Retry opening track files after failure, and gracefully handle final failure by skipping the track.

src/main/java/moe/nekojimi/chords/MusicHandler.java

@@ -105,6 +105,7 @@ public class MusicHandler implements AudioSendHandler, Closeable, Consumer<Track
         } catch (UnsupportedAudioFileException | IOException ex)
         {
             Logger.getLogger(Chords.class.getName()).log(Level.SEVERE, null, ex);
+            skipTrack();
         } finally
         {
         }

src/main/java/moe/nekojimi/chords/TrackPlayer.java

@@ -8,6 +8,8 @@ package moe.nekojimi.chords;
 import java.io.Closeable;
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import javax.sound.sampled.AudioFormat;
 import javax.sound.sampled.AudioInputStream;
 import javax.sound.sampled.AudioSystem;
@@ -24,6 +26,8 @@ public class TrackPlayer implements Closeable
 
     private static final int DESIRED_BUFFER_SIZE = 3840 * 500;
     private static final int MAX_READ_FAILS = 3;
+    private static final int RETRY_COUNT = 10;
+    private static final int RETRY_DELAY = 100;
 
     private final CircularByteBuffer audioBuffer = new CircularByteBuffer(3840 * 1024);
 
@@ -33,8 +37,34 @@ public class TrackPlayer implements Closeable
 
     public TrackPlayer(Track track) throws UnsupportedAudioFileException, IOException
     {
-        AudioInputStream in = AudioSystem.getAudioInputStream(track.getLocation());
-        AudioFormat decodedFormat = AudioSendHandler.INPUT_FORMAT;
+        AudioInputStream in = null;
+        AudioFormat decodedFormat = null;
+        for (int retry = 0; retry < RETRY_COUNT; retry++)
+        {
+            try
+            {
+                in = AudioSystem.getAudioInputStream(track.getLocation());
+                decodedFormat = AudioSendHandler.INPUT_FORMAT;
+
+                break; // it worked!
+            } catch (IOException ex)
+            {
+                try
+                {
+                    Thread.sleep(((long) Math.pow(2, retry)) * RETRY_DELAY);
+                } catch (InterruptedException ex1)
+                {
+                    if (retry < RETRY_COUNT)
+                    {
+                        System.err.println("Open file " + track.getLocation() + " failed, retry " + retry + "...");
+                        continue;
+                    } else
+                    {
+                        throw ex;
+                    }
+                }
+            }
+        }
         input = AudioSystem.getAudioInputStream(decodedFormat, in);
         fillBuffer(false);
     }