Android 6.0以上の危険権限の取得

開始ページactivityでの権限要求の処理
 

import android.Manifest;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

public class LauncherActivity extends Activity {

    private static final int PERMISSIONS_REQUEST_CODE = 10;
    private static final String[] PERMISSIONS_REQUIRED = {Manifest.permission.WRITE_EXTERNAL_STORAGE};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (allPermissionsGranted()) {
            doAfterPermissionsGranted();
        } else {
            ActivityCompat.requestPermissions(this, PERMISSIONS_REQUIRED, PERMISSIONS_REQUEST_CODE);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == PERMISSIONS_REQUEST_CODE) {
            if (allPermissionsGranted()) {
                doAfterPermissionsGranted();
            } else {
                Toast.makeText(this, "Permissions not granted by the user.", Toast.LENGTH_SHORT).show();
                finish();
            }
        }
    }

    private void doAfterPermissionsGranted() {
        //      
    }

    private boolean allPermissionsGranted(){
        for(String permission: PERMISSIONS_REQUIRED){
            if(ContextCompat.checkSelfPermission(getBaseContext(), permission) != PackageManager.PERMISSION_GRANTED){
                return false;
            }
        }
        return true;
    }
}