JDK8/Java8源码在线阅读

/*
 * Copyright (c) 2002, 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 com.sun.media.sound;

import java.util.Arrays;

import javax.sound.sampled.*;

/**
 * Class to write an AudioInputStream to a SourceDataLine.
 * Was previously an inner class in various classes like JavaSoundAudioClip
 * and sun.audio.AudioDevice.
 * It auto-opens and closes the SourceDataLine.
 *
 * @author Kara Kytle
 * @author Florian Bomers
 */

public final class DataPusher implements Runnable {

    private static final int AUTO_CLOSE_TIME = 5000;
    private static final boolean DEBUG = false;

    private final SourceDataLine source;
    private final AudioFormat format;

    // stream as source data
    private final AudioInputStream ais;

    // byte array as source data
    private final byte[] audioData;
    private final int audioDataByteLength;
    private int pos;
    private int newPos = -1;
    private boolean looping;

    private Thread pushThread = null;
    private int wantedState;
    private int threadState;

    private final int STATE_NONE = 0;
    private final int STATE_PLAYING = 1;
    private final int STATE_WAITING = 2;
    private final int STATE_STOPPING = 3;
    private final int STATE_STOPPED = 4;
    private final int BUFFER_SIZE = 16384;

    public DataPusher(SourceDataLine sourceLine, AudioFormat format, byte[] audioData, int byteLength) {
        this(sourceLine, format, null, audioData, byteLength);
    }

    public DataPusher(SourceDataLine sourceLine, AudioInputStream ais) {
        this(sourceLine, ais.getFormat(), ais, null, 0);
    }

    private DataPusher(final SourceDataLine source, final AudioFormat format,
                       final AudioInputStream ais, final byte[] audioData,
                       final int audioDataByteLength) {
        this.source = source;
        this.format = format;
        this.ais = ais;
        this.audioDataByteLength = audioDataByteLength;
        this.audioData = audioData == null ? null : Arrays.copyOf(audioData,
                                                                  audioData.length);
    }

    public synchronized void start() {
        start(false);
    }

    public synchronized void start(boolean loop) {
        if (DEBUG || Printer.debug) Printer.debug("> DataPusher.start(loop="+loop+")");
        try {
            if (threadState == STATE_STOPPING) {
                // wait that the thread has finished stopping
                if (DEBUG || Printer.trace)Printer.trace("DataPusher.start(): calling stop()");
                stop();
            }
            looping = loop;
            newPos = 0;
            wantedState = STATE_PLAYING;
            if (!source.isOpen()) {
                if (DEBUG || Printer.trace)Printer.trace("DataPusher: source.open()");
                source.open(format);
            }
            if (DEBUG || Printer.trace)Printer.trace("DataPusher: source.flush()");
            source.flush();
            if (DEBUG || Printer.trace)Printer.trace("DataPusher: source.start()");
            source.start();
            if (pushThread == null) {
                if (DEBUG || Printer.debug) Printer.debug("DataPusher.start(): Starting push");
                pushThread = JSSecurityManager.createThread(this,
                                                            null,   // name
                                                            false,  // daemon
                                                            -1,    // priority
                                                            true); // doStart
            }
            notifyAll();
        } catch (Exception e) {
            if (DEBUG || Printer.err) e.printStackTrace();
        }
        if (DEBUG || Printer.debug) Printer.debug("< DataPusher.start(loop="+loop+")");
    }


    public synchronized void stop() {
        if (DEBUG || Printer.debug) Printer.debug("> DataPusher.stop()");
        if (threadState == STATE_STOPPING
            || threadState == STATE_STOPPED
            || pushThread == null) {
            if (DEBUG || Printer.debug) Printer.debug("DataPusher.stop(): nothing to do");
            return;
        }
        if (DEBUG || Printer.debug) Printer.debug("DataPusher.stop(): Stopping push");

        wantedState = STATE_WAITING;
        if (source != null) {
            if (DEBUG || Printer.trace)Printer.trace("DataPusher: source.flush()");
            source.flush();
        }
        notifyAll();
        int maxWaitCount = 50; // 5 seconds
        while ((maxWaitCount-- >= 0) && (threadState == STATE_PLAYING)) {
            try {
                wait(100);
            } catch (InterruptedException e) {  }
        }
        if (DEBUG || Printer.debug) Printer.debug("< DataPusher.stop()");
    }

    synchronized void close() {
        if (source != null) {
                if (DEBUG || Printer.trace)Printer.trace("DataPusher.close(): source.close()");
                source.close();
        }
    }

    /**
     * Write data to the source data line.
     */
    public void run() {
        byte[] buffer = null;
        boolean useStream = (ais != null);
        if (useStream) {
            buffer = new byte[BUFFER_SIZE];
        } else {
            buffer = audioData;
        }
        while (wantedState != STATE_STOPPING) {
            //try {
                if (wantedState == STATE_WAITING) {
                    // wait for 5 seconds - maybe the clip is to be played again
                    if (DEBUG || Printer.debug)Printer.debug("DataPusher.run(): waiting 5 seconds");
                    try {
                        synchronized(this) {
                                threadState = STATE_WAITING;
                                wantedState = STATE_STOPPING;
                                wait(AUTO_CLOSE_TIME);
                        }
                    } catch (InterruptedException ie) {}
                    if (DEBUG || Printer.debug)Printer.debug("DataPusher.run(): waiting finished");
                    continue;
                }
                if (newPos >= 0) {
                        pos = newPos;
                        newPos = -1;
                }
                threadState = STATE_PLAYING;
                int toWrite = BUFFER_SIZE;
                if (useStream) {
                    try {
                        pos = 0; // always write from beginning of buffer
                        // don't use read(byte[]), because some streams
                        // may not override that method
                        toWrite = ais.read(buffer, 0, buffer.length);
                    } catch (java.io.IOException ioe) {
                        // end of stream
                        toWrite = -1;
                    }
                } else {
                    if (toWrite > audioDataByteLength - pos) {
                        toWrite = audioDataByteLength - pos;
                    }
                    if (toWrite == 0) {
                        toWrite = -1; // end of "stream"
                    }
                }
                if (toWrite < 0) {
                    if (DEBUG || Printer.debug) Printer.debug("DataPusher.run(): Found end of stream");
                        if (!useStream && looping) {
                            if (DEBUG || Printer.debug)Printer.debug("DataPusher.run(): setting pos back to 0");
                            pos = 0;
                            continue;
                        }
                    if (DEBUG || Printer.debug)Printer.debug("DataPusher.run(): calling drain()");
                    wantedState = STATE_WAITING;
                    source.drain();
                    continue;
                }
                if (DEBUG || Printer.debug) Printer.debug("> DataPusher.run(): Writing " + toWrite + " bytes");

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