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からサービスクラスのメソッドを呼び出すには、私はActivityクラスのメソッドすなわちstartPlay（）からサービスクラスすなわちgetDur（）のメソッドを呼び出すようにしようとしていますが、私はNULLポインタ例外を取得しています。以下はプロジェクトのコードです。私もいくつかのログステートメントを追加しましたが、ログには何も印刷されません。nullポインタ例外アクティビティクラス
Herrewareサービスクラスをアクティビティクラスとバインドしようとしています。教えてください。
songPlay.java
Imports *
public class songPlay extends AppCompatActivity {
private static final int UPDATE_FREQUENCY = 500;
private static final int STEP_VALUE = 4000;
private TextView songName = null;
private TextView songDurationCurrent = null;
private TextView songDurationTotal = null;
private TextView songArtistFile = null;
private SeekBar seekbar = null;
private ImageButton playButton = null;
private ImageButton prevButton = null;
private ImageButton nextButton = null;
private Drawable clipArt = null;
private ImageView albumCover = null;
MusicService musicService;
boolean mBound = false;
private boolean isStarted = false;
private boolean isMoveingSeekBar = false;
String songId="", songTitle="", songArtist="", songPath="";
private final Handler handler = new Handler();
private final Runnable updatePositionRunnable = new Runnable() {
public void run() {
updatePosition();
}
};
@Override
protected void onStart() {
super.onStart();
Log.v("Check", "OnStart");
Intent intent = new Intent(this, MusicService.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_song_play);
Intent intent = getIntent();
if (intent != null && intent.hasExtra("SONG_ID")) {
songId = intent.getStringExtra("SONG_ID");
songTitle = intent.getStringExtra("SONG_TITLE");
songArtist = intent.getStringExtra("SONG_ARTIST");
songPath = intent.getStringExtra("SONG_PATH");
songTitle = songTitle.replaceAll("\\s*\\([^\\)]*\\)\\s*", "");
songTitle = songTitle.replaceAll("\\[.*?\\]", "");
songArtist = songArtist.replaceAll("\\s*\\([^\\)]*\\)\\s*", "");
songName = (TextView) findViewById(R.id.selectedfile);
songName.setText(songTitle);
songArtistFile = (TextView) findViewById(R.id.selectedfile_artistname);
songArtistFile.setText(songArtist);
songDurationCurrent = (TextView) findViewById(R.id.duration_current);
songDurationTotal = (TextView) findViewById(R.id.duration_total);
seekbar = (SeekBar) findViewById(R.id.seekbar);
playButton = (ImageButton) findViewById(R.id.play);
prevButton = (ImageButton) findViewById(R.id.prev);
nextButton = (ImageButton) findViewById(R.id.next);
albumCover = (ImageView) findViewById(R.id.cover);
String selection = MediaStore.Audio.Media._ID + " = "+songId+"";
Cursor cursor = getContentResolver().query(
MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, new String[] {
MediaStore.Audio.Media._ID, MediaStore.Audio.Media.ALBUM_ID},
selection, null, null);
if (cursor.moveToFirst()) {
long albumId = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));
Uri sArtworkUri = Uri.parse("content://media/external/audio/albumart");
Uri albumArtUri = ContentUris.withAppendedId(sArtworkUri, albumId);
try {
albumCover.setImageURI(albumArtUri);
}
catch (Exception e) {
Log.e("Check", "Not Found");
}
}
cursor.close();
seekbar.setOnSeekBarChangeListener(seekBarChanged);
playButton.setOnClickListener(onButtonClick);
nextButton.setOnClickListener(onButtonClick);
prevButton.setOnClickListener(onButtonClick);
start();
}
}
@Override
protected void onDestroy() {
super.onDestroy();
handler.removeCallbacks(updatePositionRunnable);
isStarted = false;
}
private void start() {
startService(new Intent(getApplicationContext(), MusicService.class).putExtra("songPath", songPath));
startPlay();
}
private void startPlay() {
isStarted = true;
seekbar.setProgress(0);
seekbar.setMax(musicService.getDur());
long millis = musicService.getDur();
long second = (millis/1000) % 60;
long minute = (millis/(1000 * 60)) % 60;
long hour = (millis/(1000 * 60 * 60)) % 24;
String temp="",a="",b="",c="";
if(hour==0)
a = "00";
else if(hour<=9 && hour>0)
a = "0" + String.valueOf(hour);
else
a = String.valueOf(hour);
if(minute==0)
b = "00";
else if(minute<=9 && minute>0)
b = "0" + String.valueOf(minute);
else
b = String.valueOf(minute);
if(second==0)
c = "00";
else if(second<=9 && second>0)
c = "0" + String.valueOf(second);
else
c = String.valueOf(second);
temp = a + ":" + b + ":" + c;
songDurationTotal.setText(temp);
playButton.setImageResource(android.R.drawable.ic_media_pause);
isStarted = true;
updatePosition();
}
private void stopPlay() {
//musicService.stopPlay();
Intent intent = new Intent("songAction");
intent.putExtra("action", "stopPlay");
sendBroadcast(intent);
playButton.setImageResource(android.R.drawable.ic_media_play);
handler.removeCallbacks(updatePositionRunnable);
seekbar.setProgress(0);
isStarted = false;
}
private void updatePosition() {
handler.removeCallbacks(updatePositionRunnable);
seekbar.setProgress(musicService.getCPos());
long millis = musicService.getCPos();
long second = (millis/1000) % 60;
long minute = (millis/(1000 * 60)) % 60;
long hour = (millis/(1000 * 60 * 60)) % 24;
String temp="",a="",b="",c="";
if(hour==0)
a = "00";
else if(hour<=9 && hour>0)
a = "0" + String.valueOf(hour);
else
a = String.valueOf(hour);
if(minute==0)
b = "00";
else if(minute<=9 && minute>0)
b = "0" + String.valueOf(minute);
else
b = String.valueOf(minute);
if(second==0)
c = "00";
else if(second<=9 && second>0)
c = "0" + String.valueOf(second);
else
c = String.valueOf(second);
