Aufzeichnen von Audio -, speichern in .wav-Datei-format in android

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;

import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

    private static final int RECORDER_BPP = 16;
    private static final String AUDIO_RECORDER_FILE_EXT_WAV = ".wav";
    private static final String AUDIO_RECORDER_FOLDER = "AudioRecorder";
    private static final String AUDIO_RECORDER_TEMP_FILE = "record_temp.raw";
    private static final int RECORDER_SAMPLERATE = 44100;
    private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_STEREO;
    private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;
    short[] audioData;

    private AudioRecord recorder = null;
    private int bufferSize = 0;
    private Thread recordingThread = null;
    private boolean isRecording = false;
    Complex[] fftTempArray;
    Complex[] fftArray;
    int[] bufferData;
    int bytesRecorded;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setButtonHandlers();
        enableButtons(false);

        bufferSize = AudioRecord.getMinBufferSize
              (RECORDER_SAMPLERATE,RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING)*3;

        audioData = new short [bufferSize]; //short array that pcm data is put into.
    }

    private void setButtonHandlers() {
        ((Button)findViewById(R.id.btnStart)).setOnClickListener(btnClick);
        ((Button)findViewById(R.id.btnStop)).setOnClickListener(btnClick);
    }


    private void enableButton(int id,boolean isEnable){
        ((Button)findViewById(id)).setEnabled(isEnable);
    }

    private void enableButtons(boolean isRecording) {
        enableButton(R.id.btnStart,!isRecording);
        enableButton(R.id.btnStop,isRecording);
    }

    private String getFilename(){
        String filepath = Environment.getExternalStorageDirectory().getPath();
        File file = new File(filepath,AUDIO_RECORDER_FOLDER);

        if (!file.exists()) {
            file.mkdirs();
        }

        return (file.getAbsolutePath() + "/" + System.currentTimeMillis() +
             AUDIO_RECORDER_FILE_EXT_WAV);
    }

    private String getTempFilename() {
        String filepath = Environment.getExternalStorageDirectory().getPath();
        File file = new File(filepath,AUDIO_RECORDER_FOLDER);

        if (!file.exists()) {
            file.mkdirs();
        }

        File tempFile = new File(filepath,AUDIO_RECORDER_TEMP_FILE);

        if (tempFile.exists())
            tempFile.delete();

        return (file.getAbsolutePath() + "/" + AUDIO_RECORDER_TEMP_FILE);
    }

    private void startRecording() {
        recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,
                                   RECORDER_SAMPLERATE,
                                   RECORDER_CHANNELS,
                                   RECORDER_AUDIO_ENCODING,
                                   bufferSize);
        int i = recorder.getState();
        if (i==1)
            recorder.startRecording();

        isRecording = true;

        recordingThread = new Thread(new Runnable() {
            @Override
            public void run() {
                writeAudioDataToFile();
            }
         }, "AudioRecorder Thread");

        recordingThread.start();
    }

    private void writeAudioDataToFile() {
        byte data[] = new byte[bufferSize];
        String filename = getTempFilename();
        FileOutputStream os = null;

        try {
            os = new FileOutputStream(filename);
        } catch (FileNotFoundException e) {
            //TODO Auto-generated catch block
            e.printStackTrace();
        }

        int read = 0;
        if (null != os) {
            while(isRecording) {
                read = recorder.read(data, 0, bufferSize);
                if (read > 0){
                }

                if (AudioRecord.ERROR_INVALID_OPERATION != read) {
                    try {
                        os.write(data);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }

            try {
                os.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    private void stopRecording() {
        if (null != recorder){
            isRecording = false;

            int i = recorder.getState();
            if (i==1)
                recorder.stop();
            recorder.release();

            recorder = null;
            recordingThread = null;
        }

        copyWaveFile(getTempFilename(),getFilename());
        deleteTempFile();
    }

    private void deleteTempFile() {
        File file = new File(getTempFilename());
        file.delete();
     }

