java.lang.NoSuchFieldException: UNAVAILABLE

[jd565]

Gson version

2.8.9

Java / Android version

Android compileSdk 31, target Java 1.8

Description

After upgrading from gson 2.8.8 to 2.8.9, we started seeing the following exception:

    java.lang.AssertionError: java.lang.NoSuchFieldException: UNAVAILABLE
        at com.google.gson.internal.bind.TypeAdapters$EnumTypeAdapter.<init>(TypeAdapters.java:12)
        at com.google.gson.internal.bind.TypeAdapters$30.create(TypeAdapters.java:5)
        at com.google.gson.Gson.getAdapter(Gson.java:9)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:4)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:15)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:4)
        at com.google.gson.Gson.getAdapter(Gson.java:9)

This happens when gson is creating the EnumTypeAdapter for the following class:

enum class CallingStatus {
    @SerializedName("unavailable")
    UNAVAILABLE,
    @SerializedName("disabled")
    DISABLED,
    @SerializedName("requested")
    REQUESTED,
    @SerializedName("pending")
    PENDING,
    @SerializedName("enabled")
    ENABLED
}

This enum is written in kotlin, and the class is not kept by proguard (The serialized name annotations should be telling gson how to parse this)

If I log out this info on a release build like follows:

CallingStatus::class.java.declaredFields.filter { it.isEnumConstant }.joinToString("\n") {
            "${it.name} - ${it.get(null)} - ${(it.get(null) as CallingStatus).name}"
        }

I get:
a - UNAVAILABLE - UNAVAILABLE
b - DISABLED - DISABLED
c - REQUESTED - REQUESTED
d - PENDING - PENDING
e - ENABLED - ENABLED

Expected behavior

Gson doesn't crash creating a type adapter

Actual behavior

Gson crashes creating a type adapter

Reproduction steps

1. Create an enum class in kotlin and do not cover it with proguard
2. Build the project and try and create the type adapter

Exception stack trace

    java.lang.AssertionError: java.lang.NoSuchFieldException: UNAVAILABLE
        at com.google.gson.internal.bind.TypeAdapters$EnumTypeAdapter.<init>(TypeAdapters.java:12)
        at com.google.gson.internal.bind.TypeAdapters$30.create(TypeAdapters.java:5)
        at com.google.gson.Gson.getAdapter(Gson.java:9)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:4)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:15)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:4)
        at com.google.gson.Gson.getAdapter(Gson.java:9)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:4)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:15)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:4)
        at com.google.gson.Gson.getAdapter(Gson.java:9)
        at com.google.gson.internal.bind.CollectionTypeAdapterFactory.create(CollectionTypeAdapterFactory.java:5)
        at com.google.gson.Gson.getAdapter(Gson.java:9)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:4)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:15)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:4)
        at com.google.gson.Gson.getAdapter(Gson.java:9)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:4)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:15)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:4)
        at com.google.gson.Gson.getAdapter(Gson.java:9)
        at retrofit2.converter.gson.GsonConverterFactory.responseBodyConverter(GsonConverterFactory.java:1)
        at retrofit2.Retrofit.nextResponseBodyConverter(Retrofit.java:6)
        at retrofit2.Retrofit.responseBodyConverter(Retrofit.java:1)
        at retrofit2.HttpServiceMethod.createResponseConverter(HttpServiceMethod.java:2)
        at retrofit2.HttpServiceMethod.parseAnnotations(HttpServiceMethod.java:16)
        at retrofit2.ServiceMethod.parseAnnotations(ServiceMethod.java:5)
        at retrofit2.Retrofit.loadServiceMethod(Retrofit.java:4)
        at retrofit2.Retrofit$1.invoke(Retrofit.java:6)
        at java.lang.reflect.Proxy.invoke(Proxy.java:1006)
        at $Proxy2.b(Unknown Source)

[Marcono1234]

Are you sure the stack trace really comes from a device running Gson 2.8.9? The stack trace looks a lot like Gson 2.8.7 or lower (before #1495 was integrated):

• A NoSuchFieldException is thrown (most likely here)
• The exception is wrapped in an AssertionError (here)

The whole point of #1495 was to fix the situation you are seeing, where enum constant names were obfuscated, but have a @SerializedName annotation and Gson should be able to handle them.

The line numbers in the provided stack trace also look a bit suspicious, maybe ProGuard is messing with the Gson library itself (though that would not directly explain this issue).

[jd565]

I will try again but the changes I made before were upgrading to 2.8.9 (from 2.8.8), and then we started seeing these crashes, and when I downgraded back to 2.8.8, it started working fine again.

[jd565]

Having had another look it looks like you are right:

• We made some changes which meant this class was no longer kept by proguard
• At a similar time we updated gson from 2.8.6 to 2.8.9
• When I saw these crashes I assumed it was from the gson upgrade (though I did build a release build myself and still saw the crash, though I will assume this is a caching issue)
• I then downgraded to 2.8.8 and all the issues went away.