How to parse a JSON with dynamic “key” in android by using GSON
android, gson
Solution
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:
class Something {
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()`:
class Something {
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>`.
class ArrayOfObjectsToMapDeserializer
implements JsonDeserializer<Map<String, String>> {
public Map<String, String> deserialize(JsonElement json, Type typeOfT,
JsonDeserializationContext context) throws JsonParseException {
Map<String, String> result = new HashMap<String, String>();
JsonArray array = json.getAsJsonArray();
for (JsonElement element : array) {
JsonObject object = 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 = new GsonBuilder();
builder.registerTypeAdapter(
new TypeToken<Map<String, String>>() {}.getType(),
new ArrayOfObjectsToMapDeserializer());
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.
Problem
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":"\u51b7\u76d8,\u9ad8\u811a\u676f,\u6211\u7684\u7cd6\u679c\u5c4b,\u670d\u52a1\u4e1a\u6d88\u8d39\u52b5" }, { "\u7f8e\u5986":"\u4e2a\u62a4|\u5316\u5986#\u9762\u90e8\u62a4\u7406,\u4e2a\u4eba\u536b\u751f,\u8eab\u4f53\u62a4\u7406,\u9999\u6c34\u9999\u6c1b,\u6c90\u6d74|\u7f8e\u53d1\u7528\u54c1,\u5f69\u5986,\u7cbe\u6cb9SPA,\u773c\u90e8\u62a4\u7406,\u78e8\u7802\u53bb" }, { "\u8863\u670d":"\u670d|\u9970|\u978b|\u5e3d#\u670d\u88c5,\u978b\u9774,\u5185\u8863,\u914d\u9970,\u536b\u8863,\u4f11\u95f2\u88e4,T\u6064,\u88d9\u5b50,\u886c\u886b,\u9488\u7ec7\u886b,\u5a74\u5e7c\u513f\u670d\u9970" } ], "total":3 } ``` The key fields are dynamic, so I don't know how to write a model class to read this.