介绍防止递归查询的两种方式

#懒加载配置
spring.jpa.properties.hibernate.enable_lazy_load_no_trans=true

@Entity
@Table(name = "users")
//@JsonIgnoreProperties("roles")
public class User implements Serializable {
 @GeneratedValue(strategy = GenerationType.IDENTITY)
 @Id
 private int id;
 @Column
 private String name;
 @Column(name = "created_at")
 @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
 private Date createdAt;
 @ManyToOne
 @JoinColumn(name = "dep_id")
 @JsonBackReference //防止关系对象的递归访问
 private Department department;
 @ManyToMany(cascade = {}, fetch = FetchType.EAGER)
 @JoinTable(name = "user_role", joinColumns = {@JoinColumn(name = "user_id")}, inverseJoinColumns = {@JoinColumn(name = "role_id")})
 @JsonBackReference
 private List<Role> roles = new ArrayList<>();
 ......
}