模板方法模式--Java实现

具体代码

//DBOperator.java
package org.example.test022;

public 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() {
        this.connDB();
        this.openDB();
        this.useDB();
        this.closeDB();
    }
}

//SQLServerDBOperator.java
package org.example.test022;

public class SQLServerDBOperator extends DBOperator {
    @Override
        public void connDB() {
        System.out.println("连接SqlServer数据库");
    }
}

//OracleDBOperator.java
package org.example.test022;

public class OracleDBOperator extends DBOperator {
    @Override
        public void connDB() {
        System.out.println("连接Oracle数据库");
    }
}

//Main.java
package org.example.test022;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请选择你想要连接的数据库：1、SqlServer数据库；2、Oracle数据库");
        int i = sc.nextInt();
        DBOperator connectionTemplateMethod;
        if (i == 1) {
            connectionTemplateMethod = new SQLServerDBOperator();
            connectionTemplateMethod.process();
        }
        else if (i == 2) {
            connectionTemplateMethod = new OracleDBOperator();
            connectionTemplateMethod.process();
        }
        else {
            System.out.println("没有提供这种数据库类型呦~");
        }
    }
}

运行结果