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设计模式-命令模式

news 2025/7/3 11:48:58

一、所用到的类

一个接受者类：里面有N个方法
一个命令接口：里面有一个命令方法，目的是用来执行接收者的命令
N个命令实现类：目的是封装接收者的N个方法
一个调用类：用来将N个命令类通过add的方式添加到一起并通过接口中的那个方法来执行。

二、实现代码

接收者类

public class Stock {private String name = "ABC";private int quantity = 10;public void buy() {System.out.println("Stock [ Name: "+name+", Quantity: " + quantity +" ] bought");}public void sell() {System.out.println("Stock [ Name: "+name+", Quantity: " + quantity +" ] sold");}
}

命令接口

public interface Order {void execute();
}

封装接收者方法的第一个类

public class BuyStock implements Order{private Stock abcStock;public BuyStock(Stock abcStock){this.abcStock = abcStock;}@Overridepublic void execute() {abcStock.buy();}
}

封装接收者方法的第二个类

public class SellStock implements Order{private Stock abcStock;public SellStock(Stock abcStock){this.abcStock = abcStock;}@Overridepublic void execute() {abcStock.sell();}
}

聚合类

public class Broker {private List<Order> orderList = new ArrayList<>();public void takeOrder(Order order){orderList.add(order);}public void placeOrders(){for (Order order : orderList) {order.execute();}orderList.clear();}
}

调用类

@SpringBootApplication
public class CommandApplication {public static void main(String[] args) {Stock stock = new Stock();Order buyStock = new BuyStock(stock);Order sellStock = new SellStock(stock);Broker broker = new Broker();broker.takeOrder(buyStock);broker.takeOrder(sellStock);broker.placeOrders();}
}