Java设计模式：策略Strategy模式，以电影票折扣策略为例

╰+攻爆jí腚メ 2023-11-23 07:08 131阅读 0赞

/**
     * 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