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ユーザがandroid.Manifest.permission.ACCESS_FINE_LOCATIONを有効にしているかどうかを確認しようとしています。アプリケーションを実行すると、NullPointerExceptionエラーが発生します。許可をチェックしようとするとNullPointerExceptionが発生する
パッケージdtt.romano.rsrpechhulp;ここで
import android.app.Activity;
import android.content.Context;
import android.content.IntentSender;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.util.Log;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
public class LocationProvider extends MainActivity implements
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,LocationListener {
public abstract interface LocationCallback {
public void handleNewLocation(Location location);
}
public static final String TAG = LocationProvider.class.getSimpleName();
private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000;
private LocationCallback mLocationCallback;
private Context mContext;
private GoogleApiClient mGoogleApiClient;
private LocationRequest mLocationRequest;
public LocationProvider(Context context, LocationCallback callback) {
mGoogleApiClient = new GoogleApiClient.Builder(context)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
mLocationCallback = callback;
// Create the LocationRequest object
mLocationRequest = LocationRequest.create()
.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
.setInterval(10 * 1000) // 10 seconds, in milliseconds
.setFastestInterval(1 * 1000); // 1 second, in milliseconds
mContext = context;
}
public void connect() {
mGoogleApiClient.connect();
}
public void disconnect() {
if (mGoogleApiClient.isConnected()) {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
mGoogleApiClient.disconnect();
}
}
public void locationUpdate(){
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{
android.Manifest.permission.ACCESS_FINE_LOCATION
}, 10);
}else{
Location location = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if (location == null) {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
else {
mLocationCallback.handleNewLocation(location);
}
}
}
@Override
public void onConnected(Bundle bundle) {
Log.i(TAG, "Location services connected.");
locationUpdate();
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode) {
case 10:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
locationUpdate();
}
return;
}
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
/*
* Google Play services can resolve some errors it detects.
* If the error has a resolution, try sending an Intent to
* start a Google Play services activity that can resolve
* error.
*/
if (connectionResult.hasResolution() && mContext instanceof Activity) {
try {
Activity activity = (Activity)mContext;
// Start an Activity that tries to resolve the error
connectionResult.startResolutionForResult(activity, CONNECTION_FAILURE_RESOLUTION_REQUEST);
/*
* Thrown if Google Play services canceled the original
* PendingIntent
*/
} catch (IntentSender.SendIntentException e) {
// Log the error
e.printStackTrace();
}
} else {
/*
* If no resolution is available, display a dialog to the
* user with the error.
*/
Log.i(TAG, "Location services connection failed with code " + connectionResult.getErrorCode());
}
}
@Override
public void onLocationChanged(Location location) {
mLocationCallback.handleNewLocation(location);
}
}
エラーログです：
java.lang.NullPointerException: Attempt to invoke virtual method 'int android.content.Context.checkPermission(java.lang.String, int, int)' on a null object reference
at android.content.ContextWrapper.checkPermission(ContextWrapper.java:637)
at android.support.v4.content.ContextCompat.checkSelfPermission(ContextCompat.java:387)
at dtt.romano.rsrpechhulp.LocationProvider.onConnected(LocationProvider.java:68)
at com.google.android.gms.common.internal.zzk.zzk(Unknown Source)
at com.google.android.gms.common.api.internal.zzj.zzi(Unknown Source)
at com.google.android.gms.common.api.internal.zzh.zzpx(Unknown Source)
at com.google.android.gms.common.api.internal.zzh.onConnected(Unknown Source)
at com.google.android.gms.common.api.internal.zzl.onConnected(Unknown Source)
at com.google.android.gms.common.api.internal.zzc.onConnected(Unknown Source)
at com.google.android.gms.common.internal.zzj$zzg.zzqL(Unknown Source)
at com.google.android.gms.common.internal.zzj$zza.zzc(Unknown Source)
at com.google.android.gms.common.internal.zzj$zza.zzw(Unknown Source)
at com.google.android.gms.common.internal.zzj$zzc.zzqN(Unknown Source)
at com.google.android.gms.common.internal.zzj$zzb.handleMessage(Unknown Source)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
おそらくあなたはここから参照を取ることができます：http://stackoverflow.com/questions/37160465/marsmallow-changing-permissions-at-run-time-crashes-app/37161036#37161036 – Riten
これは実際にはリンクされていませんそれを複製して、再オープンを投票する。これは、パラメータとして 'this'を提供するとき、この特定のアンドロイドAPIの一般的な問題です。私たちが知っているように、これは[nullでもかまいません]（https://stackoverflow.com/questions/3789528/can-this-ever -be-null-in-java）... – eis