How To Parse A Json With Dynamic “key” In Android By Using Gson

I have been using GSON library to parse all the json string and get a JSON object. But now I need to parse is like this: { 'status':1, 'info':[ { '\u5a31\u4e50

Solution 1:

How would you like your model class to look?

status and total would probably be int, so that only leaves info.

As an experiment, just add a field Object info and see how Gson would set it to an ArrayList<LinkedHashMap<String, String>> -- ugly and hard to access by key, but all the data is there. Given that information, the fastest way to model a class would be:

classSomething{
  int status;
  List<Map<String, String> info;
  int total;
}

If you have control over how that JSON is generated, I suggest changing the structure of info from an array of objects [{a:b},{c:d},{e:f}] to just an object {a:b,c:d,e:f}. With this, you could just map it to a Map<String, String> with all the benefits like access by key, keys() and values():

classSomething{
  int status;
  Map<String, String> info;
  int total;
}

If you want the latter model class without changing the JSON format, you'll have to write a TypeAdapter (or JsonDeserializer if you're only interested in parsing JSON, not generating it from your model class).

Here's a JsonDeserializer hat would map your original info JSON property to a plain Map<String, String>.

classArrayOfObjectsToMapDeserializerimplementsJsonDeserializer<Map<String, String>> {

  publicMap<String, String> deserialize(JsonElement json, Type typeOfT,
      JsonDeserializationContext context) throws JsonParseException {
    Map<String, String> result = newHashMap<String, String>();

    JsonArray array = json.getAsJsonArray();
    for (JsonElement element : array) {
      JsonObjectobject = element.getAsJsonObject();
      // This does not check if the objects only have one property, so JSON// like [{a:b,c:d}{e:f}] will become a Map like {a:b,c:d,e:f} as well.for (Entry<String, JsonElement> entry : object.entrySet()) {
        String key = entry.getKey();
        String value = entry.getValue().getAsString();
        result.put(key, value);
      }
    }
    return result;
  }
}

You need to register this custom JsonDeserializer similar to this:

GsonBuilder builder = newGsonBuilder();
builder.registerTypeAdapter(
    newTypeToken<Map<String, String>>() {}.getType(),
    newArrayOfObjectsToMapDeserializer());
Gson gson = builder.create();

Note that this registers the custom deserializer for any Map<String, String> regardless in what class it is encountered. If you don't want this, you'll need to create a custom TypeAdapterFactory as well and check the declaring class before returning and instance of the deserializer.

Solution 2:

Here goes a solution, which does not requires to make a JsonDeserializer.

All you can create is a JsonElement in a map Map.Entry<String, JsonElement>and use a for loop to iterate over the entries

//parsing string response to json objectJsonObjectjsonObject= (JsonObject) newJsonParser().parse(jsonString);
//getting root objectJsonObjectdateWiseContent= jsonObject.get("rootObject").getAsJsonObject();
    
for (Map.Entry<String, JsonElement> entry : dateWiseContent.entrySet()) {      
    //this gets the dynamic keysStringdateKey= entry.getKey();
            
    //you can get any thing now json element,array,object according to json.JsonArrayjsonArrayDates= entry.getValue().getAsJsonArray();
}

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