How to use AutoValue with Retrofit 2?

问题

I've got AutoValue (and the android-apt plugin) working in a project, and I'm aware of Ryan Harter's gson extension for AutoValue, but how do I hook Retrofit 2 up to use the extension and factory method on the abstract class?

String grantType = "password";
Call<SignIn> signInCall = retrofitApi.signIn(email, password, grantType);
signInCall.enqueue(callback);

eg here I would like to use AutoValue with the SignIn JSON model object to enforce immutability but how do I hook up Retrofit (or perhaps more specifically Gson) to the immutable, AutoValue model class?

回答1:

[update] The library have changed a bit, check more here: https://github.com/rharter/auto-value-gson

I was able to make it work like this. I hope it will help you.

Import in your gradle app file

apt 'com.ryanharter.auto.value:auto-value-gson:0.3.1'

Create object with autovalue:

@AutoValue public abstract class SignIn {    
    @SerializedName("signin_token") public abstract String signinToken();
    @SerializedName("user") public abstract Profile profile();

    public static TypeAdapter<SignIn> typeAdapter(Gson gson) {
        return new AutoValue_SignIn.GsonTypeAdapter(gson);
    }
}

Create your Type Adapter Factory (Skip if using version > 0.3.0)

public class AutoValueGsonTypeAdapterFactory implements TypeAdapterFactory {

    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
        Class<? super T> rawType = type.getRawType();

        if (rawType.equals(SignIn.class)) {
            return (TypeAdapter<T>) SignIn.typeAdapter(gson);
        } 

        return null;
    }
}

Create your Gson converter with your GsonBuilder

GsonConverterFactory gsonConverterFactory = GsonConverterFactory.create(
        new GsonBuilder()
                .registerTypeAdapterFactory(new AutoValueGsonTypeAdapterFactory())
                .create());

Add it to your retrofit builder

Retrofit retrofit = new Retrofit
        .Builder()
        .addConverterFactory(gsonConverterFactory)
        .baseUrl("http://url.com/")
        .build()

Do your request
Enjoy

Bonus live template:
In your autovalue class, type avtypeadapter then autocomplete to generate the type adapter code. To work you need to add this as a live template in Android Studio.

public static TypeAdapter<$class$> typeAdapter(Gson gson) {
    return new AutoValue_$class$.GsonTypeAdapter(gson);
}

How to create and use the live template.

回答2:

Here's a Gist by Jake Wharton for a Gson TypeAdapterFactory that just requires you add an annotation to all of your AutoValue classes that require working with Gson https://gist.github.com/JakeWharton/0d67d01badcee0ae7bc9

Works great for me.

Here's some proguard help too..

-keep class **.AutoValue_*
-keepnames @yourpackage.AutoGson class *

来源：https://stackoverflow.com/questions/36529238/how-to-use-autovalue-with-retrofit-2

标签

android

retrofit2

auto-value