@Component
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter(){
        return new ServerEndpointExporter();
    }
}

@Service
@Slf4j
public class OrderServiceImpl implements OrderService {
    @Autowired
    private ProductService productService;
    @Autowired
    private OrderDetailRepository orderDetailRepository;
    @Autowired
    private WebSocket webSocket;
	
    @Override
    @Transactional
    public OrderDTO create(OrderDTO orderDTO) {
        String orderId= KeyUtil.genUniqueKey();
        BigDecimal orderAmount=new BigDecimal(BigInteger.ZERO);
//        List<CartDTO> cartDTOList=new ArrayList<>();
        //1.查询商品（数量，价格）
        for(OrderDetail orderDetail:orderDTO.getOrderDetailList()){
            ProductInfo productInfo=productService.findOne(orderDetail.getProductId());
            if(productInfo==null){
//                throw new SellException(ResultEnum.PRODUCT_NOT_EXIT);
                throw new ResponseBankException();
            }
            //2.计算订单总价
            orderAmount=productInfo.getProductPrice()
                    .multiply(new BigDecimal(orderDetail.getProductQuantity()))
                    .add(orderAmount);
            //订单详情入库
            orderDetail.setDetailId(KeyUtil.genUniqueKey());
            orderDetail.setOrderId(orderId);
            BeanUtils.copyProperties(productInfo,orderDetail);
            orderDetailRepository.save(orderDetail);
//            CartDTO cartDTO=new CartDTO(orderDetail.getProductId(),orderDetail.getProductQuantity());
//            cartDTOList.add(cartDTO);
        }
        //3，写入订单数据库（orderMaster和orderDetail)
        OrderMaster orderMaster=new OrderMaster();
        orderDTO.setOrderId(orderId);
        BeanUtils.copyProperties(orderDTO,orderMaster);
//        orderMaster.setOrderId(orderId);
        orderMaster.setOrderAmount(orderAmount);
        orderMaster.setOrderStatus(OrderStatusEnum.NEW.getCode());
        orderMaster.setPayStatus(PayStatusEnum.WAIT.getCode());
        orderMasterRepository.save(orderMaster);
        //4.扣库存
        List<CartDTO> cartDTOList=orderDTO.getOrderDetailList().stream().map(e->
                new CartDTO(e.getProductId(),e.getProductQuantity()))
                .collect(Collectors.toList());
        productService.decreaseStock(cartDTOList);
        //发送websocket消息
        webSocket.sendMessage(orderDTO.getOrderId());
        return orderDTO;
    }

@Component
@ServerEndpoint("/webSocket")
@Slf4j
public class WebSocket {
    private Session session;
    private static CopyOnWriteArraySet<WebSocket> webSocketSet=new CopyOnWriteArraySet<>();
    @OnOpen
    public void onOpen(Session session){
        this.session=session;
        webSocketSet.add(this);
        log.info("【websocket消息】 有新的连接，总数：{}",webSocketSet.size());
    }
    @OnClose
    public void onClose(){
        webSocketSet.remove(this);
        log.info("【websocket消息】 连接断开，总数：{}",webSocketSet.size());
    }
    @OnMessage
    public void onMessage(String message){
        log.info("【websocket消息】 收到客户端发来的消息：{}",message);
    }
    public void sendMessage(String message){
        for(WebSocket webSocket:webSocketSet){
            log.info("【websocket消息】 广播消息，message={}",message);
            try {
                webSocket.session.getBasicRemote().sendText(message);
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}