JSON SerializationDeserialization with AutoValue and Gson

Import in your gradle root file

classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'

Import in your gradle app file

apt 'com.google.auto.value:auto-value:1.2'  
apt 'com.ryanharter.auto.value:auto-value-gson:0.3.1'  
provided 'com.jakewharton.auto.value:auto-value-annotations:1.2-update1'  
provided 'org.glassfish:javax.annotation:10.0-b28'

Create object with autovalue:

@AutoValue public abstract class SignIn {    
    @SerializedName("signin_token") public abstract String signinToken();
    public abstract String username();

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

    public static SignIn create(String signin, String username) {
        return new AutoValue_SignIn(signin, username);
    }
}

Create your Gson converter with your GsonBuilder

Gson gson = new GsonBuilder()
                .registerTypeAdapterFactory(
                    new AutoValueGsonTypeAdapterFactory())
                .create());

Deserialize

String myJsonData = "{
  \"signin_token\": \"mySigninToken\",
  \"username\": \"myUsername\" }";
SignIn signInData = gson.fromJson(myJsonData, Signin.class);

Serialize

Signin myData = SignIn.create("myTokenData", "myUsername");
String myJsonData = gson.toJson(myData);

Using Gson is a great way to simplify Serialization and Deserialization code by using POJO objects. The side effect is that reflection is costly performance wise. That’s why using AutoValue-Gson to generate CustomTypeAdapter will avoid this reflection cost while staying very simple to update when an api change is happening.

Found a mistake? Have a question or improvement idea? Let me know.

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