Try-with-resources desugaring support in Android's build tools

During one of the code reviews with my colleague I've noticed he used try-with-resources Java 7's feature. To my then latest knowledge, try-with-resources required minSdkVersion 19 (while our app's minSdkVersion is 16) - which is based on the following statement (see under SDK Tools, Revision 22.6 (March 2014)):

Added support for Java 7 language features like multi-catch, try-with-resources, and the diamond operator. These features require version 19 or higher of the Build Tools. Try-with-resources requires minSdkVersion 19; the rest of the new language features require minSdkVersion 8 or higher.

My colleague told me that neither Lint nor compiler haven't warned about that, which was strange - since I vividly remember they both did in the past. Bug in Lint could explain that, but how did it compile? We decided to review our assumptions.

Verifying 64-bit libraries are being loaded

If you're bundling native libraries inside your Android application, then you've probably already know that starting August 1, 2019, your apps published on Google Play will need to support 64-bit architectures. In this post I'll show how we can explicitly choose the 64-bit ABIs to run, and verify that the 64-bit library was indeed loaded at runtime.

The support 64-bit architectures guide provides a command for selecting which ABI libraries to use during the APK installation process:

# A successful install:
$ adb install --abi armeabi-v7a APK_FILE.apk
Success

This command can be handy when your APK includes several ABI libraries, your CPU able to run multiple ABIs and you want to explicitly specify which ABI to use.