Play Framework 2.3.8 ManyToMany关系和YAML

Question

提前感谢您阅读本文。我现在正试图解决我的问题一个多星期，但找不到解决方案。

我正在尝试通过YAML文件填充我的ManyToMany关系，但由于某种原因它不起作用。

她是我的班级：

@Entity
public class Company extends Model {

@Id
public Integer id;

@ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.PERSIST)
@JsonManagedReference
public Set<Language> languages = new TreeSet<Language>();


@Entity
public class Language extends Model {

@Id
public Integer id;
public String  name;

@ManyToMany(mappedBy = "languages", cascade = CascadeType.PERSIST)
@JsonBackReference
public Set<Company> companies = new TreeSet<Company>();

YAML：

 - &language1 !!models.Language
    id: 1
    name: English


- &language2 !!models.Language
    id: 2
    name: Mandarin


- &language3 !!models.Language
    id: 3
    name: Cantonese


- &company1 !!models.Company
    id: 1
    languages:
      ? *language1
      ? *language2
      ? *language3

- &company2 !!models.Company
    id: 2
    languages:
      ? *language1
      ? *language3

- &company3 !!models.Company
    id: 3
    languages:
      ? *language1
      ? *language3

全局：

public class Global extends GlobalSettings {
@Override
public void onStart(Application app) {
    // Check if the database is empty
    if (User.find.findRowCount() == 0) {
        Ebean.save((List) Yaml.load("initial-data1.yml"));
    }
  }
}

当我尝试在Json中获取公司对象时，语言Set为空。

感谢您的帮助！