Getting Scala with Akka Actors Working on Android

I recently spent some time trying out Scala on Android, with good results. One of the things I wanted to get working on the Android platform was the Akka actor library, unfortunately this was not exactly a simple affair.

The ProGuard tool, which is a necessary part of the Scala-Android toolchain, needs configuration to make Akka work properly. While I found several ProGuard configurations for Akka online, I was not able to get any of them to work with the versions of Scala and Akka I was using. In the end, I had to manually debug the config with a cycle of building my project with Akka code included, then uploading my code to an android emulator. Once the code was running, I would wait for it to crash with a runtime exception, which would tell me what class was missing. I could then update my ProGuard config, rinse, and repeat.

Eventually I ended up with the following ProGuard configuration which allowed me to use use Akka 2.1.0 with Scala 2.10.1 on Android:

-keep class com.typesafe.**
-keep class akka.**
-keep class scala.collection.immutable.StringLike {
-keepclasseswithmembers class * {
    public (java.lang.String,$Settings, akka.event.EventStream,,;
-keepclasseswithmembers class * {
    public (;
-keep class scala.collection.SeqLike {
    public protected *;

I used this code to implement the “Suggest” examples from Ed Burnette’s “Hello Android” book using scala and Akka actors. The code for this project, including the full proguard config I used is on Github.

  • Adam Mackler says:

    Thanks for posting this. The ExtendedActorSystem constructor really had me stuck. I still don’t understand what’s going on with that, but at least it works the way you have it.

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