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Mihály Kuprivecz
2017-04-06 23:48:15 +02:00
parent 073d06c0ae
commit dce767c1c5
8 changed files with 277 additions and 0 deletions
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67
event-queue/src/main/java/com/iluwatar/event/queue/App.java Normal file
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/**
* The MIT License
* Copyright (c) 2014-2016 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.event.queue;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.UnsupportedAudioFileException;
/**
* Event or message queues provide an asynchronous communications protocol, meaning that the sender
* and receiver of the message do not need to interact with the message queue at the same time.
* Events or messages placed onto the queue are stored until the recipient retrieves them. Event
* or message queues have implicit or explicit limits on the size of data that may be transmitted
* in a single message and the number of messages that may remain outstanding on the queue.
* A queue stores a series of notifications or requests in first-in, first-out order.
* Sending a notification enqueues the request and returns. The request processor then processes
* items from the queue at a later time.
*/
public class App {
/**
* Program entry point.
*
* @param args command line args
* @throws IOException when there is a problem with the audio file loading
* @throws UnsupportedAudioFileException when the loaded audio file is unsupported
*/
public static void main(String[] args) throws UnsupportedAudioFileException, IOException {
Audio.playSound(getAudioStream("./etc/Bass-Drum-1.wav"), -10.0f);
Audio.playSound(getAudioStream("./etc/Closed-Hi-Hat-1.wav"), -8.0f);
System.out.println("Press Enter key to stop the program...");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
br.read();
Audio.stopService();
}
public static AudioInputStream getAudioStream(String filePath)
throws UnsupportedAudioFileException, IOException {
return AudioSystem.getAudioInputStream(new File(filePath).getAbsoluteFile());
}
}

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event-queue/src/main/java/com/iluwatar/event/queue/Audio.java Normal file
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/**
* The MIT License
* Copyright (c) 2014-2016 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.event.queue;
import java.io.IOException;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.sound.sampled.LineUnavailableException;
/**
* This class implements the Event Queue pattern.
* @author mkuprivecz
*
*/
public class Audio {
private static final int MAX_PENDING = 16;
private static int headIndex;
private static int tailIndex;
private static Thread updateThread = null;
private static PlayMessage[] pendingAudio = new PlayMessage[MAX_PENDING];
public static boolean isServiceRunning() {
return updateThread.isAlive();
}
/**
* This method stops the Update Method's thread.
*/
public static void stopService() {
if (updateThread != null) {
updateThread.interrupt();
}
}
/**
* Starts the thread for the Update Method pattern if it was not started previously.
* Also when the thread is is ready initializes the indexes of the queue
*/
public static void init() {
if (updateThread == null) {
updateThread = new Thread(new Runnable() {
public void run() {
while (!Thread.currentThread().isInterrupted()) {
Audio.update();
}
}
});
}
if (!updateThread.isAlive()) {
updateThread.start();
headIndex = 0;
tailIndex = 0;
}
}
/**
* This method adds a new audio into the queue.
* @param stream is the AudioInputStream for the method
* @param volume is the level of the audio's volume
*/
public static void playSound(AudioInputStream stream, float volume) {
init();
// Walk the pending requests.
for (int i = headIndex; i != tailIndex; i = (i + 1) % MAX_PENDING) {
if (pendingAudio[i].stream == stream) {
// Use the larger of the two volumes.
pendingAudio[i].volume = Math.max(volume, pendingAudio[i].volume);
// Don't need to enqueue.
return;
}
}
pendingAudio[tailIndex] = new PlayMessage();
pendingAudio[tailIndex].stream = stream;
pendingAudio[tailIndex].volume = volume;
tailIndex = (tailIndex + 1) % MAX_PENDING;
}
/**
* This method uses the Update Method pattern.
* It takes the audio from the queue and plays it
*/
public static void update() {
// If there are no pending requests, do nothing.
if (headIndex == tailIndex) {
return;
}
Clip clip = null;
try {
clip = AudioSystem.getClip();
clip.open(pendingAudio[headIndex].stream);
} catch (LineUnavailableException e) {
System.err.println("Error occoured while loading the audio: The line is unavailable");
e.printStackTrace();
} catch (IOException e) {
System.err.println("Input/Output error while loading the audio");
e.printStackTrace();
}
clip.start();
headIndex++;
}
}

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event-queue/src/main/java/com/iluwatar/event/queue/PlayMessage.java Normal file
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/**
* The MIT License
* Copyright (c) 2014-2016 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.event.queue;
import javax.sound.sampled.AudioInputStream;
/**
* The Event Queue's queue will store the instances of this class.
* @author mkuprivecz
*
*/
public class PlayMessage {
AudioInputStream stream;
float volume;
}