Java与Scala的两种简易版连接池

import java.sql.Connection;

import java.sql.DriverManager;

import java.util.LinkedList;

/**

 * 简易版的连接池

 */

public class ConnectionPool {

    //静态的Connection

    private static LinkedList<Connection>connections;

    //加载驱动

    static {

        try {

            Class.forName("com.mysql.jdbc.Driver");

        } catch (ClassNotFoundException e) {

            e.printStackTrace();

        }

    }

    //获取连接   多线程访问并发问题控制

    public  synchronized static Connection getConnectoin(){

        try {

            if (connections==null){

                connections=new LinkedList<Connection>();

                for (int i =0;i<10;i++){

                    Connection conn=DriverManager.getConnection(

                            "jdbc:mysql://localhost:3306/spark",

                            "username",

                            "password"

                    );

                    connections.push(conn);

                }

            }

        }catch (Exception e){

            e.printStackTrace();

        }

        return connections.poll();

    }

    /**

     * 还连接

     * 返回连接

     */

    public static void returnConnection(Connection conn){

        connections.push(conn);

    }

}

object ConnectionPoolUtil {

  /**

    * 需要设置的连接池数据

    */

  private val max=10//连接池总数

  private val connectionNum=10//每次产生连接数

  private val pool=new util.LinkedList[Connection]()

  private var conNum=0//当前连接池已经产生的连接数

  //获取连接

  def getConnections(): Connection ={

    //同步代码块

    AnyRef.synchronized({

      //加载驱动

      for(i<-1 to connectionNum){

        val conn = DriverManager.getConnection(

          "jdbc:mysql://localhost:3306/spark",

          "username",

          "password"

        )

        pool.push(conn)

        conNum+=1

      }

      pool.poll()

    })

  }

  //加载驱动

  def GetConn(): Unit ={

    //控制加载

    if (conNum<max && pool.isEmpty){

      Class.forName("com.mysql.jdbc.mysql.")

    }else if(conNum>=max&&pool.isEmpty){

      println("Jdbc Pool had no connection now,please wait a moments")

      Thread.sleep(2000)

      GetConn()

    }

  }

  //还连接

  def returnConn(conn:Connection): Unit ={

    pool.push(conn)

  }

}