Question

我试图将JSON反序列化为一个用Gson扩展LinkedHashMap的类。我能够直接将这一点直接写入LinkedHashMap，但是当我尝试使用LinkedHashMap的子类时，我收到了错误

java.lang.IllegalStateException：预期为BEGIN_OBJECT但在第1行第3行路径为STRING。

我需要使用的类型（我不拥有此类，因此无法使用其他任何选项）：

public class ValueMap extends LinkedHashMap<CharSequence, Object> {}

我必须定义一个InstanceCreator来解决CharSequence的问题。我试图反序列化的JSON是一个基本的例子：

{"people":[{"name":"name1","surname":"name2","age":12,"dogs":["spot","fluffy","batman"],"cars":[{"name":"name1","model":1933},{"name":"name2","model":343}]},{"name":"name2","surname":"name2","age":44,"dogs":["spot","test","jack"]}]}

更新以包含序列化/反序列化代码：

GsonBuilder gsonBuilder = new GsonBuilder();
gsonBuilder.registerTypeAdapter(CharSequence.class, new CharSequenceInstanceCreator());

Gson gson = gsonBuilder.create();

String serialized = gson.toJson(value);

LinkedHashMap<CharSequence, Object> deserialized = gson.fromJson(serialized, ValueMap.class);

CharSequenceInstanceCreator的样子：

public static class CharSequenceInstanceCreator implements InstanceCreator<CharSequence> {

    @Override
    public CharSequence createInstance(Type arg0) {
        return new String();
    }

}

Answer 1

定义JsonDeserializer而不是InstanceCreator。

public static class CharSequenceDeserializer implements JsonDeserializer<CharSequence> {

    @Override
    public CharSequence deserialize(JsonElement element, Type type,
            JsonDeserializationContext context) throws JsonParseException {
        return element.getAsString();
    }

}

并注册。

//  gsonBuilder.registerTypeAdapter(CharSequence.class, new CharSequenceInstanceCreator());
gsonBuilder.registerTypeAdapter(CharSequence.class, new CharSequenceDeserializer());

使用Gson

1 个答案: