JSON解析响应可以具有一个或多个对象

Question

我需要使用Android的JSON解析器，但我不能找到答案的任何地方的东西来解析在Android的这种反应是：

如何解析数据，如果例如“行程”可以包含一个或有时多个对象类型的行程？ 如果它包含一个比它返回这样的，但如果它包含更多的则是返回与[] 该示例“行程”不能放入JsonArray becouse显然不是数组。 （未放置在[右]）

我如何解析呢？任何例子？

  {
   "plan":{
      "date":"2010-10-20T00:00:00+02:00",
      "from":{
         "name":"Булевар Партизански Одреди",
         "stopId":"123",
         "lon":"21.373255285035548",
         "lat":"42.00736515785779",
         "geometry":"{\"type\": \"Point\", \"coordinates\": [21.373255285035548,42.00736515785779]}"
      },
      "to":{
         "name":"Булевар Партизански Одреди",
         "stopId":"123",
         "lon":"21.37228809181389",
         "lat":"42.00762790595865",
         "geometry":"{\"type\": \"Point\", \"coordinates\": [21.37228809181389,42.00762790595865]}"
      },
      "itineraries":{
         "itinerary":{
            "duration":"159000",
            "startTime":"2010-10-20T00:00:00+02:00",
            "endTime":"2010-10-20T00:02:39+02:00",
            "walkTime":"159000",
            "transitTime":"0",
            "waitingTime":"0",
            "walkDistance":"212.6496008849819",
            "elevationLost":"0.0",
            "elevationGained":"0.0",
            "transfers":"0",
            "legs":{
               "leg":{
                  "@route":"Булевар Партизански Одреди",
                  "@mode":"WALK",
                  "startTime":"2010-10-20T00:00:00+02:00",
                  "endTime":"2010-10-20T00:02:39+02:00",
                  "distance":"212.6496008849819",
                  "from":{
                     "name":"Булевар Партизански Одреди",
                     "lon":"21.373255285035548",
                     "lat":"42.00736515785779",
                     "geometry":"{\"type\": \"Point\", \"coordinates\": [21.373255285035548,42.00736515785779]}"
                  },
                  "to":{
                     "name":"Булевар Партизански Одреди",
                     "lon":"21.37228809181389",
                     "lat":"42.00762790595865",
                     "geometry":"{\"type\": \"Point\", \"coordinates\": [21.37228809181389,42.00762790595865]}"
                  },
                  "legGeometry":{
                     "length":"3",
                     "points":"_qk_GymmaCf@qC{ArI"
                  },
                  "steps":{
                     "walkSteps":{
                        "distance":"212.6496008849819",
                        "streetName":"Булевар Партизански Одреди",
                        "absoluteDirection":"EAST",
                        "stayOn":"false",
                        "becomes":"false",
                        "lon":"21.373255285035548",
                        "lat":"42.00736515785779",
                        "elevation":""
                     }
                  },
                  "duration":"159000"
               }
            },
            "tooSloped":"false"
         }
      }
   },
   "requestParameters":{
      "entry":[
         {
            "key":"optimize",
            "value":"QUICK"
         },
         {
            "key":"time",
            "value":"9:40 am\""
         },
         {
            "key":"wheelchair",
            "value":"false"
         },
         {
            "key":"maxWalkDistance",
            "value":"800.0"
         },
         {
            "key":"fromPlace",
            "value":"42.0074711701039,21.3732840843651"
         },
         {
            "key":"toPlace",
            "value":"42.0076745404488,21.3723007605583"
         },
         {
            "key":"date",
            "value":"10/20/2010"
         },
         {
            "key":"mode",
            "value":"TraverseMode (WALK, TRAM, SUBWAY, RAIL, BUS, FERRY, CABLE_CAR, GONDOLA, FUNICULAR, TRANSIT, TRAINISH, BUSISH)"
         },
         {
            "key":"numItineraries",
            "value":"3"
         }
      ]
   }
}

以下是我使用的第一部分

JSONObject planObject=json.getJSONObject("plan");
            Log.i("date",planObject.get("date").toString());

            JSONObject fromObject=planObject.getJSONObject("from");
            Log.i("from object",fromObject.get("name").toString());
            Log.i("from object",fromObject.get("stopId").toString());
            Log.i("from object",fromObject.get("lon").toString());
            Log.i("from object",fromObject.get("lat").toString());

这是菲利克斯写的例子，它是关于多个“行程”

"itineraries": [
    {"duration": "123456", ... },
    {"duration": "789012", ... }
]

这将是相同的例子，但对于一个：

"itineraries": 
{"duration": "123456", ... },

所以在第二种情况下不存在JSONArray所以如果我尝试使用菲利克斯给用于解析阵列它将返回一个错误代码。

所以问题是：什么是检查如果该值可在JSONArray放的方式。是命令optJSONArray（“possibleArrayValues”）！=使用空值或是否有更好的方法然后做大量的如果 - 则检查？

Answer 1

我不认为它的的法律的有在一个JSON对象相同名称的多个按键。即在JSON对象的键应该形成的集下，不是列表。

您可以发布一个例子，当有更多的路线？我敢打赌，它看起来是这样的：

...
"itineraries": [
    {"duration": "123456", ... },
    {"duration": "789012", ... }
]
...

如果它的确实看起来像这样，解析很容易：

JSONArray itineraries = planObject.getJSONArray("itineraries");
for (int i=0; i < itineraries.length(); i++) {
    Log.i("TAG", itineraries.getJSONObject(i).getString("duration");
}

如果没有，你正在使用的API被打破。或者修复或告诉谁运行它来解决它：）

---

编辑：现在我们知道如何在多项目反应的样子，这里是如何解析它：

Object itineraries = planObject.get("itineraries");
if (itineraries instanceof JSONObject) {
    JSONObject itinerary = (JSONObject) itineraries;
    // right now, itinerary is your single item
}
else {
    JSONArray array = (JSONArray) itineraries;
    // do whatever you want with the array of itineraries
}

未经测试，但它应该工作。