spring restcontroller和responsebody返回$ ref之类的列表项

Question

我在@RestController和@ResponseBody中尝试了以下方法，但是，列表转移到屏幕上打印的损坏的json中。在下图中，可以看到userList有3个项目，包括字段id，name，mobile等。但是，在json中，最后两项变为"$ref" : "$[0].upperOpt[0].lowerOpt[12]"

结果：

修改

@Entity
public class User implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue
    private Long id;

    private String name;

    @Column(unique = true, nullable = false)
    private String mobile;

    private String email;

    @Column(nullable = false)
    private int state;

    private Date creationTime;

    private Date modificationTime;

    @Version
    private int version;

    /**
     * An operator user, and his managed companies.
     */
    @ManyToMany(mappedBy = "belongers")
    private List<CorporationInfo> managedCompany;

    /**
     * An corporation user, and his companies.
     */
    @ManyToMany(mappedBy = "admins")
    private List<CorporationInfo> myCompany;

    @ManyToMany(fetch = FetchType.LAZY)
    @JoinTable(name = "OptOpt", joinColumns = { @JoinColumn(name = "managedUserId") }, inverseJoinColumns = { @JoinColumn(name = "userId") })
    private List<User> upperOpt;

    @ManyToMany(fetch = FetchType.LAZY)
    @JoinTable(name = "OptOpt", joinColumns = { @JoinColumn(name = "userId") }, inverseJoinColumns = { @JoinColumn(name = "managedUserId") })
    private List<User> lowerOpt;

    @ManyToMany(fetch = FetchType.LAZY)
    @JoinTable(name = "UserRole", joinColumns = { @JoinColumn(name = "userId") }, inverseJoinColumns = { @JoinColumn(name = "roleId") })
    private List<Role> roleList;

    @PrePersist
    public void prePersist() {
        Date now = new Date();
        creationTime = now;
        modificationTime = now;
    }

    @PreUpdate
    public void preUpdate() {
        modificationTime = new Date();
    }
    // GETTERS AND SETTERS are left out...
    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", mobile='" + mobile + '\'' +
                ", email='" + email + '\'' +
                ", state=" + state +
                ", creationTime=" + creationTime +
                ", modificationTime=" + modificationTime +
                ", version=" + version +
                ", managedCompany=" + managedCompany +
                ", myCompany=" + myCompany +
                ", roleList=" + roleList +
                '}';
    }
}

我省略了页面null相关代码以节省空间：

 public class PageVto<T> {

        public PageVto(Page page) {
            this.page = page;
        }

        private Page page;
        public Long getTotal() {
            return page.getTotalElements();
        }
        public int getPageSize() {
            return page.getSize();
        }
        public int getPageNum() {
            return page.getNumber() +1;
        }

        public List<T> getData () {
            return page.getContent();
        }

        public void setPage(Page page) {
            this.page = page;
        }
    }