java 操作MongoDB数据库

//创建了一个MongoDB的数据库连接对象，它默认连接到当前机器的localhost地址，端口是27017Mongo mongo = new Mongo(); //Mongo mongo = new Mongo("127.0.0.1", 27017);for (String name : mongo.getDatabaseNames()) {System.out.println("dbName: " + name);        }//这样就获得了一个test的数据库DB db = mongo.getDB("test");for (String name : db.getCollectionNames()) {            System.out.println("collectionName: " + name);        }BasicDBObject doc = new BasicDBObject();doc.put("name", "MongoDB");doc.put("type", "database");doc.put("count", "1");BasicDBObject info = new BasicDBObject();info.put("x", 203);info.put("y", 102);doc.put("info", info);//这样就获得了一个DBCollection，它相当于我们数据库的“表”。   获得 foo 文档DBCollection users = db.getCollection("foo");//插入数据users.insert(doc);  DBObject myDoc = users.findOne();//插入多条数据 for (int i=0; i < 100; i++) {    //users.insert(new BasicDBObject().append("i", i));   }  //获取文档数System.out.println(users.count());DBCursor cur = users.find();while(cur.hasNext()) {System.out.println(cur.next());}//查询BasicDBObject query = new BasicDBObject();   query.put("i", 71);  cur = users.find(query);while(cur.hasNext()) { System.out.println(cur.next()); }//删除i=61的项    query = new BasicDBObject();query.put("i", 61); users.findAndRemove(query);//删除数据库 //m.dropDatabase("my_new_db");