Checking if a user has already signed in with the google account with Kotlin results in null pointer exception

Question

I'm trying to check if the user is already signed in to google in kotlin.

fun isSignedIn(): Boolean {
        println(FirebaseAuth.getInstance().currentUser)
        println(GoogleSignIn.getLastSignedInAccount(this))
        return GoogleSignIn.getLastSignedInAccount(this) != null
    }

However I'm not sure why I'm getting the null pointer exception for the line GoogleSignIn.getLastSignedInAccount(this):

java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference

I've been looking at other stackoverflow threads and following what has been suggested, but I'm not sure what the problem is.

https://stackoverflow.com/questions/38190253/android-google-sign-in-check-if-user-is-signed-in#:~:text=To%20check%20if%20the%20user%20is%20signed-in%2C%20call%20isConnected,isConnected().

Am I overlooking something very simple? Thank you.

I created a new class called "Authentication" and defined the function in this class. ```this``` is the application context — Mark, Oct 12 '21 at 22:52
How can this be both a Context and your Authentication class? — Tenfour04, Oct 13 '21 at 04:12

score 0 · Answer 1 · answered Oct 12 '21 at 22:45

Not sure why I'm getting the null pointer exception but if anyone else encounters the same problem, it seems:

FirebaseAuth.getInstance().currentUser != null

works fine too.

FirebaseAuth.getInstance().currentUser!!.displayName

gets the user name, where as

FirebaseAuth.getInstance().currentUser!!.uid

gets the uid

Checking if a user has already signed in with the google account with Kotlin results in null pointer exception

1 Answers1