Java Question Audio Streamer with progress bar Library Question

package bayalu.audio.stream;

import anywheresoftware.b4a.BA;
import anywheresoftware.b4a.BA.ShortName;
import anywheresoftware.b4a.BA.Author;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import android.content.Context;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Handler;
import android.util.Log;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;

@ShortName("AudioStreamer")
@Author("SK")
public class AudioStream {

/**
* MediaPlayer does not yet support streaming from external URLs so this class provides a pseudo-streaming function
* by downloading the content incrementally & playing as soon as we get enough audio in our temporary storage.
*/


    private static final int INTIAL_KB_BUFFER =  96*10/8;//assume 96kbps*10secs/8bits per byte

    private TextView textStreamed;
   
    private Button playButton;
   
    private ProgressBar    progressBar;
   
    //  Track for display by progressBar
    private long mediaLengthInKb, mediaLengthInSeconds;
    private int totalKbRead = 0;
   
    // Create Handler to call View updates on the main UI thread.
    private final Handler handler = new Handler();

    private MediaPlayer mediaPlayer ;
   
    private File downloadingMediaFile;
   
    private boolean isInterrupted;
   
    private Context context;
   
    private int counter = 0;
   
    public void StreamingMediaPlayer(BA ba,TextView textStreamed, Button playButton, Button    streamButton,ProgressBar progressBar)
    {
        this.context = ba.context ;
        this.textStreamed = textStreamed;
        this.playButton = playButton;
        this.progressBar = progressBar;
    }
   
    /** 
    * Progressivly download the media to a temporary location and update the MediaPlayer as new content becomes available.
    */ 
    public void startStreaming(final String mediaUrl, long    mediaLengthInKb, long    mediaLengthInSeconds) throws IOException {
       
        this.mediaLengthInKb = mediaLengthInKb;
        this.mediaLengthInSeconds = mediaLengthInSeconds;
       
        Runnable r = new Runnable() { 
            public void run() { 
                try { 
                    downloadAudioIncrement(mediaUrl);
                } catch (IOException e) {
                    Log.e(getClass().getName(), "Unable to initialize the MediaPlayer for fileUrl=" + mediaUrl, e);
                    return;
                } 
            } 
        }; 
        new Thread(r).start();
    }
   
    /** 
    * Download the url stream to a temporary location and then call the setDataSource 
    * for that local file
    */ 
    public void downloadAudioIncrement(String mediaUrl) throws IOException {
       
        URLConnection cn = new URL(mediaUrl).openConnection(); 
        cn.connect(); 
        InputStream stream = cn.getInputStream();
        if (stream == null) {
            Log.e(getClass().getName(), "Unable to create InputStream for mediaUrl:" + mediaUrl);
        }
       
        downloadingMediaFile = new File(context.getCacheDir(),"downloadingMedia_" + (counter++) + ".dat");
        FileOutputStream out = new FileOutputStream(downloadingMediaFile); 
        byte buf[] = new byte[16384];
        int totalBytesRead = 0, incrementalBytesRead = 0;
        do {
            int numread = stream.read(buf); 
            if (numread <= 0) 
                break; 
            out.write(buf, 0, numread);
            totalBytesRead += numread;
            incrementalBytesRead += numread;
            totalKbRead = totalBytesRead/1000;
           
            testMediaBuffer();
              fireDataLoadUpdate();
        } while (validateNotInterrupted()); 

          stream.close();
        if (validateNotInterrupted()) {
              fireDataFullyLoaded();
        }
    } 

    public void PausePlaying()
    {
        if( mediaPlayer.isPlaying() == true)
        {
            mediaPlayer.pause();
        }
    }
   
    public void StopPlaying()
    {
        if( mediaPlayer.isPlaying() == true)
        {
            mediaPlayer.stop();
        }
    }
       
    public void StartPlaying ()
    {
        mediaPlayer.start();
    }
 
    private boolean validateNotInterrupted() {
        if (isInterrupted) {
            if (mediaPlayer != null) {
                mediaPlayer.pause();
                //mediaPlayer.release();
            }
            return false;
        } else {
            return true;
        }
    }

   
    /**
    * Test whether we need to transfer buffered data to the MediaPlayer.
    * Interacting with MediaPlayer on non-main UI thread can causes crashes to so perform this using a Handler.
    */ 
    private void  testMediaBuffer() {
        Runnable updater = new Runnable() {
            public void run() {
                if (mediaPlayer == null) {
                    //  Only create the MediaPlayer once we have the minimum buffered data
                    if ( totalKbRead >= INTIAL_KB_BUFFER) {
                        try {
                            startMediaPlayer();
                        } catch (Exception e) {
                            Log.e(getClass().getName(), "Error copying buffered conent.", e);               
                        }
                    }
                } else if ( mediaPlayer.getDuration() - mediaPlayer.getCurrentPosition() <= 1000 ){
                    //  NOTE:  The media player has stopped at the end so transfer any existing buffered data
                    //  We test for < 1second of data because the media player can stop when there is still
                    //  a few milliseconds of data left to play
                    transferBufferToMediaPlayer();
                }
            }
        };
        handler.post(updater);
    }
   
    private void startMediaPlayer() {
        try { 
            File bufferedFile = new File(context.getCacheDir(),"playingMedia" + (counter++) + ".dat");
            moveFile(downloadingMediaFile,bufferedFile);
           
