java - GSON 没有正确解析嵌套的 JSON 对象

Question

我有一些 JSON 格式的数据，并使用 GSON 库将其解析为 Java 对象，以便在代码的后续部分中使用。 JSON 有嵌套的对象，它们似乎没有被正确解析，我不明白为什么，因为外部对象正在按需要转换。这是我正在查看的 JSON 数据的示例:

{  
   "title":"Emergency Services Headquarters",
   "description":"",
   "cid":"C70856",
   "building_id":"4714",
   "building_number":"3542",
   "campus_code":"20",
   "campus_name":"Busch",
   "location":{  
      "name":"Emergency Services Headquarters",
      "street":"129 DAVIDSON ROAD",
      "additional":"",
      "city":"Piscataway",
      "state":"New Jersey",
      "state_abbr":"NJ",
      "postal_code":"08854-8064",
      "country":"United States",
      "country_abbr":"US",
      "latitude":"40.526306",
      "longitude":"-74.461470"
   },
   "offices":[  
      "Emergency Services"
   ]
}

我使用 codebeautify 创建了 JSON 所需的 Java 对象类(一切都在 Building.java 中):

public class Building {
    private String title;
    private String description;
    private String cid;
    private String building_id;
    private String building_number;
    private String campus_code;
    private String campus_name;
    Location LocationObject;
    ArrayList < Object > offices = new ArrayList < Object > ();

    //Setters and getters have been omitted

}

class Location {
    private String name;
    private String street;
    private String additional;
    private String city;
    private String state;
    private String state_abbr;
    private String postal_code;
    private String country;
    private String country_abbr;
    private String latitude;
    private String longitude;

    //Setters and getters have been omitted
}

这是我用来解析 JSON 的代码，其中变量 json 是该方法的输入参数:

Gson obj = new Gson();
JsonArray buildingsArray = new JsonArray();
JsonParser parser = new JsonParser();
JsonElement jsonElement = parser.parse(json);
buildingsArray = jsonElement.getAsJsonArray();
for (int i = 0; i < buildingsArray.size(); i++)
    Building building = obj.fromJson(buildingsArray.get(i), Building.class);

当我调用 building.getTitle() 或 building.getCid() 等方法时，我得到了适当的值，但是当我调用 building.getLocation()(其中 Location 是一个单独的对象)时，代码返回 null。我还没弄明白，这是 GSON 工作方式的问题吗？还是我的代码做错了什么？

Answer 1

首先，改变:

Location LocationObject;

到:

private Location location;

而且，您可以更轻松地反序列化 JSON:

Gson gson = new GsonBuilder().create();
Building building = gson.fromJson(json, Building.class);