The option we will be using is Retrolambda (https://github.com/orfjackal/retrolambda). We will enable it by using a plugin for Android (https://github.com/evant/gradle-retrolambda).

It can be done by simply adding the following at the very top of the application's app/build.gradle file:

plugins {
    id "me.tatarka.retrolambda" version "3.4.0"
}

apply plugin: 'com.android.application'

Also, let's not forget to tell the IDE that we will be using Java 8 by adding the following block:

android {
    ...
    compileOptions {
        targetCompatibility 1.8
        sourceCompatibility 1.8
    }
}

Finally, if proguard is being used, adding a line---dontwarn java.lang.invoke.*--to your proguard file might come in handy.