Android 新意图中的NullPointerException
我正试图从Android 新意图中的NullPointerException,android,android-intent,nullpointerexception,android-service,android-notifications,Android,Android Intent,Nullpointerexception,Android Service,Android Notifications,我正试图从服务发送消息,但收到一个错误 com.spynetstation.MediaService.notif处出错(MediaService.java:162) 在服务中指向这一行的: Intent notificationIntent = new Intent(ctx, MediaService.class); 服务: public class MediaService extends Service implements OnPreparedListener,OnCompletionL
服务发送消息,但收到一个错误
com.spynetstation.MediaService.notif处出错(MediaService.java:162)
在服务中指向这一行的:
Intent notificationIntent = new Intent(ctx, MediaService.class);
服务:
public class MediaService extends Service implements OnPreparedListener,OnCompletionListener{
static MediaPlayer mediaPlayer;
static NotificationManager nm;
private static NotificationCompat.Builder mBuilder;
static Context ctx;
static String dataPlaying = null;
static String soursetrack = null;
static TimerTask repeatTask;
static Timer t;
Node node;
static String filePath;
static File file;
String titleNotif = "Station";
String contentNotif = "Running";
public IBinder onBind(Intent paramIntent) {
return null;
}
public static void initMP(String urlStream){
try {
mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource(urlStream);
} catch (IOException e) {
e.printStackTrace();
}
mediaPlayer.prepareAsync();
Log.d("MediaService", "prepareAsync");
}
public static void startMP(){
mediaPlayer.setOnPreparedListener(new OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
mp.start();
Log.d("MediaService", "start");
MainActivity.visible();
if (MainActivity.track) {} else {doRepeatTask();}
}
});
}
public static void stopMP() {
if (mediaPlayer != null) {
try {
mediaPlayer.stop();
Log.d("MediaService", "stop");
if (MainActivity.track) {} else {stopRepeatTask();}
} catch (Exception e) {
e.printStackTrace();
}
}
}
public static void releaseMP() {
if (mediaPlayer != null) {
try {
mediaPlayer.release();
Log.d("MediaService", "release");
mediaPlayer = null;
} catch (Exception e) {
e.printStackTrace();
}
}
}
@Override
public void onCompletion(MediaPlayer mp) {
Log.d("MediaService", "onCompletion");
}
@Override
public void onPrepared(MediaPlayer mp) {
Log.d("MediaService", "onPrepareed");
}
public void onCreate() {
super.onCreate();
// tried the following ctx=getBaseContext(); did not help
ctx = getApplicationContext();
this.nm = ((NotificationManager)getSystemService("notification"));
}
public void onDestroy() {
this.nm.cancelAll();
stopForeground(true);
}
public int onStartCommand(Intent paramIntent, int paramInt1, int paramInt2) {
try {
TimeUnit.SECONDS.sleep(0);
notif(titleNotif, contentNotif);
return super.onStartCommand(paramIntent, paramInt1, paramInt2);
} catch (InterruptedException localInterruptedException) {
for (;;) {
localInterruptedException.printStackTrace();
}
}
}
public static void notif(String titleNotif, String contentNotif){
//building the notification
mBuilder = new NotificationCompat.Builder(ctx)
.setSmallIcon(R.drawable.spy)
.setContentTitle(titleNotif)
.setTicker(contentNotif);
Intent notificationIntent = new Intent(ctx, MediaService.class);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
PendingIntent pendingIntent = PendingIntent.getActivity(ctx, 0,
notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);
mBuilder.setContentIntent(pendingIntent);
Notification n = mBuilder.build();
nm.notify(1, n);
// startForeground(12345, mBuilder.build());
}
public static void doRepeatTask(){
t = new Timer();
repeatTask = new TimerTask() {
public void run() {
new Task().execute();
}
};
t.schedule(repeatTask, 300, 3000);
}
public static void stopRepeatTask(){
if(repeatTask!=null){
repeatTask.cancel();
Log.d("TIMER", "timer canceled");
}
MainActivity.titleMusic.setText("");
MainActivity.titleMusic.setVisibility(View.GONE);
}
public static class Task extends AsyncTask<Void, Void, Void>{
@Override
