策略+适配器模式详解

1.策略模式

1.目录结构

2.Strategy.java 策略接口

package com.sunxiansheng.design_pattern.strategy;/*** Description: 策略接口** @Author sun* @Create 2025/2/7 12:17* @Version 1.0*/
public interface Strategy {/*** 算法接口*/void algorithmInterface();
}

3.StrategyA.java 策略A

package com.sunxiansheng.design_pattern.strategy;/*** Description: 策略A** @Author sun* @Create 2024/8/12 20:05* @Version 1.0*/
public class StrategyA implements Strategy{@Overridepublic void algorithmInterface() {System.out.println("策略A");}
}

4.StrategyB.java 策略B

package com.sunxiansheng.design_pattern.strategy;/*** Description: 策略B** @Author sun* @Create 2024/8/12 20:05* @Version 1.0*/
public class StrategyB implements Strategy{@Overridepublic void algorithmInterface() {System.out.println("策略B");}
}

5.StrategyC.java 策略C

package com.sunxiansheng.design_pattern.strategy;/*** Description: 策略C** @Author sun* @Create 2024/8/12 20:05* @Version 1.0*/
public class StrategyC implements Strategy{@Overridepublic void algorithmInterface() {System.out.println("策略C");}
}

6.Context.java 策略上下文

package com.sunxiansheng.design_pattern.strategy;/*** Description: 策略上下文，根据不同的策略执行不同的算法** @Author sun* @Create 2025/2/7 12:17* @Version 1.0*/
public class Context {/*** 策略的属性*/private Strategy strategy;/*** 在创建对象的时候就指定不同的策略* @param type*/public Context(int type) {switch (type) {case 1:strategy = new StrategyA();break;case 2:strategy = new StrategyB();break;case 3:strategy = new StrategyC();break;default:break;}}/*** 调用具体的算法*/public void contextInterface() {strategy.algorithmInterface();}
}

7.Client.java 客户端

package com.sunxiansheng.design_pattern.strategy;/*** Description: 客户端** @Author sun* @Create 2025/2/7 12:19* @Version 1.0*/
public class Client {public static void main(String[] args) {// 策略工厂中定义具体的策略Context context = new Context(1);// 调用方法时，就会指定具体的策略context.contextInterface();}
}

8.小结

策略模式，首先要定义一个策略接口，然后每个具体的策略都要去实现这个策略接口，接下来就要有一个上下文，这个上下文可以根据不同的类型来设置不同的策略。

2.适配器模式

1.目录结构

2.CustomPaymentProcessor.java 自己的支付接口

package com.sunxiansheng.design_pattern.adapter;/*** Description: 自定义的支付接口** @Author sun* @Create 2025/2/9 11:05* @Version 1.0*/
public interface CustomPaymentProcessor {void processPayment(double amount);
}

3.PayPalPaymentService.java 第三方的支付服务

package com.sunxiansheng.design_pattern.adapter;/*** Description: 第三方支付服务（需要适配的接口）** @Author sun* @Create 2025/2/9 11:06* @Version 1.0*/
public class PayPalPaymentService {public void makePayment(double amountInDollars) {System.out.println("Payment made using PayPal: $" + amountInDollars);}
}

4.PayPalPaymentAdapter.java 第三方适配器

package com.sunxiansheng.design_pattern.adapter;/*** Description: 适配器类，用来将第三方的PayPal支付接口适配到系统自定义的支付接口上** @Author sun* @Create 2025/2/9 11:07* @Version 1.0*/
public class PayPalPaymentAdapter implements CustomPaymentProcessor {/*** 注入第三方接口*/private PayPalPaymentService payPalPaymentService;public PayPalPaymentAdapter(PayPalPaymentService payPalPaymentService) {this.payPalPaymentService = payPalPaymentService;}/*** 将第三方接口适配，使其满足自己接口的要求** @param amount*/@Overridepublic void processPayment(double amount) {System.out.println("适配过的接口");payPalPaymentService.makePayment(amount);}
}

5.Client.java 客户端

package com.sunxiansheng.design_pattern.adapter;/*** Description: 客户端** @Author sun* @Create 2025/2/9 11:08* @Version 1.0*/
public class Client {public static void main(String[] args) {// 第三方的支付ServicePayPalPaymentService payPalPaymentService = new PayPalPaymentService();// 自己的适配器聚合第三方支付PayPalPaymentAdapter payPalPaymentAdapter = new PayPalPaymentAdapter(payPalPaymentService);// 使用适配器调用方法payPalPaymentAdapter.processPayment(100.0);}
}

6.小结

适配器模式其实就是自己有一个接口，然后第三方有一个服务，就需要一个适配器，这个适配器就需要实现自己的接口，然后聚合第三方的接口，来完成自己接口的对应功能。