建设网站话术,连云港做网站优化,推广咨询,电子商务网站建设大二实训场景与技术栈
场景#xff1a;电商系统中的订单创建流程#xff0c;涉及订单服务#xff08;Order Service#xff09;、库存服务#xff08;Inventory Service#xff09;、支付服务#xff08;Payment Service#xff09;。
技术栈#xff1a; Java 11 Spring Bo…
场景与技术栈
场景电商系统中的订单创建流程涉及订单服务Order Service、库存服务Inventory Service、支付服务Payment Service。
技术栈 Java 11 Spring Boot 2.7.0 MySQL 8.0 RabbitMQ
项目结构与组件 order-service inventory-service payment-service saga-coordinator
代码实现
1. Saga Coordinator
SpringBootApplicationpublic class SagaCoordinatorApplication { public static void main(String[] args) { SpringApplication.run(SagaCoordinatorApplication.class, args); }}ServiceRequiredArgsConstructorpublic class SagaService { private final SagaOrderService sagaOrderService; private final SagaInventoryService sagaInventoryService; private final SagaPaymentService sagaPaymentService; private final SagaTransactionRepository sagaTransactionRepository; public void placeOrder(Long orderId, Long productId, int quantity, double amount) throws ExecutionException, InterruptedException { SagaTransaction transaction new SagaTransaction(); transaction.setOrderId(orderId); transaction.setProductId(productId); transaction.setQuantity(quantity); transaction.setAmount(amount); transaction.setStatus(SagaTransaction.Status.INITIATED); sagaTransactionRepository.save(transaction); CompletableFuture.runAsync(() - sagaOrderService.createOrder(transaction)) .thenRunAsync(() - sagaInventoryService.decreaseInventory(transaction)) .thenRunAsync(() - sagaPaymentService.charge(transaction)) .exceptionally(ex - { rollback(transaction); throw new RuntimeException(Saga failed, ex); }); } private void rollback(SagaTransaction transaction) { CompletableFuture.runAsync(() - sagaPaymentService.refund(transaction)) .thenRunAsync(() - sagaInventoryService.increaseInventory(transaction)) .thenRunAsync(() - sagaOrderService.cancelOrder(transaction)) .exceptionally(ex - { transaction.setStatus(SagaTransaction.Status.FAILED); sagaTransactionRepository.save(transaction); throw new RuntimeException(Rollback failed, ex); }); }}
2. SagaOrderService
Servicepublic class SagaOrderService { private final OrderService orderService; private final RabbitTemplate rabbitTemplate; Autowired public SagaOrderService(OrderService orderService, RabbitTemplate rabbitTemplate) { this.orderService orderService; this.rabbitTemplate rabbitTemplate; } public void createOrder(SagaTransaction transaction) { // 创建订单逻辑 // ... // 发送创建订单完成的消息 rabbitTemplate.convertAndSend(order.create, transaction); } public void cancelOrder(SagaTransaction transaction) { // 取消订单逻辑 // ... // 发送取消订单完成的消息 rabbitTemplate.convertAndSend(order.cancel, transaction); }}
3. SagaInventoryService
Servicepublic class SagaInventoryService { private final InventoryService inventoryService; private final RabbitTemplate rabbitTemplate; Autowired public SagaInventoryService(InventoryService inventoryService, RabbitTemplate rabbitTemplate) { this.inventoryService inventoryService; this.rabbitTemplate rabbitTemplate; } public void decreaseInventory(SagaTransaction transaction) { // 扣减库存逻辑 // ... // 发送扣减库存完成的消息 rabbitTemplate.convertAndSend(inventory.decrease, transaction); } public void increaseInventory(SagaTransaction transaction) { // 增加库存逻辑 // ... // 发送增加库存完成的消息 rabbitTemplate.convertAndSend(inventory.increase, transaction); }}
4. SagaPaymentService
Servicepublic class SagaPaymentService { private final PaymentService paymentService; private final RabbitTemplate rabbitTemplate; Autowired public SagaPaymentService(PaymentService paymentService, RabbitTemplate rabbitTemplate) { this.paymentService paymentService; this.rabbitTemplate rabbitTemplate; } public void charge(SagaTransaction transaction) { // 收款逻辑 // ... // 发送收款完成的消息 rabbitTemplate.convertAndSend(payment.charge, transaction); } public void refund(SagaTransaction transaction) { // 退款逻辑 // ... // 发送退款完成的消息 rabbitTemplate.convertAndSend(payment.refund, transaction); }}
SagaTransaction Entity
Entitypublic class SagaTransaction { Id GeneratedValue(strategy GenerationType.IDENTITY) private Long id; private Long orderId; private Long productId; private int quantity; private double amount; private Status status; // INITIATED, COMPLETED, ROLLING_BACK, ROLLED_BACK, FAILED // Getters Setters}
消息队列监听
在每个微服务中需要添加消息队列的监听器以便在接收到消息时执行相应的操作。例如在order-service中
Componentpublic class OrderSagaListener { private final SagaOrderService sagaOrderService; Autowired public OrderSagaListener(SagaOrderService sagaOrderService) { this.sagaOrderService sagaOrderService; } RabbitListener(queues order.create) public void handleOrderCreate(SagaTransaction transaction) { sagaOrderService.createOrder(transaction); } RabbitListener(queues order.cancel) public void handleOrderCancel(SagaTransaction transaction) { sagaOrderService.cancelOrder(transaction); }}
额外细节 为确保事务的一致性可以使用RabbitMQ的发布确认Publisher Confirms机制。 每个微服务的数据库事务应该使用Transactional注解来保证ACID属性。 需要设计失败重试和事务状态检查机制确保在故障恢复时能够正确地执行补偿操作。
通过上述设计SAGA模式与RabbitMQ的结合不仅能够处理跨服务的事务还能够通过消息队列实现服务解耦和消息的异步处理提高系统的稳定性和可扩展性。