protected Void doInBackground(Void... arg0) {
try {
URL url = new URL(soursetrack);
URLConnection connection = url.openConnection();
InputStream in = connection.getInputStream();
filePath = Environment.getExternalStorageDirectory().getAbsolutePath()
+ "/cashe.xml";
file = new File (filePath);
CreateFileFromInputStream(in, filePath) ;
// Parse it with document builder factory
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = null;
dBuilder = dbFactory.newDocumentBuilder();
Document doc = null;
doc = dBuilder.parse(file);
doc.getDocumentElement().normalize();
// The root element is
doc.getDocumentElement().getNodeName();
NodeList nList = doc.getElementsByTagName("Name");
for ( int i = 0 ; i < nList.getLength() ; i++ ) {
Element element = (Element) nList.item(i) ;
dataPlaying = getCharacterDataFromElement(element);
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
if (dataPlaying.equals(MainActivity.currentlyPlaying)){
if (MainActivity.replay == true){
MainActivity.replay = false;
MainActivity.titleMusic.setText("" + MainActivity.currentlyPlaying);
}
} else {
Log.d("MainActivity","Change track");
MainActivity.currentlyPlaying = dataPlaying;
MainActivity.titleMusic.setText("" + MainActivity.currentlyPlaying);
send();
}
super.onPostExecute(result);
}
}
public static void send(){
notif(MainActivity.currentlyPlaying,MainActivity.currentlyPlaying);
}
public static String getCharacterDataFromElement(Element e) {
Node node = e.getFirstChild();
if (node instanceof CharacterData) {
CharacterData cd = (CharacterData) node;
return cd.getData();
}
return "";
}
public static void CreateFileFromInputStream(InputStream inStream, String path)
throws IOException {
// write the inputStream to a FileOutputStream
OutputStream out = new FileOutputStream(new File(path));
int read = 0;
byte[] bytes = new byte[1024];
while ((read = inStream.read(bytes)) != -1) {
out.write(bytes, 0, read);
}
inStream.close();
out.flush();
out.close();
}
}
公共类MediaService扩展服务实现OnPreparedListener、OnCompletionListener{
静态媒体播放器;
静态通知管理器nm;
私有静态通知兼容性生成器mBuilder;
静态上下文ctx;
静态字符串数据播放=null;
静态字符串soursetrack=null;
静态时间任务;
静态定时器t;
节点;
静态字符串文件路径;
静态文件;
字符串titleNotif=“Station”;
字符串contentNotif=“Running”;
公共iBind onBind(意图参数意图){
返回null;
}
公共静态void initMP(字符串urlStream){
试一试{
mediaPlayer=新的mediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource(urlStream);
}捕获(IOE异常){
e、 printStackTrace();
}
mediaPlayer.prepareAsync();
Log.d(“MediaService”、“prepareAsync”);
}
公共静态void startMP(){
mediaPlayer.setOnPreparedListener(新的OnPreparedListener(){
@凌驾
已准备好公开作废(MediaPlayer mp){
mp.start();
Log.d(“MediaService”、“start”);
MainActivity.visible();
if(MainActivity.track){}else{doRepeatTask();}
}
});
}
公共静态void stopMP(){
如果(mediaPlayer!=null){
试一试{
mediaPlayer.stop();
Log.d(“MediaService”、“stop”);
if(MainActivity.track){}else{stopRepeatTask();}
}捕获(例外e){
e、 printStackTrace();
}
}
}
公共静态void releaseMP(){
如果(mediaPlayer!=null){
试一试{
mediaPlayer.release();
Log.d(“MediaService”、“发布”);
mediaPlayer=null;
}捕获(例外e){
e、 printStackTrace();
}
}
}
@凌驾
完成时的公共作废(MediaPlayer mp){
Log.d(“MediaService”、“onCompletion”);
}
@凌驾
已准备好公开作废(MediaPlayer mp){
Log.d(“MediaService”、“onPrepareed”);
}
public void onCreate(){
super.onCreate();
//尝试了以下ctx=getBaseContext();没有帮助
ctx=getApplicationContext();
this.nm=((NotificationManager)getSystemService(“通知”);
}
公共空间{
这个.nm.cancelAll();
停止前景(真);
}
公共int-onStartCommand(Intent-paramIntent、int-paramInt1、int-paramInt2){
试一试{
时间单位。秒。睡眠(0);
notif(titleNotif,contentNotif);
返回super.onStartCommand(paramIntent、paramInt1、paramInt2);
}捕获(中断异常局部中断异常){
对于(;;){
localInterruptedException.printStackTrace();
}
}
}
公共静态void notif(字符串titleNotif、字符串contentNotif){
//构建通知
mBuilder=新通知Compat.Builder(ctx)
.setSmallIcon(R.drawable.spy)
.setContentTitle(titleNotif)
.setTicker(contentNotif);
Intent notificationIntent=新意图(ctx,MediaService.class);
notificationIntent.setFlags(Intent.FLAG\u ACTIVITY\u SINGLE\u TOP);
