java.lang.IllegalStateException：使用@ManyToMany 3个实体对同一个实体进行多次表示 [英] java.lang.IllegalStateException: Multiple representations of the same entity with @ManyToMany 3 entities

问题描述

角色实体：

  @Entity 
公共类角色{
 
 @Id 
 @GeneratedValue（strategy = GenerationType.IDENTITY）
私人整数角色ID; 
私人字符串roleName; 
私有字符串描述; 
 
 @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 
公共类权限{
 
 @Id 
 @GeneratedValue（strategy = GenerationType.IDENTITY）
 private int permissionID; 
 private String permissionName; 
私有字符串描述; 
 
 @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 
公共类功能{
 
 @Id 
 @GeneratedValue（strategy = GenerationType.IDENTITY）
私人整数ID; 
私人字符串名称; 
  

我做了以下操作：

1. 我创建了3个功能。

    功能1，功能2，功能3 
     




2. 然后创建2个权限为：

     a。权限1与功能1，功能2。 
    
    b。权限2与功能2，功能3。 
     




3. 然后创建一个角色为：

    具有Permission1和Permission2的角色1 iam获得异常
     

   
   
   < blockquote>
   

   java.lang.IllegalStateException：正在合并同一个实体[com.persistence.entity.admin.Functionality＃1]的多个表示。独立：[com.persistence.entity.admin.Functionality@4729256a];分离：[com.persistence.entity.admin.Functionality@56ed25db]

   
   

解决方案

通过删除Permission实体上的CascadeType.MERGE来修复它。

I am having 3 entities with ManyToMany relationships as below:

Role Entity:

    @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>();

Permission Entity:

    @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<>();

Functionality Entity:

    @Entity
public class Functionality {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private String name;

I did the following:

1. I have created 3 functionalities.

   functionality1, functionality2, functionality3
   

2. Then created 2 permissions as :

   a. Permission 1 with functionality1, functionality2.
   
   b. Permission 2 with functionality2, functionality3.
   

3. Then while creating a role as:

   Role 1 with Permission1 and Permission2 iam getting following exception
   

   java.lang.IllegalStateException: Multiple representations of the same entity [com.persistence.entity.admin.Functionality#1] are being merged. Detached: [com.persistence.entity.admin.Functionality@4729256a]; Detached: [com.persistence.entity.admin.Functionality@56ed25db]

解决方案

Fixed it by removing CascadeType.MERGE on Permission entity

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