The Android version of Web3j is maintained on a separate branch to the Java 8+ supported main Web3j project.
The simple reason being that Web3j was originally written in Java 8 to target Java devs. Android came along after the fact following a request from just some guy…
Unfortunately this means that each Web3j release needs to be backported to Android, which is a maintenance nightmare, and inevitably means that the Android releases are always behind the main JVM releases.
Really what we need to do is eliminate the need to backport, and have a single project branch that can be used to cut releases for both platforms without comprimising features for users - i.e. we don’t want to force Java users to use old syntax, nor restrict Androiid users to more recent versions of the platform only.
The most logical solution IMHO is to rewrite the library in Kotlin, (please let me know if you think otherwise) but I’d be interested to hear any other opinions people may have, as a rewrite would be a time consuming undertaking.