Prevent reaching 65k methods in Android

Question

Every unconsidered usage of external library results in Gradle error about reaching 65k methods. So I'm wondering what is the best solution to prevent this, and I would like not consider using Proguard custom settings.

What comes to my mind (of course if we are using open source libraries) is just downloading code and putting it to our project manually. Then we can delete unused classes and methods. It looks like we are playing Proguard role and it's time consuming.

Question

• But what is the difference between using Gradle to fetch jars and putting code manually? Or is it any difference in performance?

I will be thankful for any best practices in creating project with many libraries.

Note: I would like to stop thinking for now about Proguard custom settings, because it often produces warnings, where omitting them looks a bit weird for me by e.g. -dontwarn. Also I'm a bit afraid of using MultiDex support, which I thougt is not recommended.

Answer 1

One thing you can do in gradle is to get very specific about what code modules you're including.

For example:

compile 'com.google.android.gms:play-services:8.4.0'

will include a lot more stuff than just...

compile 'com.google.android.gms:play-services-location:8.4.0'

Generally it's best to let gradle manage the external dependencies. The biggest reason is that you can rest assured that you're getting a snapshot of the code tied to a specific version. If you just manually import code, it's very easy to lose track of which version of the code you're working with. A big risk to modifying (or selectively including) code from a 3rd party is when the 3rd party updates their code, perhaps to fix a major bug caused by a new version of Android, and they included some changes that botch your manual tweaks. Now you have more a complex problem on your hands than if you had just included it as a gradle dependency.