策略模式的思想的经典案例分析

周末也要写八哥2026-04-24 19:33

我们先来假设一个场景：作为杂货店老板，你还需要根据不同季节或促销活动选择不同的定价策略。比如在淡季时，货物打9折销售。大批量采购时，提供85折优惠。

实际上，这就是策略模式的思想。

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// 定义策略接口
interface PricingStrategy {
    double calculatePrice(double originalPrice);
}

// 定义具体策略
class SeasonalDiscountStrategy implements PricingStrategy {
    @Override
    public double calculatePrice(double originalPrice) {
        return originalPrice * 0.9; // 10% discount
    }
}

class BulkPurchaseDiscountStrategy implements PricingStrategy {
    @Override
    public double calculatePrice(double originalPrice) {
        return originalPrice * 0.85; // 15% discount
    }
}

// 上下文
class GroceryStore {
    private PricingStrategy pricingStrategy;

    public GroceryStore(PricingStrategy strategy) {
        this.pricingStrategy = strategy;
    }

    public double calculateFinalPrice(double originalPrice) {
        return pricingStrategy.calculatePrice(originalPrice);
    }
}

// 使用示例
public class Main {
    public static void main(String[] args) {
        PricingStrategy seasonalDiscount = new SeasonalDiscountStrategy();
        PricingStrategy bulkPurchaseDiscount = new BulkPurchaseDiscountStrategy();

        GroceryStore store = new GroceryStore(seasonalDiscount);
        double finalPrice = store.calculateFinalPrice(100.0);
        System.out.println("Final price with seasonal discount: " + finalPrice);

        store = new GroceryStore(bulkPurchaseDiscount);
        finalPrice = store.calculateFinalPrice(10000.0);
        System.out.println("Final price with bulk purchase discount: " + finalPrice);
    }
}

运行程序，输出如下：

复制代码

Final price with seasonal discount: 90.0
Final price with bulk purchase discount: 8500.0

好了，本文到这里就结束了，希望认真阅读全文的小伙伴，都能有所收获哦！