我有三个具有多对多关系的实体:
角色实体:
@Entity
public class Role {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer roleID;
private String roleName;
private String description;
@ManyToMany(cascade = {CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REFRESH}, fetch = FetchType.EAGER)
@JoinTable(name = "role_permission", joinColumns = {@JoinColumn(name = "role_id")}, inverseJoinColumns = {@JoinColumn(name = "permission_id")})
private Set<Permission> permissions = new LinkedHashSet<Permission>();
}
权限实体:
@Entity
public class Permission {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int permissionID;
private String permissionName;
private String description;
@ManyToMany(cascade = {CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REFRESH}, fetch = FetchType.EAGER)
@JoinTable(name = "permission_functionality", joinColumns = {@JoinColumn(name = "permission_id")}, inverseJoinColumns = {@JoinColumn(name = "functionality_id")})
private Set<Functionality> functionalities = new LinkedHashSet<>();
}
功能实体:
@Entity
public class Functionality {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String name;
}
我做了以下事情:
我创建了3个功能:
然后创建了2个权限:Functionality1, Functionality2, Functionality3
Permission1 with Functionality1, Functionality2
Permission2 with Functionality2, Functionality3
然后创建一个角色: Role1 with Permission1 and Permission2
我得到了以下异常:
java.lang.IllegalStateException:正在合并同一实体的多个表示[com.persistence.entity.admin.Functionality#1]。分离的:[com.persistence.entity.admin.Functionality@4729256a]; 分离的:[com.persistence.entity.admin.Functionality@56ed25db]
CascadeType.MERGE
会发生什么? - El Mac