Question

这是我的 orderservice 实现，用于在此处创建和保存带有 customerid 的订单，我正在让客户和客户有一个购物车，购物车中的产品列表在那里，对于该产品列表，我应该创建一个订单。

public Order save(int custid) {
        Optional<Customer> cust = customerRepo.findById(custid);//here customer is there and inside customer cart is there inside cart medicine list is there.
        Cart ct= cust.get().getCart();//getting cart from customer
        if(ct.getMedicineList().size()!=0) {//create order only if the medicine list is not empty. there are 8 fields **orderDate,dispatchDate,status,medicineList,totalCost,customer and orderId(GeneratedValue)** I can't set the orderId cuz it is auto generated.
            LocalDate todaysDate = LocalDate.now();
            LocalDate dispatchdate = todaysDate.plusDays(3);
            List<Medicine> orderList= new ArrayList<Medicine>();
            List<Medicine> cartList= new ArrayList<Medicine>();
            cartList=ct.getMedicineList();
            orderList.addAll(cartList);
            Order ord = new Order();
            ord.setCustomer(cust.get());
            ord.setMedicineList(orderList);
            ord.setDispatchDate(dispatchdate);
            ord.setOrderDate(todaysDate);
            ord.setStatus("Placed");
            ord.setTotalCost((float)ct.getTotalAmount());
            logger.info("Add order to the database");
            return orderRepository.save(ord);
        }
        return null;
        
    }

这是我的订单控制器

@PostMapping("/order/{custid}")
    public ResponseEntity<Order> addOrder(@Valid @PathVariable("custid") int custid) {
        logger.info("Add order in database");
        return new ResponseEntity<>(orderService.save(custid), HttpStatus.OK);
    }

这是我的药实体

@Data
@RequiredArgsConstructor
@ToString
@Table(name = "medicine")
@Entity
public class Medicine {
    @Id
    @Column(name = "medicine_id", nullable = false)
    @NonNull
    @GeneratedValue
    private int medicineId;
    
    @NonNull
    @Size(min = 3, message = "Minimum charecters in medicine name should be 3.")
    @NotEmpty
    @Column(unique = true, name = "medicine_name", nullable = false)
    
    private String medicineName;
    
    @NonNull
    @Column(name = "medicine_cost", nullable = false)
    private float medicineCost;
    
    @NonNull
    @Column(name = "mfd", nullable = false)
    private LocalDate mfd;
    
    @NonNull
    @Column(name = "expiry_date", nullable = false)
    private LocalDate expiryDate;
    
    @NonNull
    @Column(name = "medicine_quantity", nullable = false)
    private int medicineQuantity = 1;
    @NonNull
    private String medicineCategory;
    @NonNull
    private String medicineDescription;



    @JsonIgnore
    @ManyToMany(cascade = CascadeType.ALL, mappedBy = "medicineList",fetch = FetchType.EAGER)
    private List<Order> orderList;
}

这是我的订单实体

@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString

    public class Order {
        @Id
        @Column(name = "orderId")
        @GeneratedValue
        private int orderId;
        @NonNull
        private LocalDate orderDate;
        @ManyToMany(targetEntity = Medicine.class, cascade = CascadeType.ALL, fetch = FetchType.EAGER)
        @JoinTable(name = "ord_med", joinColumns = { @JoinColumn(name = "ord_id") }, inverseJoinColumns = {
                @JoinColumn(name = "med_id") })
        private List<Medicine> medicineList = new ArrayList<>();
        @NonNull
        private LocalDate dispatchDate;
        @NotEmpty
        private float totalCost;
        @NonNull
        private String status;
        
        @ManyToOne(cascade = CascadeType.ALL)
        @JoinColumn(name="c_ord_fk",referencedColumnName = "customerId")
        @NonNull
        private Customer customer;
        
    }

在这里，当我尝试为购物车内的列表创建订单时，它给了我 [36m.mmaExceptionHandlerExceptionResolver[0;39m [2m:[0;39m Resolved [org.springframework.transaction.TransactionSystemException: could not commit] JPA 交易；嵌套异常是 javax.persistence.RollbackException：提交事务时出错] 我不确定，但我认为这是因为 id 但它是自动生成的。不知道如何为产品列表创建订单对象，或者这是正确的方法。

Answer 1

其实我找到了答案，我所要做的就是当你使用ManyToMany映射级联类型必须是cascade = {CascadeType.MERGE,CascadeType.REFRESH}而不是{cascade = CascadeType。 ALL}，它工作正常。参考 JPA: detached entity passed to persist: nested exception is org.hibernate.PersistentObjectException

org.springframework.transaction.TransactionSystemException: 无法提交 JPA 事务；嵌套异常是 javax.persistence.RollbackException

1 个答案: