int lport)
        throws IOException
    {
        impl.bind(address, lport);
    }

    protected synchronized void accept(SocketImpl s) throws IOException {
        if (s instanceof PlainSocketImpl) {
            // pass in the real impl not the wrapper.
            SocketImpl delegate = ((PlainSocketImpl)s).impl;
            delegate.address = new InetAddress();
            delegate.fd = new FileDescriptor();
            impl.accept(delegate);
            // set fd to delegate's fd to be compatible with older releases
            s.fd = delegate.fd;
        } else {
            impl.accept(s);
        }
    }

    void setFileDescriptor(FileDescriptor fd) {
        impl.setFileDescriptor(fd);
    }

    void setAddress(InetAddress address) {
        impl.setAddress(address);
    }

    void setPort(int port) {
        impl.setPort(port);
    }

    void setLocalPort(int localPort) {
        impl.setLocalPort(localPort);
    }

    protected synchronized InputStream getInputStream() throws IOException {
        return impl.getInputStream();
    }

    void setInputStream(SocketInputStream in) {
        impl.setInputStream(in);
    }

    protected synchronized OutputStream getOutputStream() throws IOException {
        return impl.getOutputStream();
    }

    protected void close() throws IOException {
        try {
            impl.close();
        } finally {
            // set fd to delegate's fd to be compatible with older releases
            this.fd = null;
        }
    }

    void reset() throws IOException {
        try {
            impl.reset();
        } finally {
            // set fd to delegate's fd to be compatible with older releases
            this.fd = null;
        }
    }

    protected void shutdownInput() throws IOException {
        impl.shutdownInput();
    }

    protected void shutdownOutput() throws IOException {
        impl.shutdownOutput();
    }

    protected void sendUrgentData(int data) throws IOException {
        impl.sendUrgentData(data);
    }

    FileDescriptor acquireFD() {
        return impl.acquireFD();
    }

    void releaseFD() {
        impl.releaseFD();
    }

    public boolean isConnectionReset() {
        return impl.isConnectionReset();
    }

    public boolean isConnectionResetPending() {
        return impl.isConnectionResetPending();
    }

    public void setConnectionReset() {
        impl.setConnectionReset();
    }

    public void setConnectionResetPending() {
        impl.setConnectionResetPending();
    }

    public boolean isClosedOrPending() {
        return impl.isClosedOrPending();
    }

    public int getTimeout() {
        return impl.getTimeout();
    }

    // Override methods in AbstractPlainSocketImpl that need to be implemented.

    void socketCreate(boolean isServer) throws IOException {
        impl.socketCreate(isServer);
    }

    void socketConnect(InetAddress address, int port, int timeout)
        throws IOException {
        impl.socketConnect(address, port, timeout);
    }

    void socketBind(InetAddress address, int port)
        throws IOException {
        impl.socketBind(address, port);
    }

    void socketListen(int count) throws IOException {
        impl.socketListen(count);
    }

    void socketAccept(SocketImpl s) throws IOException {
        impl.socketAccept(s);
    }

    int socketAvailable() throws IOException {
        return impl.socketAvailable();
    }

    void socketClose0(boolean useDeferredClose) throws IOException {
        impl.socketClose0(useDeferredClose);
    }

    void socketShutdown(int howto) throws IOException {
        impl.socketShutdown(howto);
    }

    void socketSetOption(int cmd, boolean on, Object value)
        throws SocketException {
        impl.socketSetOption(cmd, on, value);
    }

    int socketGetOption(int opt, Object iaContainerObj) throws SocketException {
        return impl.socketGetOption(opt, iaContainerObj);
    }

    void socketSendUrgentData(int data) throws IOException {
        impl.socketSendUrgentData(data);
    }
}