MongoDb

• gson
• Mongo-java-driver

Gson va permettre de sérialiser et désérialiser pour passer d'objet java à JSON et inversement :

public class DBOAdapter {
	private static Gson gson;

	private static Gson getGson() {
		if (gson == null) {
			GsonBuilder gsonBuilder = new GsonBuilder();
			gsonBuilder.registerTypeAdapter(ObjectId.class, new ObjectIdAdapter());
			gsonBuilder.excludeFieldsWithoutExposeAnnotation().setDateFormat("MMMM dd, yyyy HH:mm:ss");
			gson = gsonBuilder.create();
		}
		return gson;
	}

	public static <T extends Model> T dboToModel(DBObject dbObject, Class<T> clazz) {
		gson = getGson();
		String json = gson.toJson(dbObject);
		return gson.fromJson(json, clazz);
	}

	public static BasicDBObject objectToDBObject(Object object) {
		BasicDBObject obj = (BasicDBObject) JSON.parse(getGson().toJson(object));
		return obj;
	}

	public static DBObject[] objectToDBObjectArray(Object object) {
		BasicDBObject[] objects = new BasicDBObject[] { objectToDBObject(object) };
		return objects;
	}
}

public class ObjectIdAdapter
		implements JsonSerializer<ObjectId>, JsonDeserializer<ObjectId> {

	@Override
	public JsonElement serialize(ObjectId id, Type typeOfT, JsonSerializationContext context) {
		JsonObject jo = new JsonObject();
		jo.addProperty("$oid", id.toHexString());
		return jo;
	}

	@Override
	public ObjectId deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
		try {
			return new ObjectId(json.getAsJsonObject().get("$oid").getAsString());
		} catch (Exception e) {
			return null;
		}
	}

}