org.springframework.dao.InvalidDataAccessApiUsageException：传递给persist的分离实体：com.Company

Question

当我尝试运行简单测试时，我收到此错误：

org.springframework.dao.InvalidDataAccessApiUsageException：传递给persist的分离实体：com.Company;嵌套异常是org.hibernate.PersistentObjectException：传递给persist的分离实体：com.Company

我在SpringData和Hibernate中使用H2和Postgre数据库。

以下是我的实体：

@Entity
@Proxy(lazy = false)
public class Invoice {

  @ElementCollection(fetch = FetchType.EAGER)
  private List<InvoiceEntry> products = new ArrayList<>();

  @Id
  @GeneratedValue(strategy = GenerationType.TABLE)
  @Column(name = "ID", unique = true, nullable = false)
  private Long id;

  private String name;

  @JoinColumn
  @ManyToOne(cascade = CascadeType.ALL)
  private Company buyer;

  @JoinColumn
  @ManyToOne(cascade = CascadeType.ALL)
  private Company seller;

公司课程：

@Entity
@Proxy(lazy = false)
public class Company{

  @Id
  @GeneratedValue(strategy = GenerationType.TABLE)
  private Long id;
  private String name;
  private LocalDate issueDate;
  private String address;
  private String city;
  private String zipCode;
  private String nip;
  private String bankAccoutNumber;

简单测试如下：

@Test
  public void shouldAddAndGetSingleInvoice() {
    //given
    long invoiceId = database.addEntry(testInvoice);

    //when
    String output = mapper.toJson(database.getEntryById(invoiceId));
    String expected = mapper.toJson(testInvoice);

    //then
    assertThat(output, is(equalTo(expected)));
  }

尝试将级联类型更改为Merge但它不起作用。我会很感激任何建议。