2024.12.13

abstract class DBOperator{

    public abstract void connDB();

    public void openDB(){

        System.out.println("打开数据库");

    }

    public void useDB(){

        System.out.println("使用数据库");

    }

    public void closeDB(){

        System.out.println("关闭数据库");

    }

    public void process(){

        connDB();

        openDB();

        useDB();

        closeDB();

    }

}

class OracleDBOperator extends DBOperator{

    @Override

    public void connDB() {

        System.out.println("连接Oracle数据库");

    }

}

 

class SQLServerDBOperator extends DBOperator{

 

    @Override

    public void connDB() {

        System.out.println("连接SQL Server数据库");

    }

}

 

public class App

{

    public static void main(String[] args) {

        DBOperator operator;

        operator = new SQLServerDBOperator();

        operator.process();

        System.out.println("------------------");

        operator = new OracleDBOperator();

        operator.process();

    }

}