我的应用程序中有一个按钮，可以在我的应用程序中启动服务。该服务需要获得许可才能运行。我已向服务添加了权限请求，但是当我按下按钮启动服务时，我的应用程序崩溃了。这是服务
public class MQTTService extends Service {
private PowerManager.WakeLock wakeLock;
private MqttAndroidClient clientPhone;
public static String uri;
private FusedLocationProviderClient fusedLocationClient;
private LocationRequest locationRequest;
public void MQTTService() {
clientPhone = new MqttAndroidClient(this, serverUri, clientId);
clientPhone.setCallback(new MqttCallback() {
public void connectComplete(boolean b, String s) {
}
@Override
public void connectionLost(Throwable throwable) {
}
@Override
public void messageArrived(String topic, MqttMessage mqttMessage) throws Exception {
Log.w("Mqtt", mqttMessage.toString());
Log.e("message ", String.valueOf(mqttMessage));
Toast.makeText(MQTTService.this, "Crash Occurred", Toast.LENGTH_SHORT).show();
Intent dialogIntent = new Intent(MQTTService.this, alert.class);
dialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(dialogIntent);
}
@Override
public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {
}
});
}
@Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("Not yet implemented");
}
@Override
public void onCreate() {
super.onCreate();
callPermissions();
requestLocationUpdates();
}
@Override
public void onDestroy() {
super.onDestroy();
if (wakeLock.isHeld()) {
wakeLock.release();
}
if(clientPhone!=null) {
/*unregisterResources is needed,otherwise receive this error:
has leaked ServiceConnection org.eclipse.paho.android.service.MqttAndroidClient*/
try {
clientPhone.unregisterResources();
clientPhone.close();
clientPhone.disconnect();
} catch (Exception e) {
e.printStackTrace();
}
}
unregisterReceiver(m_ScreenOffReceiver);
m_ScreenOffReceiver = null;
}
public void requestLocationUpdates() {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) == PermissionChecker.PERMISSION_GRANTED && ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PermissionChecker.PERMISSION_GRANTED) {
fusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
locationRequest = new LocationRequest();
locationRequest.setInterval(2000);
locationRequest.setFastestInterval(4000);
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
fusedLocationClient.requestLocationUpdates(locationRequest, new LocationCallback() {
@Override
public void onLocationResult(LocationResult locationResult) {
super.onLocationResult(locationResult);
uri = "http://maps.google.com/maps?saddr=" + locationResult.getLastLocation().getLatitude() + "," + locationResult.getLastLocation().getLongitude();
}
}, getMainLooper());
}
}
public void callPermissions(){
String[] permissions = {Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION};
Permissions.check(this/*context*/, permissions, null/*rationale*/, null/*options*/, new PermissionHandler() {
@Override
public void onGranted() {
// do your task.
requestLocationUpdates();
}
@Override
public void onDenied(Context context, ArrayList<String> deniedPermissions) {
super.onDenied(context, deniedPermissions);
callPermissions();
}
});
}
}
这是我的堆栈跟踪
2020-05-04 20:32:29.440 17319-17357/com.example.carcrashdetection E/Perf: Fail to get file list com.example.carcrashdetection
2020-05-04 20:32:29.440 17319-17319/com.example.carcrashdetection E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.carcrashdetection, PID: 17319
java.lang.RuntimeException: Unable to create service com.example.carcrashdetection.MQTTService: android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
at android.app.ActivityThread.handleCreateService(ActivityThread.java:4082)
at android.app.ActivityThread.access$1800(ActivityThread.java:231)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1968)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7682)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:516)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)
Caused by: android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
at android.app.ContextImpl.startActivity(ContextImpl.java:964)
at android.app.ContextImpl.startActivity(ContextImpl.java:940)
at android.content.ContextWrapper.startActivity(ContextWrapper.java:383)
at com.nabinbhandari.android.permissions.Permissions.check(Permissions.java:121)
at com.example.carcrashdetection.MQTTService.callPermissions(MQTTService.java:282)
at com.example.carcrashdetection.MQTTService.onCreate(MQTTService.java:95)
at android.app.ActivityThread.handleCreateService(ActivityThread.java:4070)
at android.app.ActivityThread.access$1800(ActivityThread.java:231)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1968)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:214)
at android.app.ActivityThread.main(ActivityThread.java:7682)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:516)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)
2020-05-04 20:32:29.440 17319-17357/com.example.carcrashdetection E/Perf: getFolderSize() : Exception_1 = java.lang.NullPointerException: Attempt to get length of null array
2020-05-04 20:32:29.444 17319-17319/com.example.carcrashdetection I/Process: Sending signal. PID: 17319 SIG: 9
我在原始服务中有更多方法，但出于这个问题的目的，我删除了它们，因为我不认为它们是问题所在。自从我添加了位置方法和访问位置的权限以来，我的应用程序开始崩溃。我调用权限是错误的吗？
最佳答案
您的问题与权限无关。您的应用程序在这里崩溃了:
2020-05-04 20:32:29.440 17319-17357/com.example.carcrashdetection E/Perf: getFolderSize() : Exception_1 = java.lang.NullPointerException: 尝试获取空数组的长度
关于java - 服务启动时尝试调用位置权限但应用程序崩溃，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/61600182/