<dependencies>
    <!-- Spring Boot Starter Web, 數(shù)據(jù) JPA, 安全性等 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>
    <!-- PayPal SDK -->
    <dependency>
        <groupId>com.paypal.sdk</groupId>
        <artifactId>paypal-java-sdk</artifactId>
        <version>1.14.0</version>
    </dependency>
</dependencies>

paypal.client.id=YOUR_CLIENT_ID
paypal.client.secret=YOUR_CLIENT_SECRET
paypal.mode=sandbox

import com.paypal.api.payments.Payment;
import com.paypal.base.rest.APIContext;
import com.paypal.base.rest.PayPalRESTException;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

@Service
public class PaymentService {

    @Value("${paypal.client.id}")
    private String clientId;

    @Value("${paypal.client.secret}")
    private String clientSecret;

    @Value("${paypal.mode}")
    private String mode;

    public String createPayment(Double total) {
        APIContext context = new APIContext(clientId, clientSecret, mode);
        // 設(shè)置支付參數(shù)
        // 這里簡(jiǎn)化了支付的設(shè)置過(guò)程，具體需要設(shè)置金額、貨幣、支付方式等
        Payment createdPayment = new Payment();
        try {
            createdPayment = createdPayment.create(context);
            return createdPayment.getLinks().stream()
                .filter(link -> link.getRel().equalsIgnoreCase("approval_url"))
                .findFirst()
                .map(link -> link.getHref())
                .orElse(null);
        } catch (PayPalRESTException e) {
            e.printStackTrace();
            return null;
        }
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class PaymentController {

    @Autowired
    private PaymentService paymentService;

    @PostMapping("/pay")
    public String pay(@RequestParam Double amount) {
        return paymentService.createPayment(amount);
    }
}

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-amqp</artifactId>
</dependency>

spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest

import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class PaymentMessageSender {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    public void sendPaymentSuccess(String paymentDetails) {
        rabbitTemplate.convertAndSend("paymentExchange", "paymentRoutingKey", paymentDetails);
    }
}

@Component
public class PaymentMessageReceiver {

    @Autowired
    private OrderService orderService;

    public void receiveMessage(String paymentDetails) {
        orderService.updateOrderStatus(paymentDetails, "PAID");
        // 還可以添加更多的處理邏輯
    }
}

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

spring.redis.host=localhost
spring.redis.port=6379

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

@Service
public class CacheService {

    @Autowired
    private RedisTemplate<String, Object> redisTemplate;

    public void cacheOrderDetails(String orderId, Order order) {
        redisTemplate.opsForValue().set("order:" + orderId, order);
    }

    public Order getOrderDetailsFromCache(String orderId) {
        return (Order) redisTemplate.opsForValue().get("order:" + orderId);
    }
}

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class LoggingAspect {

    @Pointcut("execution(* com.example.service.PaymentService.createPayment(..))")
    public void paymentOperation() {}

    @Before("paymentOperation()")
    public void logBeforePayment(JoinPoint joinPoint) {
        System.out.println("Attempting to perform a payment operation: " + joinPoint.getSignature().getName());
    }
}