How do you import a library in the most recent and up-to-date versions of Android Studio (2017, 2.3.1+)?

Question

I'm wondering about this. I've been trying to import a library ("Time4J" Android version "Time4A") to a project in the Android Studio, and had to try a number of different things before getting it to "work". I finally managed to get it to import without errors, but now it crashes and doesn't want to work. Somehow I had managed to import it before and it worked without crashing, now I can't replicate that.

The problem seems to me that there's a lot of out-of-date information here about how to import libraries, and nothing for the most recent and up-to-date versions of the Android Studio system (so I was using like 2, 3, 4-year old stuff to try and make this work and this changes fast because there doesn't seem to be anything available from 2017.) and I suspect this is why it's not working. How do you correctly import a library in the newest 2017 versions (2.3.1 and up)?

Answer 1

The recommended way is to import libraries as Gradle dependencies. As described on the Time4A GitHub page:

dependencies {
    compile group: 'net.time4j', name: 'time4j-android', version: '3.33-2017b'
}

Add this to your build.gradle and it will download and import the library.

Answer 2

First you'd better upgrade your build.gradle (Project) and add google() to buildscript and allprojects repositories.

Then you can add whatever dependency you want with new method called Implementation, as compile is deprecated.

dependencies {
implementation group: 'net.time4j', name: 'time4j-android', version: '3.33-2017b'
}