我不明白为什么我的应用程序不断崩溃。谷歌分析一直说这次崩溃是我的应用程序中最常见的，我无法解决它。我已多次查看代码并且不知道如何解决问题。
这是错误：
java.lang.IllegalStateException: Could not execute method of the activity
at android.view.View$1.onClick(View.java:3969)
at android.view.View.performClick(View.java:4640)
at android.view.View$PerformClick.run(View.java:19421)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5579)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at android.view.View$1.onClick(View.java:3964)
... 11 more
Caused by: java.lang.NullPointerException
at com.soloinc.meip.RecordRap.onClick(RecordRap.java:371)
... 14 more
这是recordrap
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_record_rap);
//instrument name from previous activity
instrument_file_name = getIntent().getExtras().getString("instrument_file_name");
instrument_title = getIntent().getExtras().getString("instrument_title");
TextView tv = (TextView) findViewById(R.id.instrument_title);
tv.setText(instrument_title);
//getting buffer size for our audio specification
bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE,RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING);
//setting listeners for seek bars
seekBar1 = (SeekBar)(findViewById(R.id.seekBar1));
seekBar1.setOnSeekBarChangeListener(osbcl);
seekBar2 = (SeekBar)(findViewById(R.id.seekBar2));
seekBar2.setOnSeekBarChangeListener(osbcl);
// Get the AudioManager
AudioManager audioManager =
(AudioManager)this.getSystemService(Context.AUDIO_SERVICE);
// Set the volume of played media to maximum.
audioManager.setStreamVolume (
AudioManager.STREAM_MUSIC,
audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC),
0);
//saving beats data in List
if(savedInstanceState == null)
new SaveInputStreamTask(this).execute();
}
@Override
public void onStart() {
super.onStart();
// The rest of your onStart() code.
EasyTracker.getInstance(this).activityStart(this); // Add this method.
}
@Override
public void onStop() {
super.onStop();
// The rest of your onStop() code.
EasyTracker.getInstance(this).activityStop(this); // Add this method.
}
//Listener for seek bars
final SeekBar.OnSeekBarChangeListener osbcl = new SeekBar.OnSeekBarChangeListener() {
@Override
public void onStopTrackingTouch(SeekBar arg0) {
if(arg0.getId() == R.id.seekBar1)
{
seekBar1Value = arg0.getProgress();
Toast.makeText(getApplicationContext(), "Beat Volume:"+seekBar1Value, Toast.LENGTH_SHORT).show();
}
else
{
seekBar2Value = arg0.getProgress();
Toast.makeText(getApplicationContext(), "Lyrics Volume:"+seekBar2Value, Toast.LENGTH_SHORT).show();
}
simultaneousPlay();//whenever volume value changes play audios again to show change in volume level
}
@Override
public void onStartTrackingTouch(SeekBar arg0) {}
@Override
public void onProgressChanged(SeekBar arg0, int arg1, boolean arg2) {}
};
//initializing mediaplayer for playing beat
private void initializePlayer()
{
try
{
//int resID=getResources().getIdentifier(instrument_file_name.substring(0,instrument_file_name.length()-4), "raw", getPackageName());
player = MediaPlayer.create(this,Uri.parse(instrument_file_name));
player.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer arg0) {
isPlayingInstrument = false;
}
});
}
catch(Exception e)
{
System.out.print(e.getMessage());
}
}
//return file name with current millisecond
private String getFilename()
{
String filepath = Environment.getExternalStorageDirectory().getPath();
File file = new File(filepath,MEIP_FOLDER);
if(!file.exists()){
file.mkdirs();
}
String temp = file.getAbsolutePath() + "/" + mixed_file_name + MEIP_FILE_EXT_WAV;
recorded_rap_file_name = temp;
return temp;
}
//return temporary fileName
private String getTempFilename()
{
String filepath = Environment.getExternalStorageDirectory().getPath();
File file = new File(filepath,MEIP_FOLDER);
if(!file.exists()){
file.mkdirs();
}
return (file.getAbsolutePath() + "/" + MEIP_TEMP_FILE);
}
//This function records user voice
private void startRecording()
{
recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,RECORDER_SAMPLERATE, RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING, bufferSize);
recorder.startRecording();
isRecording = true;
recordingThread = new Thread(new Runnable() {
@Override
