我在解析JSON对象时遇到问题。 JSON表示用户下的订单。
这以前曾起作用，但是向项目中添加其他实体/ DTO导致了一些问题。更具体地说，JSON如下所示：
{
"orderElements": [
{
"product": {
"id": 3,
"name": "xxx",
"description": "yyy",
"category": {
"id": 2,
"name": "xxx"
},
"price": 11,
"count": 1
},
"quantity": 1
}
],
"user": {
"id": 110,
"lastName": "xxx",
"firstName": "xxx",
"addressLine": "xxx",
"city": "xxx",
"country": "xxx",
"zipCode": "123456",
"phoneNumber": "1234567",
"password": "xxxx",
"email": "xxxx",
"roles": [
"USER"
]
},
"orderPlaceTime": null,
"deliveryAddress": {
"street": "xxx",
"city": "xxx",
"zipCode": "xxx"
}
}
如果发送时不带“ deliveryAddress”部分，则表示JSON已正确解析，并且一切正常。但是，尝试使用“ deliveryAddress”及其所有内容发送JSON会导致NullPointerException。
尽管调试前端显示整个JSON已正确填充-street，city和zipCode字段包含用户已放置的所有数据（以上正是“ POST”发送的数据-后端填充了“ orderPlaceTime”通过LocalDateTime.now（）函数）。
@Entity
@Table(name = "carts")
public class Order extends AbstractEntity {
@Fetch(FetchMode.SELECT)
@OneToMany(cascade = CascadeType.ALL)
@JoinColumn(name = "id_order")
@JsonIgnore
private Set<OrderElement> orderElements;
@Column
private LocalDateTime orderPlaceTime;
@ManyToOne
@JoinColumn(name = "id_user")
private User user;
@ManyToOne
@JoinColumn(name = "id_delivery")
private DeliveryAddress deliveryAddress;
public DeliveryAddress getDeliveryAddress() {
return deliveryAddress;
}
public void setDeliveryAddress(DeliveryAddress deliveryAddress) {
this.deliveryAddress = deliveryAddress;
}
public Set<OrderElement> getOrderElements() {
return orderElements;
}
public void setOrderElements(Set<OrderElement> orderElements) {
this.orderElements = orderElements;
}
public LocalDateTime getOrderPlaceTime() {
return orderPlaceTime;
}
public void setOrderPlaceTime(LocalDateTime orderPlaceTime) {
this.orderPlaceTime = orderPlaceTime;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
}
@Entity
@Table(name = "delivery_address")
public class DeliveryAddress extends AbstractEntity {
@Column
private String street;
@Column
private String city;
@Column
private String zipCode;
public String getStreet() {
return street;
}
public void setStreet(String street) {
this.street = street;
}
public String getZipCode() {
return zipCode;
}
public void setZipCode(String zipCode) {
this.zipCode = zipCode;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
}
@Component
public class OrderConverter implements Converter<Order, OrderDTO> {
private final OrderElementConverter orderElementConverter;
private final DeliveryAddressConverter deliveryAddressConverter;
private final UserConverter userConverter;
public OrderConverter(OrderElementConverter orderElementConverter, DeliveryAddressConverter deliveryAddressConverter, UserConverter userConverter) {
this.orderElementConverter = orderElementConverter;
this.deliveryAddressConverter = deliveryAddressConverter;
this.userConverter = userConverter;
}
@Override
public Order convertToEntity(OrderDTO dto) {
Order order = new Order();
order.setId(dto.getId());
order.setUser(userConverter.convertToEntity(dto.getUser()));
order.setOrderPlaceTime(now());
Set<OrderElement> entitySet = new HashSet<>();
for (OrderElementDTO o : dto.getOrderElements()) {
entitySet.add(orderElementConverter.convertToEntity(o));
}
order.setOrderElements(entitySet);
// this below throws NullPointerException --> dto.getDeliveryAddressDTO();
order.setDeliveryAddress(deliveryAddressConverter.convertToEntity(dto.getDeliveryAddressDTO()));
return order;
}
}
@Component
public class DeliveryAddressConverter implements Converter<DeliveryAddress, DeliveryAddressDTO> {
@Override
public DeliveryAddress convertToEntity(DeliveryAddressDTO dto) {
DeliveryAddress deliveryAddress = new DeliveryAddress();
deliveryAddress.setId(dto.getId());
deliveryAddress.setCity(dto.getCity());
deliveryAddress.setZipCode(dto.getZipCode());
deliveryAddress.setStreet(dto.getStreet());
return deliveryAddress;
}
}
我不知道为什么前端正确发送的deliveryAddress为null。
感谢您提供所有答案和建议
事实证明，正如OrderDTO中的JB Nizet字段所指出的，该字段具有“ deliveryAddressDTO”而不是“ deliveryAddress”。从名称中删除“ DTO”可解决此问题：
public class OrderDTO extends AbstractDTO {
private Set<OrderElementDTO> orderElements;
private LocalDateTime orderPlaceTime;
private UserDTO user;
private DeliveryAddressDTO deliveryAddress;
// private DeliveryAddressDTO deliveryAddressDTO; <-- wrong name, methods also aligned
public DeliveryAddressDTO getDeliveryAddress() {
return deliveryAddress;
}
public void setDeliveryAddressDTO(DeliveryAddressDTO deliveryAddress) {
this.deliveryAddress = deliveryAddress;
}
public Set<OrderElementDTO> getOrderElements() {
return orderElements;
}
public void setOrderElements(Set<OrderElementDTO> orderElements) {
this.orderElements = orderElements;
}
public LocalDateTime getOrderPlaceTime() {
return orderPlaceTime;
}
public void setOrderPlaceTime(LocalDateTime orderPlaceTime) {
this.orderPlaceTime = orderPlaceTime;
}
public UserDTO getUser() {
return user;
}
public void setUser(UserDTO user) {
this.user = user;
}
}
答案 0 :(得分：0)
事实证明，正如OrderDTO中的JB Nizet字段所指出的，该字段具有“ deliveryAddressDTO”而不是“ deliveryAddress”。从名称中删除“ DTO”可解决此问题：
public class OrderDTO extends AbstractDTO {
private Set<OrderElementDTO> orderElements;
private LocalDateTime orderPlaceTime;
private UserDTO user;
private DeliveryAddressDTO deliveryAddress;
// private DeliveryAddressDTO deliveryAddressDTO; <-- wrong name, methods also aligned
public DeliveryAddressDTO getDeliveryAddress() {
return deliveryAddress;
}
public void setDeliveryAddressDTO(DeliveryAddressDTO deliveryAddress) {
this.deliveryAddress = deliveryAddress;
}
public Set<OrderElementDTO> getOrderElements() {
return orderElements;
}
public void setOrderElements(Set<OrderElementDTO> orderElements) {
this.orderElements = orderElements;
}
public LocalDateTime getOrderPlaceTime() {
return orderPlaceTime;
}
public void setOrderPlaceTime(LocalDateTime orderPlaceTime) {
this.orderPlaceTime = orderPlaceTime;
}
public UserDTO getUser() {
return user;
}
public void setUser(UserDTO user) {
this.user = user;
}
}
JB Nizet还解决了id_delivery问题-向ManyToOne添加层叠.ALL注释解决了所有问题。
谢谢！