     private void copyWaveFile(String inFilename,String outFilename){
         FileInputStream in = null;
         FileOutputStream out = null;
         long totalAudioLen = 0;
         long totalDataLen = totalAudioLen + 36;
         long longSampleRate = RECORDER_SAMPLERATE;
         int channels = 2;
         long byteRate = RECORDER_BPP * RECORDER_SAMPLERATE * channels/8;

         byte[] data = new byte[bufferSize];

         try {
             in = new FileInputStream(inFilename);
             out = new FileOutputStream(outFilename);
             totalAudioLen = in.getChannel().size();
             totalDataLen = totalAudioLen + 36;

             AppLog.logString("File size: " + totalDataLen);

             WriteWaveFileHeader(out, totalAudioLen, totalDataLen,
                          longSampleRate, channels, byteRate);

             while(in.read(data) != -1) {
                 out.write(data);
             }

             in.close();
             out.close();
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }
     }

     private void WriteWaveFileHeader(
         FileOutputStream out, long totalAudioLen,
         long totalDataLen, long longSampleRate, int channels,
         long byteRate) throws IOException
     {
         byte[] header = new byte[44];

         header[0] = 'R';  //RIFF/WAVE header
         header[1] = 'I';
         header[2] = 'F';
         header[3] = 'F';
         header[4] = (byte) (totalDataLen & 0xff);
         header[5] = (byte) ((totalDataLen >> 8) & 0xff);
         header[6] = (byte) ((totalDataLen >> 16) & 0xff);
         header[7] = (byte) ((totalDataLen >> 24) & 0xff);
         header[8] = 'W';
         header[9] = 'A';
         header[10] = 'V';
         header[11] = 'E';
         header[12] = 'f';  //'fmt ' chunk
         header[13] = 'm';
         header[14] = 't';
         header[15] = ' ';
         header[16] = 16;  //4 bytes: size of 'fmt ' chunk
         header[17] = 0;
         header[18] = 0;
         header[19] = 0;
         header[20] = 1;  //format = 1
         header[21] = 0;
         header[22] = (byte) channels;
         header[23] = 0;
         header[24] = (byte) (longSampleRate & 0xff);
         header[25] = (byte) ((longSampleRate >> 8) & 0xff);
         header[26] = (byte) ((longSampleRate >> 16) & 0xff);
         header[27] = (byte) ((longSampleRate >> 24) & 0xff);
         header[28] = (byte) (byteRate & 0xff);
         header[29] = (byte) ((byteRate >> 8) & 0xff);
         header[30] = (byte) ((byteRate >> 16) & 0xff);
         header[31] = (byte) ((byteRate >> 24) & 0xff);
         header[32] = (byte) (2 * 16 / 8);  //block align
         header[33] = 0;
         header[34] = RECORDER_BPP;  //bits per sample
         header[35] = 0;
         header[36] = 'd';
         header[37] = 'a';
         header[38] = 't';
         header[39] = 'a';
         header[40] = (byte) (totalAudioLen & 0xff);
         header[41] = (byte) ((totalAudioLen >> 8) & 0xff);
         header[42] = (byte) ((totalAudioLen >> 16) & 0xff);
         header[43] = (byte) ((totalAudioLen >> 24) & 0xff);

         out.write(header, 0, 44);
     }

     private View.OnClickListener btnClick = new View.OnClickListener() {
         @Override
         public void onClick(View v) {
             switch(v.getId()){
                 case R.id.btnStart:{
                     AppLog.logString("Start Recording");

                     enableButtons(true);
                     startRecording();

                     break;
                 }
                 case R.id.btnStop:{
                     AppLog.logString("Start Recording");

                     enableButtons(false);
                     stopRecording();

                     break;
                 }
             }
         }
     };
}

Ich bin neu auf android.Ich habe diesen code zum speichern der aufgezeichneten audio-in .wav-format, aber AudioRecorder Ordner verwiesen wird in diesem code nicht erstellt. Ich will speichern, die audio .wav-Datei auf dem internen Speicher.