temp = a + ":" + b + ":" + c;
songDurationCurrent.setText(temp);
handler.postDelayed(updatePositionRunnable, UPDATE_FREQUENCY);
}
private View.OnClickListener onButtonClick = new View.OnClickListener() {
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.play: {
if (musicService.isPlay()) {
handler.removeCallbacks(updatePositionRunnable);
//musicService.pausePlay();
Intent intent = new Intent("songAction");
intent.putExtra("action", "pausePlay");
sendBroadcast(intent);
playButton.setImageResource(android.R.drawable.ic_media_play);
} else {
if (isStarted) {
//musicService.startAgain();
Intent intent = new Intent("songAction");
intent.putExtra("action", "startAgain");
sendBroadcast(intent);
playButton.setImageResource(android.R.drawable.ic_media_pause);
updatePosition();
} else {
start();
}
}
break;
}
case R.id.next: {
int seekto = musicService.getCPos() + STEP_VALUE;
if (seekto > musicService.getDur())
seekto = musicService.getDur();
//musicService.pausePlay();
Intent intent = new Intent("songAction");
intent.putExtra("action", "seekTo");
intent.putExtra("value", String.valueOf(seekto));
sendBroadcast(intent);
//musicService.startAgain();
break;
}
case R.id.prev: {
int seekto = musicService.getCPos() - STEP_VALUE;
if (seekto < 0)
seekto = 0;
//musicService.pausePlay();
/*
Intent intent = new Intent("songAction");
intent.putExtra("action", "pausePlay");
sendBroadcast(intent);
player.seekTo(seekto);
intent.putExtra("action", "startAgain");
sendBroadcast(intent);
//musicService.startAgain();
*/
Intent intent = new Intent("songAction");
intent.putExtra("action", "seekTo");
intent.putExtra("value", String.valueOf(seekto));
sendBroadcast(intent);
break;
}
}
}
};
private SeekBar.OnSeekBarChangeListener seekBarChanged = new SeekBar.OnSeekBarChangeListener() {
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
isMoveingSeekBar = false;
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
isMoveingSeekBar = true;
}
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
if (isMoveingSeekBar) {
// player.seekTo(progress);
Intent intent = new Intent("songAction");
intent.putExtra("action", "seekTo");
intent.putExtra("value", String.valueOf(progress));
sendBroadcast(intent);
}
}
};
private ServiceConnection mConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName className, IBinder service) {
Log.v("Check", "Service Connected");
MusicService.LocalBinder binder = (MusicService.LocalBinder) service;
musicService = binder.getService();
mBound = true;
}
@Override
public void onServiceDisconnected(ComponentName arg0) {
mBound = false;
}
};
}
MusicService.java
Imports*
public class MusicService extends Service {
String songPath = "", action = "";
MediaPlayer player = null;
private final IBinder mBinder = new LocalBinder();
private BroadcastReceiver yourReceiver;
@Override
public IBinder onBind(Intent arg0) {
return mBinder;
}
public class LocalBinder extends Binder {
MusicService getService() {
return MusicService.this;
}
}
public void onCreate() {
super.onCreate();
player = new MediaPlayer();
}
@Override
public int onStartCommand(Intent intent, int flags, final int startId) {
Log.v("Check", "Service Started");
songPath = intent.getStringExtra("songPath");
final IntentFilter theFilter = new IntentFilter();
player.setOnCompletionListener(onCompletion);
player.setOnErrorListener(onError);
player.stop();
player.reset();
try {
player.setDataSource(songPath);
player.prepare();
player.start();
}
catch (Exception e) {
}
this.yourReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if(action.equals("songAction")){
String state = intent.getExtras().getString("action");
if(state.equals("stopPlay")) {
stopPlay();
}
else if(state.equals("pausePlaye")) {
pausePlay();
}
else if(state.equals("startAgain")) {
startAgain();
}
else if(state.equals("seekTo")) {
int value = Integer.parseInt(intent.getExtras().getString("value"));
player.seekTo(value);
}
}
}
};
this.registerReceiver(this.yourReceiver, theFilter);
return START_NOT_STICKY;
}
@Override
public void onDestroy() {
super.onDestroy();
player.stop();
player.reset();
player.release();
player = null;
}
void stopPlay() {
player.stop();
player.reset();
}
void pausePlay() {
player.pause();
}
void startAgain() {
player.start();
}
private MediaPlayer.OnCompletionListener onCompletion = new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) {
stopPlay();
}
};
private MediaPlayer.OnErrorListener onError = new MediaPlayer.OnErrorListener() {
@Override
public boolean onError(MediaPlayer mp, int what, int extra) {
return false;
}
};
int getCPos() {
return player.getCurrentPosition();
}
int getDur() {
return player.getDuration();
}
boolean isPlay() {
return player.isPlaying();
}
}
のAndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.coderahul.player"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="10"
android:targetSdkVersion="24" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application
android:name="com.android.tools.fd.runtime.BootstrapApplication"
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.coderahul.player.MainActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.example.coderahul.beats.songPlay" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:enabled="true" android:process=":remote" android:name=".MusicService"/>
</application>
</manifest>
