Android P API Compatibility

[rantianhua]

I installed my app on Android P, there was a dialog showing "Detected problems with API compatibility (visit g.co/dev/appcompat for more info)" every time i launched my app. I enabled the new StrictMode feature and I got the stack trace:

09-18 14:42:15.389 27929-27929/com.xxx.xxx D/StrictMode: StrictMode policy violation: android.os.strictmode.NonSdkApiUsedViolation: Lsun/misc/Unsafe;->theUnsafe:Lsun/misc/Unsafe;
        at android.os.StrictMode.lambda$static$1(StrictMode.java:428)
        at android.os.-$$Lambda$StrictMode$lu9ekkHJ2HMz0jd3F8K8MnhenxQ.accept(Unknown Source:2)
        at java.lang.Class.getDeclaredField(Native Method)
        at com.google.gson.internal.UnsafeAllocator.create(UnsafeAllocator.java:41)
        at com.google.gson.internal.ConstructorConstructor$14.<init>(ConstructorConstructor.java:221)
        at com.google.gson.internal.ConstructorConstructor.newUnsafeAllocator(ConstructorConstructor.java:220)
        at com.google.gson.internal.ConstructorConstructor.get(ConstructorConstructor.java:96)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:101)
        at com.google.gson.Gson.getAdapter(Gson.java:457)
        at com.google.gson.internal.bind.CollectionTypeAdapterFactory.create(CollectionTypeAdapterFactory.java:53)
        at com.google.gson.Gson.getAdapter(Gson.java:457)
        at retrofit2.converter.gson.GsonConverterFactory.responseBodyConverter(GsonConverterFactory.java:63)
        at retrofit2.Retrofit.nextResponseBodyConverter(Retrofit.java:330)
        at retrofit2.Retrofit.responseBodyConverter(Retrofit.java:313)
        at retrofit2.ServiceMethod$Builder.createResponseConverter(ServiceMethod.java:739)
        at retrofit2.ServiceMethod$Builder.build(ServiceMethod.java:172)
        at retrofit2.Retrofit.loadServiceMethod(Retrofit.java:170)
        at retrofit2.Retrofit$1.invoke(Retrofit.java:147)
        at java.lang.reflect.Proxy.invoke(Proxy.java:1006)

So there is any solution or workaround not to reflect system non-open api?

[hamilyon]

#1305

[ChristopheVersieux]

I can confirm this is in latest version 2.8.5

This warning also appears in Google Play Developer console under compatibility issues.

[davidoakley]

This is still in the latest version 2.8.6, and is still appearing as a warning on the Google Play Developer console.

[mwshubham]

+1

[ravinderparihar]

Add androidx multidex in build.gradle it's working for me
implementation 'androidx.multidex:multidex:2.0.1'

[Marcono1234]

Probably related to #445

[zipswich]

I have the following:

    implementation 'androidx.multidex:multidex:2.0.1'
    implementation 'com.google.code.gson:gson:2.8.6'

I get:

StrictMode policy violation: 
android.os.strictmode.NonSdkApiUsedViolation: Lsun/misc/Unsafe;->theUnsafe:Lsun/misc/Unsafe;
        at android.os.StrictMode.lambda$static$1(StrictMode.java:407)
        at android.os.-$$Lambda$StrictMode$lu9ekkHJ2HMz0jd3F8K8MnhenxQ.accept(Unknown Source:2)
        at java.lang.Class.getDeclaredField(Native Method)
        at com.google.gson.internal.UnsafeAllocator.create(UnsafeAllocator.java:41)
        at com.google.gson.internal.ConstructorConstructor$14.<init>(ConstructorConstructor.java:221)
        at com.google.gson.internal.ConstructorConstructor.newUnsafeAllocator(ConstructorConstructor.java:220)
        at com.google.gson.internal.ConstructorConstructor.get(ConstructorConstructor.java:96)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:101)
        at com.google.gson.Gson.getAdapter(Gson.java:458)
        at com.google.gson.internal.bind.MapTypeAdapterFactory.getKeyAdapter(MapTypeAdapterFactory.java:142)
        at com.google.gson.internal.bind.MapTypeAdapterFactory.create(MapTypeAdapterFactory.java:125)
        at com.google.gson.Gson.getAdapter(Gson.java:458)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:117)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:166)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102)
        at com.google.gson.Gson.getAdapter(Gson.java:458)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:117)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:166)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102)
        at com.google.gson.Gson.getAdapter(Gson.java:458)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:117)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:166)
        at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102)
        at com.google.gson.Gson.getAdapter(Gson.java:458)
        at com.google.gson.Gson.fromJson(Gson.java:931)
        at com.google.gson.Gson.fromJson(Gson.java:870)

[Marcono1234]

Do you intentionally rely on Gson creating instances of classes without default constructor¹?

• If yes: Then I am not sure if there is any solution to this because Gson relies on internal JDK / Android methods to create instances of such classes. Though any hints for solutions to this are welcome.
• If no: Could you please try the method GsonBuilder.disableJdkUnsafe()? And for any failing classes either:
  • Add a default constructor
  • If it is a non-static inner class make the class static

Footnotes

1. default constructor = constructor without parameters ↩