根据我的研究以及使用gson-2.0时，你确实不想使用registerTypeHierarchyAdapter方法，而是更平凡的registerTypeAdapter。而且，你当然不需要为派生类做instanceofs或编写适配器：只为基类或接口提供一个适配器，当然，你对派生类的默认序列化感到满意。无论如何，这是代码（删除了打包和导入）（也可以在github中找到）：

基类（在我的情况下为接口）：

public interface IAnimal { public String sound(); }

这两个派生类Cat：

public class Cat implements IAnimal {

    public String name;

    public Cat(String name) {
        super();
        this.name = name;
    }

    @Override
    public String sound() {
        return name + " : \"meaow\"";
    };
}

And Dog:

public class Dog implements IAnimal {

    public String name;
    public int ferocity;

    public Dog(String name, int ferocity) {
        super();
        this.name = name;
        this.ferocity = ferocity;
    }

    @Override
    public String sound() {
        return name + " : \"bark\" (ferocity level:" + ferocity + ")";
    }
}

IAnimalAdapter：

public class IAnimalAdapter implements JsonSerializer<IAnimal>, JsonDeserializer<IAnimal>{

    private static final String CLASSNAME = "CLASSNAME";
    private static final String INSTANCE  = "INSTANCE";

    @Override
    public JsonElement serialize(IAnimal src, Type typeOfSrc,
            JsonSerializationContext context) {

        JsonObject retValue = new JsonObject();
        String className = src.getClass().getName();
        retValue.addProperty(CLASSNAME, className);
        JsonElement elem = context.serialize(src); 
        retValue.add(INSTANCE, elem);
        return retValue;
    }

    @Override
    public IAnimal deserialize(JsonElement json, Type typeOfT,
            JsonDeserializationContext context) throws JsonParseException  {
        JsonObject jsonObject = json.getAsJsonObject();
        JsonPrimitive prim = (JsonPrimitive) jsonObject.get(CLASSNAME);
        String className = prim.getAsString();

        Class<?> klass = null;
        try {
            klass = Class.forName(className);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
            throw new JsonParseException(e.getMessage());
        }
        return context.deserialize(jsonObject.get(INSTANCE), klass);
    }
}

和测试类：

public class Test {

    public static void main(String[] args) {
        IAnimal animals[] = new IAnimal[]{new Cat("Kitty"), new Dog("Brutus", 5)};
        Gson gsonExt = null;
        {
            GsonBuilder builder = new GsonBuilder();
            builder.registerTypeAdapter(IAnimal.class, new IAnimalAdapter());
            gsonExt = builder.create();
        }
        for (IAnimal animal : animals) {
            String animalJson = gsonExt.toJson(animal, IAnimal.class);
            System.out.println("serialized with the custom serializer:" + animalJson);
            IAnimal animal2 = gsonExt.fromJson(animalJson, IAnimal.class);
            System.out.println(animal2.sound());
        }
    }
}

当运行Test :: main时，将得到以下输出：

serialized with the custom serializer:
{"CLASSNAME":"com.synelixis.caches.viz.json.playground.plainAdapter.Cat","INSTANCE":{"name":"Kitty"}}
Kitty : "meaow"
serialized with the custom serializer:
{"CLASSNAME":"com.synelixis.caches.viz.json.playground.plainAdapter.Dog","INSTANCE":{"name":"Brutus","ferocity":5}}
Brutus : "bark" (ferocity level:5)

我实际上也使用registerTypeHierarchyAdapter方法完成了上述操作，但这似乎需要实现自定义的DogAdapter和CatAdapter序列化器/反序列化器类，这在你想向Dog或Cat添加另一个字段时很难维护。