命令模式
命令模式（Command Pattern）是一种数据驱动的设计模式，它属于行为型模式。请求以命令的形式包裹在对象中，并传给调用对象。调用对象寻找可以处理该命令的合适的对象，并把该命令传给相应的对象，该对象执行命令
实际案例
类信息概览：
| 类名 | 说明 |
|---|---|
| Main.java | 方法的总入口 |
| SellStock.java | 出售股票 |
| Order.java | 下单 |
| BuyStock.java | 购买股票 |
| Stock.java | 股票 |
| StockCommand.java | 股票命令行 |
定义
- SellStock.java
package com.ryo.design.pattern.note.command;
/**
* @author houbinbin
* @version 1.0
* @on 2017/8/13
* @since 1.7
*/
public class SellStock implements Order {
private Stock stock;
public SellStock(Stock stock) {
this.stock = stock;
}
@Override
public void execute() {
this.stock.sell();
}
}
- Order.java
package com.ryo.design.pattern.note.command;
/**
* @author houbinbin
* @version 1.0
* @on 2017/8/13
* @since 1.7
*/
public interface Order {
/**
* 执行
*/
void execute();
}
- BuyStock.java
package com.ryo.design.pattern.note.command;
/**
* @author houbinbin
* @version 1.0
* @on 2017/8/13
* @since 1.7
*/
public class BuyStock implements Order {
private Stock stock;
public BuyStock(Stock stock) {
this.stock = stock;
}
@Override
public void execute() {
this.stock.buy();
}
}
- Stock.java
package com.ryo.design.pattern.note.command;
import lombok.Data;
/**
* @author houbinbin
* @version 1.0
* @on 2017/8/13
* @since 1.7
*/
@Data
public class Stock {
private String name = "Common Stock";
private int num = 10;
public void buy() {
System.out.println("Buy "+this);
}
public void sell() {
System.out.println("Sell "+this);
}
}
- StockCommand.java
package com.ryo.design.pattern.note.command;
import java.util.LinkedList;
import java.util.List;
/**
* @author houbinbin
* @version 1.0
* @on 2017/8/13
* @since 1.7
*/
public class StockCommand {
private List<Order> orderList = new LinkedList<>();
public void addOrder(Order order) {
this.orderList.add(order);
}
public void executeOrder() {
for(Order order : this.orderList) {
order.execute();
}
}
}
测试
- Main.java
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
* Copyright (c) 2012-2018. houbinbini Inc.
* design-pattern All rights reserved.
*/
package com.ryo.design.pattern.note.command;
/**
* <p> </p>
*
* <pre> Created: 2018/5/21 下午7:27 </pre>
* <pre> Project: design-pattern </pre>
*
* @author houbinbin
* @version 1.0
* @since JDK 1.7
*/
public class Main {
public static void main(String[] args) {
Stock stock = new Stock();
BuyStock buyStock = new BuyStock(stock);
SellStock sellStock = new SellStock(stock);
StockCommand command = new StockCommand();
command.addOrder(buyStock);
command.addOrder(sellStock);
command.executeOrder();
}
}
- 测试结果
Buy Stock(name=Common Stock, num=10)
Sell Stock(name=Common Stock, num=10)
实现方式
UML & Code
UML
UML 图示如下
Code
代码地址
