Question

我正在尝试从JSON中的位置获取纬度和经度项，但我在Android上获得了一个超出范围的数组异常。

这是JSON文件：

{
"results" : [
  {
     "address_components" : [
        {
           "long_name" : "21211",
           "short_name" : "21211",
           "types" : [ "postal_code" ]
        },
        {
           "long_name" : "Baltimore",
           "short_name" : "Balt",
           "types" : [ "locality", "political" ]
        },
        {
           "long_name" : "Maryland",
           "short_name" : "MD",
           "types" : [ "administrative_area_level_1", "political" ]
        },
        {
           "long_name" : "United States",
           "short_name" : "US",
           "types" : [ "country", "political" ]
        }
     ],
     "formatted_address" : "Baltimore, MD 21211, USA",
     "geometry" : {
        "bounds" : {
           "northeast" : {
              "lat" : 39.3476939,
              "lng" : -76.619315
           },
           "southwest" : {
              "lat" : 39.310951,
              "lng" : -76.65690289999999
           }
        },
        "location" : {
           "lat" : 39.3289463,
           "lng" : -76.63838319999999
        },
        "location_type" : "APPROXIMATE",
        "viewport" : {
           "northeast" : {
              "lat" : 39.3476939,
              "lng" : -76.619315
           },
           "southwest" : {
              "lat" : 39.310951,
              "lng" : -76.65690289999999
           }
        }
     },
     "place_id" : "ChIJn-Z5WtQEyIkRQx9CtdQF7-I",
     "types" : [ "postal_code" ]
  }
],
"status" : "OK"
}

我只需要两个属性：

  "location" : {
           "lat" : 39.3289463,
           "lng" : -76.63838319999999
        }

我试过这样做但没有运气：

        JSONObject jObj = new JSONObject(jData);
        JSONArray results = jObj.getJSONArray("results");
        JSONObject geometry = results.getJSONObject(2); //ERROR RIGHT HERE!
        JSONObject  location = geometry.getJSONObject("location");
        Double latitude = location.getDouble("lat");
        Double longitude = location.getDouble("lng");

Answer 1

你应该得到JSONObject geometry = results.getJSONObject(0);，因为数组中只有一个对象。但是，如果我是你，我会创建一个ArrayList并使用for(int i = 0; i < results.size(); i++)来获取每个对象以防止出现多个对象，执行以下操作：

JSONObject jObj = new JSONObject(jData);
JSONArray results = jObj.getJSONArray("results");

ArrayList<LocationObject> _locationList = new ArrayList<>();

for(int i = 0; i < results.size(); i++){

    JSONObject geometry = results.getJSONObject(i).getJSONObject("geometry");

    JSONObject  location = geometry.getJSONObject("location");

    LocationObject _locationObject = new LocationObject();

    _locationObject.setLat(location.getDouble("lat"));
    _locationObject.setLng(location.getDouble("lng"));

    _locationObject.add(_locationObject);

}

Answer 2

你不能像你那样得到几何图形，因为json对象中的索引2没有对象。我认为你没有很好地格式化你的json响应。通过此web site复制您的回复，您就会理解。

以下是一些代码：

JSONObject tmp = results.getJSONObject(0);
JSONObject geometery = tmp.getJSONObject ("geometery");

Android：如何获取以下JSON对象？

2 个答案: