java - mongodb scala 驱动程序 casbah 是否自动管理连接池

Question

我正在使用 mongo cashbah Scala 驱动程序，我想在我的代码中使用连接池，但我不确定我的代码是否使用连接池，我也读到我们只需要创建一次 MongoClient 实例并再次重用它，所以我不确定我的代码是否重用它或每次都创建一个新实例，请指导我这是我的代码

object MongoFactory {

  val log = LoggerFactory.getLogger(this.getClass)
  val config = ConfigFactory.load()
  var client:MongoClient=null

  private var SERVER:ServerAddress = {
      val hostName=config.getString("db.hostname")
      val port=config.getString("db.port").toInt
    new ServerAddress(hostName,port)
      }    
   private var DATABASE:String   = config.getString("db.dbname")


      def createConnection: MongoClient = {
         log.info("server "+SERVER + "DATABASE" +DATABASE)

         client=MongoClient(SERVER)
         client
      }

      def getConnection : MongoClient = {
        log.debug("In method getConnection")
        if(client==null)
        {
        log.debug("mongoclient instance is null")
        client=createConnection 

        log.debug("mongoclient is {}",client)
        log.debug("Leaving method getConnection with returned value {}",client)
        client
        }
        else
        {    
         log.debug("Leaving method getConnection with returned value {}",client)
         client
        }
      }

      def getCollection(conn: MongoClient,collectionName:String): MongoCollection = {
         conn(DATABASE)(collectionName)
      }

     def closeConnection(conn: MongoClient) {
        conn.close
      }



class Abc 
{
def readAll()
{
  var connection=MongoFactory.getConnection
  var collection=MongoFactory.getCollection(connection, "User")
  val cursor=collection.find()
   while(cursor.hasNext)
     {
     // here fetching the data from database
     }  
   MongoFactory.closeConnection(connection)
}

def readById()={
  var connection=MongoFactory.getConnection
  var collection=MongoFactory.getCollection(connection, "User")
  val cursor=collection.find(q.get)
   while(cursor.hasNext)
     {
     // here fetching the data from database
     }  
   MongoFactory.closeConnection(connection)
}
}

object test extends App {
MongoFactory.getConnection

val abc=new Abc()
abc.readAll()
abc.readById()
}

我对上述代码有一些疑问

1. 此代码是否使用连接池

2. 此代码是否重用 mongoClient 实例或其创建新实例每次实例

3. 我是否需要在每次查询后关闭连接，如果不需要，则何时关闭我应该关闭连接

请指导我

更新

我对代码进行了以下更改

object MongoFactory {

  val log = LoggerFactory.getLogger(this.getClass)
  val config = ConfigFactory.load()
  var client:MongoClient=null

  private var SERVER:ServerAddress = {
      val hostName=config.getString("db.hostname")
      val port=config.getString("db.port").toInt
    new ServerAddress(hostName,port)
      }    
   private var DATABASE:String   = config.getString("db.dbname")

  val connectionMongo = MongoConnection(SERVER)
  val collectionMongo = connectionMongo(DATABASE)("artGroup")
}
class Abc 
    {
    def readAll()
    {
      val cursor=collectionMongo.find()
       while(cursor.hasNext)
         {
         // here fetching the data from database
         }  

    }

    def readById()={
      val cursor=collectionMongo.find(q.get)
       while(cursor.hasNext)
         {
         // here fetching the data from database
         }  

    }
    }

    object test extends App {

    val abc=new Abc()
    abc.readAll()
    abc.readById()
    }

此更新的代码是重用 mongo 连接还是每次都创建一个新实例，请指导我

Answer 1

请参阅此 question 。因此，每当您创建 MongoConnection 时，实际上都会在后台创建连接池。

关于您的特定代码:每次您想要获取记录时，您都会创建MongoConnection。将其分配给val，将其移至上层并一直使用它。当应用程序停止时关闭它。