Fatal Exception: java.lang.NullPointerException Attempt to invoke virtual method 'int java.lang.String.length()' on a null object reference

[KailuZhang]

Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.length()' on a null object reference
at java.net.URLEncoder.encode + 204(URLEncoder.java:204)
at pl.mobiltek.paymentsmobile.dotpay.utils.WebViewHelper$QueryString.encode + 161(WebViewHelper.java:161)
at pl.mobiltek.paymentsmobile.dotpay.utils.WebViewHelper$QueryString.add + 154(WebViewHelper.java:154)
at pl.mobiltek.paymentsmobile.dotpay.utils.WebViewHelper.getQueryString + 58(WebViewHelper.java:58)
at pl.mobiltek.paymentsmobile.dotpay.fragment.WebViewFragment.postRelaese + 133(WebViewFragment.java:133)
at pl.mobiltek.paymentsmobile.dotpay.fragment.WebViewFragment.postPaymentData + 128(WebViewFragment.java:128)
at pl.mobiltek.paymentsmobile.dotpay.fragment.WebViewFragment.onCreateView + 93(WebViewFragment.java:93)
at androidx.fragment.app.Fragment.performCreateView + 2595(Fragment.java:2595)
at androidx.fragment.app.FragmentManagerImpl.moveToState + 881(FragmentManagerImpl.java:881)
at androidx.fragment.app.FragmentManagerImpl.moveFragmentToExpectedState + 1238(FragmentManagerImpl.java:1238)
at androidx.fragment.app.FragmentManagerImpl.moveToState + 1303(FragmentManagerImpl.java:1303)
at androidx.fragment.app.FragmentManagerImpl.dispatchStateChange + 2656(FragmentManagerImpl.java:2656)
at androidx.fragment.app.FragmentManagerImpl.dispatchActivityCreated + 2610(FragmentManagerImpl.java:2610)
at androidx.fragment.app.FragmentController.dispatchActivityCreated + 246(FragmentController.java:246)
at androidx.fragment.app.FragmentActivity.onStart + 542(FragmentActivity.java:542)
at androidx.appcompat.app.AppCompatActivity.onStart + 201(AppCompatActivity.java:201)
at pl.mobiltek.paymentsmobile.dotpay.activity.PaymentActivity.onStart + 109(PaymentActivity.java:109)
at android.app.Instrumentation.callActivityOnStart + 1391(Instrumentation.java:1391)
at android.app.Activity.performStart + 7347(Activity.java:7347)
at android.app.ActivityThread.handleStartActivity + 3116(ActivityThread.java:3116)
at android.app.servertransaction.TransactionExecutor.performLifecycleSequence + 180(TransactionExecutor.java:180)
at android.app.servertransaction.TransactionExecutor.cycleToPath + 165(TransactionExecutor.java:165)
at android.app.servertransaction.TransactionExecutor.executeLifecycleState + 142(TransactionExecutor.java:142)
at android.app.servertransaction.TransactionExecutor.execute + 70(TransactionExecutor.java:70)
at android.app.ActivityThread$H.handleMessage + 1926(ActivityThread.java:1926)
at android.os.Handler.dispatchMessage + 106(Handler.java:106)
at android.os.Looper.loop + 214(Looper.java:214)
at android.app.ActivityThread.main + 6986(ActivityThread.java:6986)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run + 493(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main + 1445(ZygoteInit.java:1445)

[wpawel]

Please write more details on how the error was caused.