MongoCollection<Document> collection = mongoClient.getDatabase(dbName).getCollection(collName);
需要通过获取这个连接 来调用
String[] ids = new String[] {"rekoe","rk"};
MongoCollection<Document> collection = moclient.getDatabase("dbName").getCollection("collName");
Bson userFilter = Filters.in("_id", ids);
collection.find(userFilter);