GSON Class Type Converter

readme.md

Usage

gsonBuilder.registerTypeAdapterFactory(new ClassTypeAdapterFactory());

ClassTypeAdapter.java

public class ClassTypeAdapter extends TypeAdapter<Class<?>> {
    @Override
    public void write(JsonWriter jsonWriter, Class<?> clazz) throws IOException {
        if(clazz == null){
            jsonWriter.nullValue();
            return;
        }
        jsonWriter.value(clazz.getName());
    }

    @Override
    public Class<?> read(JsonReader jsonReader) throws IOException {
        if (jsonReader.peek() == JsonToken.NULL) {
            jsonReader.nextNull();
            return null;
        }
        Class<?> clazz = null;
        try {
            clazz = Class.forName(jsonReader.nextString());
        } catch (ClassNotFoundException exception) {
            throw new IOException(exception);
        }
        return clazz;
    }
}

ClassTypeAdapterFactory.java

public class ClassTypeAdapterFactory implements TypeAdapterFactory {
    @Override
    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
        if(!Class.class.isAssignableFrom(typeToken.getRawType())) {
            return null;
        }
        return (TypeAdapter<T>) new ClassTypeAdapter();
    }
}