EasyBundler is a library to simplify converting state objects into Bundles for Android applications. This repository is also a demonstration of simple annotation processing for Android libraries.


In order to use EasyBundler you will need to add a compile dependency for the API as well as an annotationProcessor dependency for the compiler:

dependencies {
    compile 'pub.devrel.easybundler:easybundler-api:0.1.1'
    annotationProcessor 'pub.devrel.easybundler:easybundler-compiler:0.1.1'

Basic Usage

First, define a simple state class in your application and annotate it with @BundlerClass:

public class MyState {

    public String message;

    private int[] favoriteNumbers;

    public MyState() {}

    public int[] getFavoriteNumbers() {
        return favoriteNumbers;

    public void setFavoriteNumbers(int[] favoriteNumbers) {
        this.favoriteNumbers = favoriteNumbers;

There are a few important requirements for a state object to work with EasyBundler:

At compile time, EasyBundler will generate code like this:

public final class MyStateBundler {
  public static Bundle toBundle(MyState object) {
    Bundle bundle = new Bundle();
    bundle.putString("KEY_pub.devrel.bundler.objects.MyState_message", object.message);
    bundle.putIntArray("KEY_pub.devrel.bundler.objects.MyState_favoriteNumbers", object.getFavoriteNumbers());
    return bundle;

  public static MyState fromBundle(Bundle bundle) {
    MyState object = new MyState();
    object.message = (String) bundle.getString("KEY_pub.devrel.bundler.objects.MyState_message");
    object.setFavoriteNumbers((int[]) bundle.getIntArray("KEY_pub.devrel.bundler.objects.MyState_favoriteNumbers"));
    return object;

You can use the Bundler class directly in your application, but it's even easier to use the helper methods provided by EasyBundler.

For example to serialize an object to Bundle, use the EasyBundler.toBundle(Object) method. And to turn that Bundle back into an object, use the EasyBundler.fromBundle(Bundle, Class) method. Both of these methods will fail if there is no generated Bundler class available.

If you are passing objects through Intents, you can use the EasyBundler.putExtra(Intent, Object) and EasyBundler.fromIntent(Intent, Class) methods to quickly add objects to and retrieve objects from an Intent.


Is EasyBundler efficient?

EasyBundler does most of the heavy lifting at compile time to generate the Bundler classes, so bundling and unbundling objects should be very fast due to the limited use of reflection at runtime.

If you want to maximize efficiency by eliminating all reflection, use the Bundler classes directly rather than the EasyBundler helper methods (which have to do a Class lookup at runtime to find the Bundler classes).

Can I customize how EasyBundler serializes and deserializes?

Not yet! But if you have a use case that is blocked by the lack of customization please open an Issue so we can discuss it.

Does EasyBundler support inheritance?

No, the current version of EasyBundler only looks at properties of the annotated class, not its parent class(es).


To install the library to your mavenLocal() repository, run:

./gradlew clean build :bundler-api:jarRelease publishToMavenLocal

To publish to Bintray, run:

./gradlew clean build test :bundler-api:jarRelease bintrayUpload