public class Audio_Record extends Activity {private static final int RECORDER_SAMPLERATE = 8000;private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_MONO;private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;private AudioRecord recorder = null;private Thread recordingThread = null;private boolean isRecording = false;@Overridepublic void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.main);    setButtonHandlers();    enableButtons(false);    int bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE,            RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING); }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);}int BufferElements2Rec = 1024; // want to play 2048 (2K) since 2 bytes we use only 1024int BytesPerElement = 2; // 2 bytes in 16bit formatprivate void startRecording() {    recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,            RECORDER_SAMPLERATE, RECORDER_CHANNELS,            RECORDER_AUDIO_ENCODING, BufferElements2Rec * BytesPerElement);    recorder.startRecording();    isRecording = true;    recordingThread = new Thread(new Runnable() {        public void run() {            writeAudioDataToFile();        }    }, "AudioRecorder Thread");    recordingThread.start();}    //convert short to byteprivate byte[] short2byte(short[] sData) {    int shortArrsize = sData.length;    byte[] bytes = new byte[shortArrsize * 2];    for (int i = 0; i < shortArrsize; i++) {        bytes[i * 2] = (byte) (sData[i] & 0x00FF);        bytes[(i * 2) + 1] = (byte) (sData[i] >> 8);        sData[i] = 0;    }    return bytes;}private void writeAudioDataToFile() {    // Write the output audio in byte    String filePath = "/sdcard/voice8K16bitmono.pcm";    short sData[] = new short[BufferElements2Rec];    FileOutputStream os = null;    try {        os = new FileOutputStream(filePath);    } catch (FileNotFoundException e) {        e.printStackTrace();    }    while (isRecording) {        // gets the voice output from microphone to byte format        recorder.read(sData, 0, BufferElements2Rec);        System.out.println("Short wirting to file" + sData.toString());        try {            // // writes the data to file from buffer            // // stores the voice buffer            byte bData[] = short2byte(sData);            os.write(bData, 0, BufferElements2Rec * BytesPerElement);        } catch (IOException e) {            e.printStackTrace();        }    }    try {        os.close();    } catch (IOException e) {        e.printStackTrace();    }}private void stopRecording() {    // stops the recording activity    if (null != recorder) {        isRecording = false;        recorder.stop();        recorder.release();        recorder = null;        recordingThread = null;    }}private View.OnClickListener btnClick = new View.OnClickListener() {    public void onClick(View v) {        switch (v.getId()) {        case R.id.btnStart: {            enableButtons(true);            startRecording();            break;        }        case R.id.btnStop: {            enableButtons(false);            stopRecording();            break;        }        }    }};@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {    if (keyCode == KeyEvent.KEYCODE_BACK) {        finish();    }    return super.onKeyDown(keyCode, event);}}