Native support for java 8 Lambdas on Android

César Ferreira Blocked Unblock Follow Following Aug 22, 2016

A few months ago I wrote a tutorial about a simple way to incorporate java8 lambda features on Android (which only supports java 6/7 for now).

Well guess what? Android Nougat introduces support for Java 8 language features that you can use when developing apps that target Android version 24 from minSdkVersion 9 and up. We don’t need retrolambda no more :)

Here’s how to enable this feature on your build.gradle:

android {

...

defaultConfig {

...

minSdkVersion 9

...

targetSdkVersion 24

...

jackOptions.enabled true

}

compileOptions {

sourceCompatibility JavaVersion.VERSION_1_8

targetCompatibility JavaVersion.VERSION_1_8

}

}

You can now start writing shorter code…

Lambdas

So things like this:

button.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

log("Clicked");

}

});

Become this:

button.setOnClickListener(v -> log("Clicked"));

Method References

Sometimes a lambda expression does nothing but call an existing method. In those cases, it’s often clearer to refer to the existing method by name. Method references are compact, easy-to-read lambda expressions for methods that already have a name:

button.setOnClickListener((view) -> deactivate(view));

private void deactivate(View view) {

view.setActivated(false);

}

Can be called as a method reference:

button.setOnClickListener(this::deactivate);