            Log.e("Player",bufferedFile.length()+"");
            Log.e("Player",bufferedFile.getAbsolutePath());
           
            mediaPlayer = new MediaPlayer();
            mediaPlayer.setDataSource(bufferedFile.getAbsolutePath());
            mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
            mediaPlayer.prepare();
            fireDataPreloadComplete();
           
        } catch (IOException e) {
            Log.e(getClass().getName(), "Error initializing the MediaPlaer.", e);
            return;
        } 
    }
   
    /**
    * Transfer buffered data to the MediaPlayer.
    * Interacting with MediaPlayer on non-main UI thread can causes crashes to so perform this using a Handler.
    */ 
    private void transferBufferToMediaPlayer() {
        try {
            // First determine if we need to restart the player after transferring data...e.g. perhaps the user pressed pause
            boolean wasPlaying = mediaPlayer.isPlaying();
            int curPosition = mediaPlayer.getCurrentPosition();
            mediaPlayer.pause();

            File bufferedFile = new File(context.getCacheDir(),"playingMedia" + (counter++) + ".dat");
            //FileUtils.copyFile(downloadingMediaFile,bufferedFile);

            mediaPlayer = new MediaPlayer();
            mediaPlayer.setDataSource(bufferedFile.getAbsolutePath());
            //mediaPlayer.setAudioStreamType(AudioSystem.STREAM_MUSIC);
            mediaPlayer.prepare();
            mediaPlayer.seekTo(curPosition);
           
            //  Restart if at end of prior beuffered content or mediaPlayer was previously playing. 
            //    NOTE:  We test for < 1second of data because the media player can stop when there is still
            //  a few milliseconds of data left to play
            boolean atEndOfFile = mediaPlayer.getDuration() - mediaPlayer.getCurrentPosition() <= 1000;
            if (wasPlaying || atEndOfFile){
                mediaPlayer.start();
            }
        }catch (Exception e) {
            Log.e(getClass().getName(), "Error updating to newly loaded content.", e);                   
        }
    }
   
    private void fireDataLoadUpdate() {
        Runnable updater = new Runnable() {
            public void run() {
                textStreamed.setText((CharSequence) (totalKbRead + " Kb read"));
                float loadProgress = ((float)totalKbRead/(float)mediaLengthInKb);
                progressBar.setSecondaryProgress((int)(loadProgress*100));
            }
        };
        handler.post(updater);
    }
   
    /**
    * We have preloaded enough content and started the MediaPlayer so update the buttons & progress meters.
    */
    private void fireDataPreloadComplete() {
        Runnable updater = new Runnable() {
            public void run() {
                mediaPlayer.start();
                startPlayProgressUpdater();
                playButton.setEnabled(true);
                //streamButton.setEnabled(false);
            }
        };
        handler.post(updater);
    }

    private void fireDataFullyLoaded() {
        Runnable updater = new Runnable() {
            public void run() {
                  transferBufferToMediaPlayer();
                textStreamed.setText((CharSequence) ("Audio full loaded: " + totalKbRead + " Kb read"));
            }
        };
        handler.post(updater);
    }
   
    public MediaPlayer getMediaPlayer() {
        return mediaPlayer;
    }
   
    public void startPlayProgressUpdater() {
        float progress = (((float)mediaPlayer.getCurrentPosition()/1000)/(float)mediaLengthInSeconds);
        progressBar.setProgress((int)(progress*100));
       
        if (mediaPlayer.isPlaying()) {
            Runnable notification = new Runnable() {
                public void run() {
                    startPlayProgressUpdater();
                }
            };
            handler.postDelayed(notification,1000);
        }
    }   
   
  /* private void interrupt() {
        playButton.setEnabled(false);
        isInterrupted = true;
        validateNotInterrupted();
    }*/
   
    public void moveFile(File    oldLocation, File    newLocation)
    throws IOException {

        if ( oldLocation.exists( )) {
            BufferedInputStream  reader = new BufferedInputStream( new FileInputStream(oldLocation) );
            BufferedOutputStream  writer = new BufferedOutputStream( new FileOutputStream(newLocation, false));
            try {
                byte[]  buff = new byte[8192];
                int numChars;
                while ( (numChars = reader.read(  buff, 0, buff.length ) ) != -1) {
                    writer.write( buff, 0, numChars );
                  }
            } catch( IOException ex ) {
                throw new IOException("IOException when transferring " + oldLocation.getPath() + " to " + newLocation.getPath());
            } finally {
                try {
                    if ( reader != null ){
                        writer.close();
                        reader.close();
                    }
                } catch( IOException ex ){
                    Log.e(getClass().getName(),"Error closing files when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() );
                }
            }
        } else {
            throw new IOException("Old location does not exist when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() );
        }
    }
}