有人可以帮助我解决问题吗？
我想在我的应用程序中添加Weather。我正在使用OpenWeatherMap API。 问题是：
启动应用程序时，它会崩溃，因为纬度和经度设置为null，但是为什么呢？ 当我检查电话是否给我一些经纬度时，是的，它给了我。
问题是这个 （Common.current_location.getLatitude（））， String.valueOf（Common.current_location.getLongitude（））
public class ActivitytoActivity extends AppCompatActivity {
public ActivitytoActivity() {
compositeDisposable = new CompositeDisposable();
Retrofit retrofit = RetrofitClient.getInstance();
mService = retrofit.create(IOpenWeatherMap.class);
}
//___________Navigation_________________
ImageView imgView;
CardView cardView_music;
CardView cardView_vid;
CardView cardView_live;
CardView cardView_eat;
CardView cardView_drive;
CardView cardView_shop;
CardView cardView_pay;
CardView cardView_date;
//____________Weather ID________________
ImageView iconweather;
TextView tempweather;
ProgressBar loading_weather;
LinearLayout linlayweather;
LinearLayout linlayall;
CardView cardview_weather;
CompositeDisposable compositeDisposable;
IOpenWeatherMap mService;
//____________Weather API_________________
private FusedLocationProviderClient fusedLocationProviderClient;
private LocationCallback locationCallback;
private LocationRequest locationRequest;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_activityto);
//_________Initialize for Weather_______________
linlayweather = findViewById(R.id.linlayweather);
cardview_weather = findViewById(R.id.cardview_weather);
iconweather = (ImageView) findViewById(R.id.iconweather);
tempweather = (TextView) findViewById(R.id.tempweather);
loading_weather = (ProgressBar) findViewById(R.id.loading_weather);
linlayall = (LinearLayout) findViewById(R.id.linlayall);
getWeatherInformation();
//_________Request Permissions (Weather)____________
Dexter.withContext(this)
.withPermissions(Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_FINE_LOCATION)
.withListener(new MultiplePermissionsListener() {
@Override
public void onPermissionsChecked(MultiplePermissionsReport
report) {
if (report.areAllPermissionsGranted()) {
buildLocationRequest();
buildLocationCallBack();
if (ActivityCompat.checkSelfPermission(ActivitytoActivity.this,
Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.
PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(
ActivitytoActivity.this, Manifest.permission.
ACCESS_COARSE_LOCATION) != PackageManager.
PERMISSION_GRANTED) {
return;
}else {
}
fusedLocationProviderClient = LocationServices.
getFusedLocationProviderClient(ActivitytoActivity.this);
fusedLocationProviderClient.requestLocationUpdates(locationRequest,
locationCallback, Looper.myLooper());
}
}
@Override
public void onPermissionRationaleShouldBeShown(List<PermissionRequest> list,
PermissionToken permissionToken) {
Snackbar.make(linlayall, "Permission Denied", Snackbar.LENGTH_LONG)
.show();
}
}).check();
//__________Initialize the Navigation CardViews_____________
imgView = (ImageView) findViewById(R.id.backArrow_img_activitytoactivity);
cardView_music = (CardView) findViewById(R.id.cardview_spotify);
cardView_vid = (CardView) findViewById(R.id.cardview_youtube);
cardView_live = (CardView) findViewById(R.id.cardview_twitch);
cardView_eat = (CardView) findViewById(R.id.cardview_lieferando);
cardView_drive = (CardView) findViewById(R.id.cardview_uber);
cardView_shop = (CardView) findViewById(R.id.cardview_amazon);
cardView_pay = (CardView) findViewById(R.id.cardview_paypal);
cardView_date = (CardView) findViewById(R.id.cardview_tinder);
//__________Navigation for the CardViews______________
imgView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(ActivitytoActivity.this,
MainActivity.class);
startActivity(intent);
}
});
cardView_music.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent1 = new Intent(ActivitytoActivity.this, Music.class);
startActivity(intent1);
}
});
cardView_vid.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent2 = new Intent(ActivitytoActivity.this, Videos.class);
startActivity(intent2);
}
});
cardView_live.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent3 = new Intent(ActivitytoActivity.this, Live.class);
startActivity(intent3);
}
});
cardView_eat.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent4 = new Intent(ActivitytoActivity.this, Eat.class);
startActivity(intent4);
}
});
cardView_drive.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent5 = new Intent(ActivitytoActivity.this, Drive.class);
startActivity(intent5);
}
});
cardView_shop.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent6 = new Intent(ActivitytoActivity.this, Shop.class);
startActivity(intent6);
}
});
cardView_pay.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent7 = new Intent(ActivitytoActivity.this, Pay.class);
startActivity(intent7);
}
});
cardView_date.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent8 = new Intent(ActivitytoActivity.this, Date.class);
startActivity(intent8);
}
});
}
private void getWeatherInformation() {
compositeDisposable.add(mService.getWeatherByLatLng(String.valueOf(Common.current_location.getLatitude()),
String.valueOf(Common.current_location.getLongitude()),
Common.APP_ID,
"metric")
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<WeatherResult>() {
@Override
public void accept(WeatherResult weatherResult) throws Exception {
//Load Image
Picasso.get().load(new StringBuilder("https://openweathermap.org/img/wn/")
.append(weatherResult.getWeather().get(0).getIcon())
.append(".png").toString()).into(iconweather);
//Load Information
tempweather.setText(new StringBuilder(String.valueOf(weatherResult.getMain()
.getTemp())).append("°C").toString());
//Display panel
cardview_weather.setVisibility(View.VISIBLE);
loading_weather.setVisibility(View.GONE);
}
}, new Consumer<Throwable>() {
@Override
public void accept(Throwable throwable) throws Exception {
Toast.makeText(ActivitytoActivity.this, ""
+throwable.getMessage(), Toast.LENGTH_SHORT).show();
}
})
);
}
//___________Request Permissions Methods____________
private void buildLocationCallBack() {
locationCallback = new LocationCallback(){
@Override
public void onLocationResult(LocationResult locationResult){
super.onLocationResult(locationResult);
Common.current_location = locationResult.getLastLocation();
linlayall = (LinearLayout)findViewById(R.id.linlayall);
//Log
Log.d("Location", locationResult.getLastLocation().getLatitude()+"/"
+locationResult.getLastLocation().getLongitude());
}
};
}
private void buildLocationRequest() {
locationRequest = new LocationRequest();
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
locationRequest.setInterval(5000);
locationRequest.setFastestInterval(3000);
locationRequest.setSmallestDisplacement(10.0f);
}
}
那是我的错误
java.lang.RuntimeException: Unable to start activity ComponentInfo{company.rw.rexx/company.rw.rexx.ActivitytoActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'double android.location.Location.getLatitude()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2957)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3032)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1696)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6944)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'double android.location.Location.getLatitude()' on a null object reference
at company.rw.rexx.ActivitytoActivity.getWeatherInformation(ActivitytoActivity.java:224)
at company.rw.rexx.ActivitytoActivity.onCreate(ActivitytoActivity.java:98)
at android.app.Activity.performCreate(Activity.java:7183)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1220)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2910)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3032)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1696)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6944)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:327)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1374)