public void run()
{
saveLyricsPCMData(recorder);
//writePCMDataToFile(getTempFilename(),recorder);
}
},"AudioRecorder Thread");
recordingThread.start();
}
//this function saves recording PCM data to temp file
private void saveLyricsPCMData(AudioRecord ar)
{
short data[] = new short[bufferSize];
lyricsShortList.clear();
int read = 0;
while(isRecording)
{
read = ar.read(data, 0, bufferSize);
if(AudioRecord.ERROR_INVALID_OPERATION != read)
{
for(int k = 0; k < read; k++)
{
lyricsShortList.add(data[k]);
}
}
}
}
//this function executes when user stop recording
private void stopRecording()
{
if(null != recorder)
{
isRecording = false;
recorder.stop();
recorder.release();
recorder = null;
recordingThread = null;
}
//writePCMToWaveFile(getTempFilename(),getFilename());
//deleteTempFile();
}
//this function writes wav file header to out
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) (totalAudioLen & 0xff);
header[5] = (byte) ((totalAudioLen >> 8) & 0xff);
header[6] = (byte) ((totalAudioLen >> 16) & 0xff);
header[7] = (byte) ((totalAudioLen >> 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) ((RECORDER_BPP*channels) / 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) (totalDataLen & 0xff);
header[41] = (byte) ((totalDataLen >> 8) & 0xff);
header[42] = (byte) ((totalDataLen >> 16) & 0xff);
header[43] = (byte) ((totalDataLen >> 24) & 0xff);
out.write(header, 0, 44);
}
//onClick listeners for all the buttons
@Override
public void onClick(View view)
{
final Chronometer myChronometer = (Chronometer)findViewById(R.id.chronometer);
switch(view.getId())
{
case R.id.play_button:
if(isPlayingInstrument == false)
{
if(player == null){initializePlayer();}
isPlayingInstrument = true;
player.start();
myChronometer.setBase(SystemClock.elapsedRealtime());
}
break;
case R.id.pause_button:
line 366 player.pause();
isPlayingInstrument = false;
break;
case R.id.stop_button:
line 371 player.stop();
player = null;
isPlayingInstrument = false;
play_thread_running = false;
break;
case R.id.start_recording_button:
if(isRecording == false)
{
((ImageButton)findViewById(R.id.start_recording_button)).setImageResource(R.drawable.button_pause);
startRecording();
myChronometer.start();
}
break;
case R.id.stop_recording_button:
stopRecording();
myChronometer.stop();
play_thread_running = false;
((ImageButton)findViewById(R.id.start_recording_button)).setImageResource(R.drawable.button_record);
break;
case R.id.mix_and_play_button:
simultaneousPlay();
break;
case R.id.save_recording_button:
showDialog();
break;
case R.id.share_button:
share();
break;
}
}
public void share(){
if( mixed_file_name == null || mixed_file_name.equals(""))
{
Toast.makeText(this, "Save Your Song First!", Toast.LENGTH_SHORT).show();
return;
}
Bundle data = new Bundle();
data.putString("SHAREFILE", getFilename());
Message msg = mShareHandler.obtainMessage();
msg.setData(data);
mShareHandler.sendMessage(msg);
}
//play beat and lyrics simultaneously
public void simultaneousPlay()
{
if(play_thread_running == true){play_thread_running = false;}
try
{
beat_playing_thread = new Thread(new Runnable() {
@Override
public void run() {
play(buildShortArray(beatsShortList),seekBar1Value);
}
});
lyrics_playing_thread = new Thread(new Runnable() {
@Override
public void run() {
play(buildShortArray(lyricsShortList),seekBar2Value);
}
});
beat_playing_thread.start();
lyrics_playing_thread.start();
}
catch(Exception ex)
{
ex.printStackTrace();
}
}
//play an audio file
private void play(final short[] soundData, final int volume)
{
short[] output = new short[soundData.length];
// find the max:
float max = 0;
for (int i = 44; i < output.length; i++)
{
if (Math.abs((soundData[i])) > max)
{
max = Math.abs((soundData[i]));
}
}
// now find the result, with scaling:
float a,c;
for (int i = 44; i < output.length; i++)
{
a = (float)(soundData[i]);
c = Math.round(Short.MAX_VALUE * (a)/ max);
if (c > Short.MAX_VALUE)
c = Short.MAX_VALUE;
if (c < Short.MIN_VALUE)
c = Short.MIN_VALUE;
output[i] = (short) c;
}
AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, 22050, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize, AudioTrack.MODE_STREAM);
play_thread_running = true;
