App Bundle, split APKs and LinkageError
Troubleshoot or avoid crashes when using ObjectBox db and Android App Bundle or due to buggy devices. Google-certified devices prevent this crash.
Your app might observe crashes due to
UnsatisfiedLinkError
or (since ObjectBox 2.3.4) LinkageError
on some devices. This has mainly two reasons:- If your app uses the App Bundle format, the legacy split APK feature or Multidex the native library can't be found.
- Or if your app's minimum SDK level is below API 23 (Marshmallow), there are known bugs in Android's native library loading code.
When using an App Bundle or split APKs Google Play only delivers the split APKs required for each user's device configuration, including its architecture (ABI). If users bypass Google Play to install your app ("sideloading") they might not install all of the required split APKs. If the split APK containing the ObjectBox native library required for the device ABI is missing, your app will crash with
LinkageError
when building BoxStore.Update August 2020: Google-certified devices (those running Google Play Services) or those running Android 10 (API level 29) or higher prevent users from sideloading split APKs, preventing this crash. Adding the below check is no longer necessary for these devices.
implementation 'com.google.android.play:core:1.7.3'
In the
Application
class add the missing split APKs check before calling super.onCreate()
:public class App extends Application {
@Override
public void onCreate() {
if (MissingSplitsManagerFactory.create(this).disableAppIfMissingRequiredSplits()) {
return; // Skip app initialization.
}
super.onCreate();
// ...
}
}
If a broken installation is detected, users will see a message and Reinstall button asking them to re-install the app from Google Play.
If the Play Core library should not be used, there are two alternatives:
You can guard the MyObjectBox build call and for example display an activity with an info message (e.g. direct users to reinstall the app from Google Play, send you an error report, ...):
// guard the build call and set some flag (here setting the boxStore field null)
try {
boxStore = MyObjectBox.builder()
.androidContext(context.getApplicationContext())
.build();
} catch (LinkageError e) {
boxStore = null;
Log.e(App.TAG, "Failed to load ObjectBox: " + e.getMessage());
}
// then for example in the main activity check the flag in onCreate and
// direct to an info/error message without the app crashing:
if (ObjectBox.get() == null) {
startActivity(new Intent(this, ErrorActivity.class));
finish();
return;
}
The simplest solution is to always include native libraries for all supported ABIs. However, this will increase the download size of your app for all users.
android {
bundle {
abi {
// This property is set to true by default.
enableSplit = false
}
}
}
On some devices and if your minimum SDK is below API 23 (Android 6.0 Marshmallow), loading the native library may fail with
LinkageError
due to known bugs in Android's native library loading code. To counter this ObjectBox includes support for the ReLinker tool which will try to extract the native library manually if loading it normally fails.To enable this, just add ReLinker to your dependencies:
// https://github.com/KeepSafe/ReLinker/releases
implementation 'com.getkeepsafe.relinker:relinker:1.4.1'
ObjectBox is calling ReLinker via reflection. If you are using ProGuard or Multidex, make sure to add keep rules so that ReLinker code is not stripped from the final app or is not in the primary dex file.
For ProGuard add this line:
-keep class com.getkeepsafe.relinker.** { *; }
For Multidex add a multiDexKeepProguard file to your build file:
android {
buildTypes {
release {
multiDexKeepProguard file('multidex-config.pro')
}
}
}
And in the multidex-config.pro file add the same rule as above:
-keep class com.getkeepsafe.relinker.** { *; }
Multidex supports two file formats to keep files. We are using the ProGuard format (multiDexKeepProguard property). You can also use the multiDexKeepFile property, but make sure to adapt the rule above to that format.
To enable debug logs for ReLinker you can pass a custom
ReLinkerInstance
when building BoxStore
:boxStore = MyObjectBox.builder()
.androidContext(App.this)
.androidReLinker(ReLinker.log(new ReLinker.Logger() {
@Override
public void log(String message) { Log.d(TAG, message); }
}))
.build();
Last modified 2yr ago