ModelMapper 没有映射 Spring Entity 属性

Question

我目前正在尝试使用 ModelMapper 的 map 方法执行实体到 DTO 的映射。在最深的属性映射上，映射结果为空，但应该是一个对象。

这些是我的映射源实体（为简洁起见，省略了 Loombok Getter 和 Setter）：

public class Client implements Serializable
{       
  @Id
  @GeneratedValue(strategy=GenerationType.IDENTITY)
  public Long id;

  @NotEmpty
  public String name;

  @NotEmpty
  public String surname;

  @NotEmpty
  @Email
  public String email;

  @Column(name="creation_date", updatable=false)
  @Temporal(TemporalType.DATE)
  @DateTimeFormat(pattern="yyyy-MM-dd")
  public Date creationDate;

  public String photo;

  @OneToMany(mappedBy="client", fetch=FetchType.LAZY, cascade=CascadeType.ALL, orphanRemoval=true)
  public List<Invoice> invoices;
}

public class Invoice implements Serializable
{    
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  public Long id;

  @NotEmpty
  public String description;

  public String comment;

  @Temporal(TemporalType.DATE)
  @Column(name = "creation_date", updatable = false)
  @DateTimeFormat(pattern = "yyyy-MM-dd")
  public Date creationDate;

  @ManyToOne(fetch = FetchType.LAZY)
  public Client client;

  @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
  @JoinColumn(name = "invoice_id")
  public List<InvoiceItem> items;
}

public class InvoiceItem implements Serializable
{   
  @Id
  @GeneratedValue(strategy=GenerationType.IDENTITY)
  public Long id;

  public Integer amount;

  @ManyToOne(fetch=FetchType.EAGER) 
  @JoinColumn(name="product_id")
  public Product product;
}

public class Product implements Serializable
{   
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    public Long id;

    public String name;
    public Double prize;

    @Temporal(TemporalType.DATE)
    @Column(name="creation_date", updatable=false)
    @DateTimeFormat(pattern="yyyy-MM-dd")
    public Date creationDate;
}

这些是我的目标 DTO（为简洁起见，省略了 Loombok Getter 和 Setter）：

public class ClientDTO implements Serializable
{
    @JsonIgnore
    public Long id;

    public String name;

    public String surname;

    public String email;

    @JsonIgnore
    public Date creationDate;

    public String photo;
}

public class ClientWithInvoicesDTO extends ClientDTO implements Serializable
{
    @JsonManagedReference
    public List<InvoiceDTO> invoices;
}

public class InvoiceDTO implements Serializable
{
    @JsonIgnore
    public Long id;

    public String description;

    public String comment;

    public Date creationDate;

    @JsonBackReference
    public ClientDTO client;

    public List<InvoiceItemDTO> items;
}

public class InvoiceItemDTO implements Serializable
{
    @JsonIgnore
    public Long id;

    public Integer amount;

    public ProductDTO productDTO;   
}

public class ProductDTO implements Serializable
{
    @JsonIgnore
    public Long id;

    public String name;

    public Double prize;

    @JsonIgnore
    public Date creationDate;
}

在我的 Controller 类方法上，我正在做这样的映射：

@RequestMapping(value = "/{id}/with-invoices", method = RequestMethod.GET)
public ResponseEntity findOneWithInvoices(@PathVariable Long id)
{
    Client wantedClient = this.clientService.findOneWithInvoices(id);

    ClientWithInvoicesDTO wantedClientWithInvoicesDto = this.modelMapper.map(wantedClient, ClientWithInvoicesDTO.class);

    return new ResponseEntity<>(wantedClientWithInvoicesDto, HttpStatus.OK);
}

我的 clientService 正在正确返回数据，但 JSON 响应中的“product”属性为 null，并且不应该是：

{
    "name": "cupiditate",
    "surname": "veritatis",
    "email": "george.prohaska@example.com",
    "photo": "ec0327a5-3de8-328c-a812-9000d6d5507d",
    "invoices": [
        {
            "description": "Distinctio autem id vel necessitatibus unde omnis rerum. Minus maxime quos doloribus. Voluptatem amet praesentium sit magni quia molestiae. Officia aspernatur numquam ut perspiciatis a.",
            "comment": "Odio enim libero tempore molestiae.",
            "creationDate": "2013-02-16",
            "items": [
                {
                    "amount": 6,
                    "productDTO": null
                },
...

谁能帮我解决这个问题？

Answer 1

你不应该把@Entity 放在你的课前吗？像这样：

@Entity
public class MyClass {
...
}

Answer 2

正如M. Deinum 在下面的评论中所说，InvoiceItemDTO 产品属性应命名为“product”而不是“productDTO”。现在可以正常使用了