java.lang.NullPointerException inside initLayoutForFingerprint

[Vojtas87]

Hello,

I received this crash report in my app (Android 8.0, Xperia XA1 (G3121)):

`java.lang.NullPointerException
com.github.omadahealth.lollipin.lib.managers.AppLockActivity.initLayoutForFingerprint

java.lang.RuntimeException: Unable to resume activity {CustomPinActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.hardware.fingerprint.FingerprintManager.isHardwareDetected()' on a null object reference
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3754)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3794)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2980)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1663)
at android.os.Handler.dispatchMessage(Handler.java:108)
at android.os.Looper.loop(Looper.java:206)
at android.app.ActivityThread.main(ActivityThread.java:6749)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:845)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.hardware.fingerprint.FingerprintManager.isHardwareDetected()' on a null object reference
at com.github.omadahealth.lollipin.lib.managers.AppLockActivity.initLayoutForFingerprint(AppLockActivity.java:147)
at com.github.omadahealth.lollipin.lib.managers.AppLockActivity.onResume(AppLockActivity.java:84)
at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1355)
at android.app.Activity.performResume(Activity.java:7089)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3724)
... 10 more`

Could you take a look at this, please?

Thank you in advance.

[norrisboat]

@Vojtas87 make sure your activity extends PinActivity not your custom pin activity

[Vojtas87]

@norrisboat Yes, it does. My main activity (only this activity) extends PinCompatActivity.

[smsrobot]

I have same problem with my app, on Sony devices with android 8.0+ I am always getting this error in my error log, my activity extends "AppLockActivity".
It looks like "mFingerprintManager" is null in function initLayoutForFingerprint.

Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.hardware.fingerprint.FingerprintManager.isHardwareDetected()' on a null object reference
at com.github.omadahealth.lollipin.lib.managers.AppLockActivity.initLayoutForFingerprint(AppLockActivity.java:147)
at com.github.omadahealth.lollipin.lib.managers.AppLockActivity.onResume(AppLockActivity.java:84)
at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1355)
at android.app.Activity.performResume(Activity.java:7089)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:3724)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:3794)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2980)
at android.app.ActivityThread.-wrap11(Unknown Source)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1663)
at android.os.Handler.dispatchMessage(Handler.java:108)
at android.os.Looper.loop(Looper.java:206)
at android.app.ActivityThread.main(ActivityThread.java:6749)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:845)

[smsrobot]

This is forced solution for those who are using "AppLockActivity" as base class.
Extend your lock activity from this class, it has additional exception handling for null pointer exception, it will prevent you app from crashing - affected users will have fingerprint UI hidden.

public abstract class MyAppLockActivity extends AppLockActivity {

@Override
protected void onResume() {
    super.onResume();
    //Init layout for Fingerprint
    myInitLayoutForFingerprint();
}

/**
 * Init {@link FingerprintManager} of the {@link android.os.Build.VERSION#SDK_INT} is > to Marshmallow
 * and {@link FingerprintManager#isHardwareDetected()}.
 */
private void myInitLayoutForFingerprint() {
    mFingerprintImageView = (ImageView) this.findViewById(R.id.pin_code_fingerprint_imageview);
    mFingerprintTextView = (TextView) this.findViewById(R.id.pin_code_fingerprint_textview);
    if (mType == AppLock.UNLOCK_PIN && Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        mFingerprintManager = (FingerprintManager) getSystemService(Context.FINGERPRINT_SERVICE);
        mFingerprintUiHelper = new FingerprintUiHelper.FingerprintUiHelperBuilder(mFingerprintManager).build(mFingerprintImageView, mFingerprintTextView, this);
        try {
            if (mFingerprintManager.isHardwareDetected() && mFingerprintUiHelper.isFingerprintAuthAvailable()
                    && mLockManager.getAppLock().isFingerprintAuthEnabled()) {
                mFingerprintImageView.setVisibility(View.VISIBLE);
                mFingerprintTextView.setVisibility(View.VISIBLE);
                mFingerprintUiHelper.startListening();
            } else {
                mFingerprintImageView.setVisibility(View.GONE);
                mFingerprintTextView.setVisibility(View.GONE);
            }
        } catch (SecurityException e) {
            Log.e(TAG, e.toString());
            mFingerprintImageView.setVisibility(View.GONE);
            mFingerprintTextView.setVisibility(View.GONE);
        } catch (Exception e) {
            Log.e(TAG, e.toString());
            mFingerprintImageView.setVisibility(View.GONE);
            mFingerprintTextView.setVisibility(View.GONE);
        }
    } else {
        mFingerprintImageView.setVisibility(View.GONE);
        mFingerprintTextView.setVisibility(View.GONE);
    }
}

}

[Vojtas87]

@smsrobot Thanks. I will try your solution and I hope it will help my users. :-) Also I'm handling with another crash. Do you have some advice too, please? #184

[miralas]

@smsrobot I have same issue. My custom activity already extends AppLockActivity and uses your code example, but nothing! Android 8.0+ still crashing. :(

[anton-piliugin]

@smsrobot I have same issue. My custom activity already extends AppLockActivity and uses your code example, but nothing! Android 8.0+ still crashing. :(

Added some tips on how to fix:
#184 (comment)

[miralas]

@anton-piliugin yeah, thx, your solution works perfectly!