使用jdbc在java中創建單例連接對象

Question

我正在嘗試使用單例設計模式創建一個連接對象。這是正確的做法嗎？ 請幫助我以適當的方式執行此操作。

package com.cisco.installbase.hiveconnector;

import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Connection;


public class CreateConnection {

        private static Connection connection = null;
        static final String drivername = "org.apache.hive.jdbc.HiveDriver";
        private static CreateConnection instance;

        private CreateConnection() {

            try{
                Class.forName(drivername);
                connection = DriverManager.getConnection("jdbc:hive2://hddev-c01-edge-01:50045/","phodisvc","B1GD4T4dev");
            }catch(ClassNotFoundException e){
                e.printStackTrace();
            } catch (SQLException e) {
                e.printStackTrace();
            }

    }

        public static CreateConnection getInstance()
        {
            if(instance == null)
            {
                instance = new CreateConnection();
            }

            return instance;
        }
}

Answer 1

以我的例子為例。 （只需將 URL、用戶名和密碼替換為您的）

public class DatabaseConnection {

public static Connection con = null;

public static void dbConnect(String drv, String url, String usr, String pwd) {

    // CHARGEMENT DU PILOTE
    try {
        Class.forName(drv);
    } catch (ClassNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    // CONNEXION BDD
    try {
        con = DriverManager.getConnection(url, usr, pwd);
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

}