Java 连接MongoDB并进行insert delete操作

private static final String IP = "localhost";private static final int PORT = 27017;public static MongoClient getInstance() {return new MongoClient(IP, PORT);}public static void main(String args[]) {try {// 连接到 mongodb 服务MongoClient mongoClient = MongoUtils.getInstance();// 连接到数据库MongoDatabase db = mongoClient.getDatabase("test");System.out.println("Connect to database successfully");MongoCollection dbc=db.getCollection("Order");Document doc=new Document();//insert keydoc.put("name", "hello");doc.put("age", "24");doc.put("time", "2015-01-30");dbc.insertOne(doc);//del key//dbc.deleteOne(doc);System.out.println("总记录数>>"+dbc.count());} catch (Exception e) {System.err.println(e.getClass().getName() + ": " + e.getMessage());}}