java.lang.ClassCastException：com.google.gson.internal.LinkedTreeMap无法强制转换为模型

After looking at * questions I could not find any solution that fix this problem.

在查看*问题后,我找不到解决此问题的任何解决方案。

I am trying to use GSON and have implemented a generic method like this:

我正在尝试使用GSON并实现了这样的通用方法:

public <T> List<T> deserializeList(String json) {
    Gson gson = new Gson();
    Type type = (new TypeToken<List<T>>() {}).getType();
    return  gson.fromJson(json, type);
}

Call to this method is done through this :

通过以下方式调用此方法:

parser.<Quote>deserializeList(result)

However the result that I am getting is this:

但是我得到的结果是这样的:

And when I am trying to access an object, I get this error:

当我试图访问一个对象时,我收到此错误:

 java.lang.ClassCastException: com.google.gson.internal.LinkedTreeMap cannot be cast to model.Quote

The JSON string is:

JSON字符串是:

[
    {
      "id": 269861,
      "quote": "People living deeply have no fear of death.",
      "author": "Anais Nin",
      "genre": "life",
      "tag": null,
      "createdAt": "2016-04-16T13:13:36.928Z",
      "updatedAt": "2016-04-16T13:13:36.928Z"
    }
]

2 个解决方案

#1

I would think you could write the method like so to explicitly provide the Type

我认为你可以像这样编写方法来显式提供Type

public <T> List<T> deserializeList(String json, Type type) {
    Gson gson = new Gson();
    return  gson.fromJson(json, type);
}

Though, passing around (new TypeToken<List<Model>>() {}).getType(); looks a little messy.

但是,传递(new TypeToken >(){})。getType();看起来有点乱。

I'm not too familiar with type erasure, but I bet that's related to the problem.

我不太熟悉类型擦除,但我敢打赌这与问题有关。

#2

The above parsing method is wrong and the following code is modified:

上面的解析方法是错误的,并修改了以下代码:

public static <T> List<T> getObjectList(String jsonString,Class<T> cls){
    List<T> list = new ArrayList<T>();
    try {
        Gson gson = new Gson();
        JsonArray arry = new JsonParser().parse(jsonString).getAsJsonArray();
        for (JsonElement jsonElement : arry) {
            list.add(gson.fromJson(jsonElement, cls));
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return list;
}

#1