Did we ever consider enabling Java 8 support, or is there any particular reason why we wouldn't want to do this? Doing this would enable using try-with-resources on all API levels still supported by Firefox, which e.g. allows for a nicer way of locally whitelisting certain StrictMode violations.

(In reply to Jan Henning [:JanH] from comment #0) > Did we ever consider enabling Java 8 support, or is there any particular > reason why we wouldn't want to do this? It was my understanding that we couldn't without targeting an API level higher than we do -- 19 or 21, IIRC. In the past there were also issues with bytecode and tooling, but I think those are all solved. If we can, we should, 'cuz Java 1.7 is pretty ancient now.

(In reply to Nick Alexander :nalexander [he/him] from comment #1) > (In reply to Jan Henning [:JanH] from comment #0) > > Did we ever consider enabling Java 8 support, or is there any particular > > reason why we wouldn't want to do this? > > It was my understanding that we couldn't without targeting an API level > higher than we do -- 19 or 21, IIRC. According to https://developer.android.com/studio/write/java8-support, some features are only supported only on API24, or in one case even API26, but everything else now works on any Android version when using a new enough Android plugin to build (not sure if literally *any* version, but certainly any version we still care about, i.e. API16 and up).

Doing so allow to use try-with-resources on all API levels supported by us, not just starting from API19. Unfortunately this step also introduces some additional ambiguities in overload resolution, which means that one of GeckoResult's "then" overloads needs to be renamed. We also take the opportunity to update to the current version of the Android Gradle plugin.

Comment on attachment 9006084 [details] Bug 1485439 - Upgrade to Java 8. r?nalexander,jchen Nick Alexander :nalexander [he/him] has approved the revision.

Comment on attachment 9006084 [details] Bug 1485439 - Upgrade to Java 8. r?nalexander,jchen Jim Chen [:jchen] [:darchons] has approved the revision.

Pushed by mozilla@buttercookie.de: https://hg.mozilla.org/integration/mozilla-inbound/rev/e3e41bd5523e Pre: Upgrade Android Gradle plugin. r=nalexander https://hg.mozilla.org/integration/mozilla-inbound/rev/d81912697dac Upgrade to Java 8. r=nalexander,jchen

https://hg.mozilla.org/mozilla-central/rev/e3e41bd5523e https://hg.mozilla.org/mozilla-central/rev/d81912697dac

It seems one side effect of this change is it requires any other project that depends on GeckoView to upgrade their target compatibility to 1.8, otherwise the build can fail with rather cryptic errors. For example, I had to manually update my local build of Focus. This is not necessarily bad, but maybe we should send out a message to relevant mailing lists as an announcement.

(In reply to Jim Chen [:jchen] [:darchons] from comment #8) > It seems one side effect of this change is it requires any other project > that depends on GeckoView to upgrade their target compatibility to 1.8, > otherwise the build can fail with rather cryptic errors. For example, I had > to manually update my local build of Focus. This is not necessarily bad, but > maybe we should send out a message to relevant mailing lists as an > announcement. Done: https://mail.mozilla.org/pipermail/mobile-firefox-dev/2018-September/002411.html.