PendingEvent PendingEvent=PendingEvent.getActivity(ctx,0,
notificationIntent,PendingEvent.FLAG_UPDATE_CURRENT);
mBuilder.setContentIntent(挂起内容);
通知n=mBuilder.build();
nm.notify(1,n);
//startForeground(12345,mBuilder.build());
}
公共静态void doRepeatTask(){
t=新定时器();
repeatTask=新时间任务(){
公开募捐{
新任务().execute();
}
};
t、 时间表(重复任务,3003000);
}
公共静态void stopRepeatTask(){
if(repeatTask!=null){
repeatTask.cancel();
Log.d(“计时器”,“计时器已取消”);
}
MainActivity.titleMusic.setText(“”);
MainActivity.titleMusic.setVisibility(View.GONE);
}
公共静态类任务扩展了异步任务{
@凌驾
受保护的Void doInBackground(Void…arg0){
试一试{
URL=新URL(soursetrack);
URLConnection=url.openConnection();
InputStream in=connection.getInputStream();
filePath=Environment.getExternalStorageDirectory().getAbsolutePath()
+“/cashe.xml”;
文件=新文件(文件路径);
CreateFileFromInputStream(在中,文件路径);
//使用文档生成器工厂解析它
DocumentBuilderFactory dbFactory=DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder=null;
dBuilder=dbFactory.newDocumentBuilder();
单据单据=空;
doc=dBuilder.parse(文件);
doc.getDocumentElement().normalize();
//根元素是
doc.getDocumentElement().getNodeName();
NodeList nList=doc.getElementsByTagName(“名称”);
对于(int i=0;i03-12 06:16:21.324: D/MediaService(3475): Change track
03-12 06:16:21.347: D/AndroidRuntime(3475): Shutting down VM
03-12 06:16:21.347: W/dalvikvm(3475): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
03-12 06:16:21.394: E/AndroidRuntime(3475): FATAL EXCEPTION: main
03-12 06:16:21.394: E/AndroidRuntime(3475): java.lang.NullPointerException
03-12 06:16:21.394: E/AndroidRuntime(3475): at android.content.ComponentName.<init>(ComponentName.java:75)
03-12 06:16:21.394: E/AndroidRuntime(3475): at android.content.Intent.<init>(Intent.java:3122)
03-12 06:16:21.394: E/AndroidRuntime(3475): at com.spynetstation.MediaService.notif(MediaService.java:162)
03-12 06:16:21.394: E/AndroidRuntime(3475): at com.spynetstation.MediaService.send(MediaService.java:250)
03-12 06:16:21.394: E/AndroidRuntime(3475): at com.spynetstation.MediaService$Task.onPostExecute(MediaService.java:241)
03-12 06:16:21.394: E/AndroidRuntime(3475): at com.spynetstation.MediaService$Task.onPostExecute(MediaService.java:1)
03-12 06:16:21.394: E/AndroidRuntime(3475): at android.os.AsyncTask.finish(AsyncTask.java:602)
03-12 06:16:21.394: E/AndroidRuntime(3475): at android.os.AsyncTask.access$600(AsyncTask.java:156)
03-12 06:16:21.394: E/AndroidRuntime(3475): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:615)
03-12 06:16:21.394: E/AndroidRuntime(3475): at android.os.Handler.dispatchMessage(Handler.java:99)
03-12 06:16:21.394: E/AndroidRuntime(3475): at android.os.Looper.loop(Looper.java:137)
03-12 06:16:21.394: E/AndroidRuntime(3475): at android.app.ActivityThread.main(ActivityThread.java:4424)
03-12 06:16:21.394: E/AndroidRuntime(3475): at java.lang.reflect.Method.invokeNative(Native Method)
03-12 06:16:21.394: E/AndroidRuntime(3475): at java.lang.reflect.Method.invoke(Method.java:511)
03-12 06:16:21.394: E/AndroidRuntime(3475): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
03-12 06:16:21.394: E/AndroidRuntime(3475): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
03-12 06:16:21.394: E/AndroidRuntime(3475): at dalvik.system.NativeStart.main(Native Method)
ctx= getApplicationContext();
Intent notificationIntent = new Intent(getApplicationContext(), MainActivity.class);
Intent notificationIntent = new Intent(ctx, MainActivity.class);
Intent notificationIntent = new Intent(getBaseContext(), MainActivity.class);
Intent notificationIntent = new Intent(getApplicationContext(), MainActivity.class);
Intent notificationIntent = new Intent(getApplicationContext(), MainActivity.class);
public class LauncherActivityname extends ..... {
public static Context context;
.
.
.
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context=this
}
}
Intent notificationIntent = new Intent(LauncherActivityname.context, MainActivity.class);