Occasional NullPointerException when calling Gson.fromJson when converting to a TypedToken of type CopyOnWriteArraySet

Gson version

2.8.9

Java / Android version

Multiple Android versions (23+)

Description

NullPointerException when calling Gson.fromJson when converting to a TypedToken of type CopyOnWriteArraySet. This crash is noticed on user devices but not reproducible locally while debugging.

Here is the code that is causing the null pointer.

        CopyOnWriteArraySet<String> result;
        Type type = new TypeToken<CopyOnWriteArraySet<String>>() {
        }.getType();
        Gson gson = new Gson();
        result = gson.fromJson(json, type);

Exception stack trace

[kalyandechiraju]

Apparently the issue has not resurfaced when we made the below two changes:

1. Add complete proguard rules as per documentation
2. Avoid casting json directly to CopyOnWriteArraySet. Instead casted in to an ArrayList and then pass it to constructor of CopyOnWriteArraySet.

[BoboBirdFly]

thanks! I’ll try it