Java设计模式：策略Strategy模式，以电影票折扣策略为例

Java设计模式：策略Strategy模式，以电影票折扣策略为例

/** * 折扣策略。 * * @author zhangfly * */ public interface DiscountStrategy { public double getDiscountPrice(double value); }

 

/** * 电影票模型。 * * @author zhangfly * */ public class MovieTicket { private double price; private DiscountStrategy strategy; public void setPrice(double price) { this.price = price; } // 设置电影票打折策略。 public void setDiscountStrategy(DiscountStrategy strategy) { this.strategy = strategy; } // 原价。 public double getPrice() { return price; } // 折扣价。 public double getDiscountPrice() { // 折扣票价计算策略。 return strategy.getDiscountPrice(this.price); } }

 

/** * 学生，折扣策略：打八折。 * * @author zhangfly * */ public class StudentDiscountStrategy implements DiscountStrategy { @Override public double getDiscountPrice(double value) { return value * 0.8; } }

 

/** * VIP，电影票折扣策略半价。 * * @author zhangfly * */ public class VIPDiscountStrategy implements DiscountStrategy { @Override public double getDiscountPrice(double value) { return value * 0.5; } }

 

public class Test { public Test() { double price = 100; MovieTicket movieTicket = new MovieTicket(); movieTicket.setPrice(price); System.out.println("电影票原价: " + movieTicket.getPrice()); DiscountStrategy studentStrategy = new StudentDiscountStrategy(); movieTicket.setDiscountStrategy(studentStrategy); System.out.println("学生票价: " + movieTicket.getDiscountPrice()); DiscountStrategy vipStrategy = new VIPDiscountStrategy(); movieTicket.setDiscountStrategy(vipStrategy); System.out.println("VIP票价: " + movieTicket.getDiscountPrice()); } public static void main(String[] args) { new Test(); } }

 

输出：

电影票原价: 100.0 学生票价: 80.0 VIP票价: 50.0