Seata的 TCC 模式

@Override
@GlobalTransactional(name="createOrder",rollbackFor=Exception.class)
public Order saveOrder(OrderVo orderVo) {
    log.info("=============用户下单=================");
    log.info("当前 XID: {}", RootContext.getXID());
 
    //获取全局唯一订单号  测试使用
    Long orderId = UUIDGenerator.generateUUID();
 
    //阶段一： 创建订单
    Order order = orderService.prepareSaveOrder(orderVo,orderId);
 
    //扣减库存
    storageFeignService.deduct(orderVo.getCommodityCode(), orderVo.getCount());
    //扣减余额
    accountFeignService.debit(orderVo.getUserId(), orderVo.getMoney());
 
    return order;
}

/**
 *
 * 通过 @LocalTCC 这个注解，RM 初始化的时候会向 TC 注册一个分支事务。
 */
@LocalTCC
public interface OrderService {
 
    /**
     * TCC的try方法：保存订单信息，状态为支付中
     *
     * 定义两阶段提交，在try阶段通过@TwoPhaseBusinessAction注解定义了分支事务的 resourceId，commit和 cancel 方法
     *  name = 该tcc的bean名称,全局唯一
     *  commitMethod = commit 为二阶段确认方法
     *  rollbackMethod = rollback 为二阶段取消方法
     *  BusinessActionContextParameter注解 传递参数到二阶段中
     *  useTCCFence seata1.5.1的新特性，用于解决TCC幂等，悬挂，空回滚问题，需增加日志表tcc_fence_log
     */
    @TwoPhaseBusinessAction(name = "prepareSaveOrder", commitMethod = "commit", rollbackMethod = "rollback", useTCCFence = true)
    Order prepareSaveOrder(OrderVo orderVo, @BusinessActionContextParameter(paramName = "orderId") Long orderId);
 
    /**
     *
     * TCC的confirm方法：订单状态改为支付成功
     *
     * 二阶段确认方法可以另命名，但要保证与commitMethod一致
     * context可以传递try方法的参数
     *
     * @param actionContext
     * @return
     */
    boolean commit(BusinessActionContext actionContext);
 
    /**
     * TCC的cancel方法：订单状态改为支付失败
     * 二阶段取消方法可以另命名，但要保证与rollbackMethod一致
     *
     * @param actionContext
     * @return
     */
    boolean rollback(BusinessActionContext actionContext);
}

@Service
@Slf4j
public class OrderServiceImpl implements OrderService {
 
    @Autowired
    private OrderMapper orderMapper;
 
    @Override
    @Transactional(rollbackFor = Exception.class)
    public Order prepareSaveOrder(OrderVo orderVo,
                                  @BusinessActionContextParameter(paramName = "orderId") Long orderId) {
 
        // 保存订单
        Order order = new Order();
        order.setId(orderId);
        order.setUserId(orderVo.getUserId());
        order.setCommodityCode(orderVo.getCommodityCode());
        order.setCount(orderVo.getCount());
        order.setMoney(orderVo.getMoney());
        order.setStatus(OrderStatus.INIT.getValue());
        Integer saveOrderRecord = orderMapper.insert(order);
        log.info("保存订单{}", saveOrderRecord > 0 ? "成功" : "失败");
 
        return order;
    }
 
    @Override
    public boolean commit(BusinessActionContext actionContext) {
 
 
        // 获取订单id
        long orderId = Long.parseLong(actionContext.getActionContext("orderId").toString());
        //更新订单状态为支付成功
        Integer updateOrderRecord = orderMapper.updateOrderStatus(orderId, OrderStatus.SUCCESS.getValue());
        log.info("更新订单id:{} {}", orderId, updateOrderRecord > 0 ? "成功" : "失败");
 
        return true;
    }
 
    @Override
    public boolean rollback(BusinessActionContext actionContext) {
 
        //获取订单id
        long orderId = Long.parseLong(actionContext.getActionContext("orderId").toString());
        //更新订单状态为支付失败
        Integer updateOrderRecord = orderMapper.updateOrderStatus(orderId, OrderStatus.FAIL.getValue());
        log.info("更新订单id:{} {}", orderId, updateOrderRecord > 0 ? "成功" : "失败");
 
        return true;
    }
 
 
}