AutoValue: Moshi Extension
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rharter Merge pull request #108 from mczernek/parametrized-nullsafe
Correct creating costructor with nullable parametrized arguments.
Latest commit f71e415 Jun 6, 2018

AutoValue: Moshi Extension

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An extension for Google's AutoValue that creates a simple Moshi JsonAdapterFactory for each AutoValue annotated object.


Simply include auto-value-moshi in your project and add a public static method with the following signature to classes you want to get Moshi JsonAdapters. You can also annotate your properties using @Json to define an alternate name for de/serialization.

@AutoValue public abstract class Foo {
  abstract String bar();
  @Json(name="Baz") abstract String baz();

  public static JsonAdapter<Foo> jsonAdapter(Moshi moshi) {
    return new AutoValue_Foo.MoshiJsonAdapter(moshi);

Now build your project and de/serialize your Foo.

Generics support

If the annotated class uses generics, the static method needs a little modification. Simply add a Type[] parameter and pass it to the generated MoshiJsonAdapter class.

@AutoValue public abstract class Foo<T> {
    abstract T data();
    public static JsonAdapter<Foo<T>> jsonAdapter(Moshi moshi, Type[] types) {
        return new AutoValue_Foo.MoshiJsonAdapter(moshi, types);


Optionally, auto-value-moshi can create a single JsonAdapter.Factory so that you don't have to add each generated JsonAdapter to your Moshi instance manually.

To generate a JsonAdapter.Factory for all of your auto-value-moshi classes, simply create an abstract class that implements JsonAdapter.Factory and annotate it with @MoshiAdapterFactory, and auto-value-moshi will create an implementation for you. You simply need to provide a static factory method, just like your AutoValue classes, and you can use the generated JsonAdapter.Factory to help Moshi de/serialize your types.

public abstract class MyAdapterFactory implements JsonAdapter.Factory {

  // Static factory method to access the package
  // private generated implementation
  public static JsonAdapter.Factory create() {
    return new AutoValueMoshi_MyAdapterFactory();

Then you simply need to register the Factory with Moshi.

Moshi moshi = new Moshi.Builder()


Add a Gradle dependency:

annotationProcessor ''

// if you use the @MoshiAdapterFactory annotation, you'll need to add the 'annotations' artifact 
// as a provided dependency:
provided ''


Copyright 2015 Ryan Harter.

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