audioTrack.play();
audioTrack.setStereoVolume((float)(volume/100.0f), (float)(volume/100.0f));
int bufferSize = 512;
ShortBuffer sb = ShortBuffer.wrap(output);
short[] buffer = new short[bufferSize];
for(int i = 0 ; i < output.length-512 && play_thread_running == true; i = i+512)
{
sb.get(buffer, 0, 512);
audioTrack.write(buffer, 0, 512);
}
}
//this function mix audios
private byte[] mixSound() throws IOException
{
completeStreams(beatsShortList,lyricsShortList);
short[] output = new short[beatsShortList.size()];
// find the max:
float max = 0;
for (int i = 44; i < output.length; i++)
{
if (Math.abs((beatsShortList.get(i)*(seekBar1Value/100.0f)) + (lyricsShortList.get(i)*(seekBar2Value/100.0f))) > max)
{
max = Math.abs((beatsShortList.get(i)*(seekBar1Value/100.0f)) + (lyricsShortList.get(i)*(seekBar2Value/100.0f)));
}
}
// now find the result, with scaling:
float a, b, c;
for (int i = 44; i < output.length; i++) {
a = beatsShortList.get(i)*(seekBar1Value/100.0f);
b = lyricsShortList.get(i)*(seekBar2Value/100.0f);
c = Math.round(Short.MAX_VALUE * (a + b)/ max);
if (c > Short.MAX_VALUE)
c = Short.MAX_VALUE;
if (c < Short.MIN_VALUE)
c = Short.MIN_VALUE;
output[i] = (short) c;
}
ByteBuffer bb = ByteBuffer.allocate(output.length * 2);
bb.order(ByteOrder.LITTLE_ENDIAN);
bb.asShortBuffer().put(output);
byte[] bytes = bb.array();
return bytes;
}
//convert inputstream to byte array
public static byte[] getBytesFromInputStream(InputStream is)
{
ByteArrayOutputStream os = new ByteArrayOutputStream();
try
{
byte[] buffer = new byte[0xFFFF];
for (int len; (len = is.read(buffer)) != -1;)
os.write(buffer, 0, len);
os.flush();
return os.toByteArray();
}
catch (IOException e)
{
return null;
}
}
public void saveInputStream(InputStream is) throws IOException
{
int n = 0;
DataInputStream in1;
in1 = new DataInputStream(is);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try
{
while ((n = in1.read()) != -1)
{
bos.write(n);
}
}
catch (IOException e)
{
e.printStackTrace();
}
ByteBuffer bb = ByteBuffer.wrap(bos.toByteArray());
bb.order(ByteOrder.LITTLE_ENDIAN);
ShortBuffer sb = bb.asShortBuffer();
for (int i = 0; i < sb.capacity(); i++) {
beatsShortList.add(sb.get(i));
}
}
//add zeros to shorter audio
public void completeStreams(List<Short> l1,List<Short> l2)
{
if(l1.size() > l2.size())
{
while(l1.size() != l2.size())
{
l2.add((short)0);
}
}
if(l2.size() > l1.size())
{
while(l1.size() != l2.size())
{
l1.add((short)0);
}
}
}
//converts short list to short array
public short[] buildShortArray(List<Short> list)
{
short[] arr = new short[list.size()];
for(int i = 0; i < list.size(); i++)
{
arr[i] = list.get(i);
}
return arr;
}
//overriding back button functionality
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK)) {
Log.d(this.getClass().getName(), "back button pressed");
if(player != null)
player.stop();
play_thread_running = false;
//beat_playing_thread.stop();
//lyrics_playing_thread.stop();
return super.onKeyDown(keyCode, event);
}
return true;
}
public void showDialog()
{
AlertDialog.Builder alert = new AlertDialog.Builder(this);
alert.setTitle("What's Your Song Name!");
alert.setMessage("Song Name");
// Set an EditText view to get user input
final EditText input = new EditText(this);
alert.setView(input);
alert.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
mixed_file_name = input.getText().toString();
new SaveFileTask(RecordRap.this).execute();
//progress = ProgressDialog.show(getApplicationContext(), "", "Mixing and Saving...");
}
});
alert.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
// Canceled.
}
});
答案 0 :(得分：2)
这是一个小的重新分解，以解决至少部分NPE问题。我不知道这个功能是否正确，因为我没有看你的整个应用程序，但它应该指向正确的方向。对于播放逻辑，我假设有时您的initializePlayer()方法无法根据您的错误报告将播放器设置为非空值。
case R.id.play_button:
if(isPlayingInstrument == false) {
if(player == null)
initializePlayer();
if(player != null) {
isPlayingInstrument = true;
player.start();
myChronometer.setBase(SystemClock.elapsedRealtime());
}
}
break;
case R.id.pause_button:
if(player != null) {
player.pause();
isPlayingInstrument = false;
}
break;
case R.id.stop_button:
if(player != null) {
player.stop();
player = null;
isPlayingInstrument = false;
play_thread_running = false;
}
break;