JPA：在三个实体之间使用多个多对多关系后，冗余的SQL插入

Question

我有用户，角色和权限实体，并将嵌入式数据库用于开发目的。 用户和角色具有多对多关系，并且角色和权限也具有多对多关系：1）用户实体：

@Entity
@Table(name = "usr")
@JsonIgnoreProperties(ignoreUnknown = true)
public class User implements Serializable {

    private static final long serialVersionUID = 818129969599480161L;
    /**
     * Unique id for the User. "@Id" declare the parameter as the primary key
     * "@GeneratedValue" indicates JPA 2 (and behind Hibernate) which strategy
     * to use for creating a new value.
     * "GenerationType.AUTO" value allow JPA implementation to use the better way depending to the RDBMS used.
     */
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;
    /**
     * Login of the user. No annotation here, the parameter will be automatically mapped in the table.
     */
    private String login;
    /**
     * Password of the user. No annotation here, the parameter will be automatically mapped in the table.
     */
    private String password;

    @ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    @JoinTable(name = "USER_ROLES",
            joinColumns =
            @JoinColumn(name = "user_id"),
            inverseJoinColumns =
            @JoinColumn(name = "role_id"))
    private Set<Role> roles = new HashSet<>();
.....(getters and setters)

2）角色实体：

@Entity
public class Role {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    private String roleName;

    @ManyToMany(mappedBy = "roles", fetch=FetchType.EAGER)
    private Set<User> users = new HashSet<>();

    @ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    @JoinTable(name = "ROLE_PERMISSION",
            joinColumns =
            @JoinColumn(name = "ROLE_ID"),
            inverseJoinColumns =
            @JoinColumn(name = "PERMISSION_ID"))
    private Set<Permission> permissions = new HashSet<>();
    .....(getters and setters)

3）许可实体：

    @Entity
    public class Permission {
        @Id
        @GeneratedValue(strategy = GenerationType.AUTO)
        private int id;
        private String permissionName;

        @ManyToMany(mappedBy = "permissions", fetch=FetchType.EAGER, cascade = {})
        private Set<Role> roles = new HashSet<>();
    .....(getters and setters)

并因为我的测试填充器：

public void afterPropertiesSet() throws Exception {
    _logger.debug("setting test uses data");

    Permission permission = new Permission();
    permission.setPermissionName("PERM_SAVE_PRODUCT");

    permissionRepository.save(permission);

    Role role = new Role();
    role.setRoleName("ROLE_ADMIN");
    Set<Permission> permissions = new HashSet<>();
    permissions.add(permission);
    role.setPermissions(permissions);

    roleRepository.save(role);

    User user = new User();
    user.setLogin("dmitro");
    user.setPassword("2424");
    user.setStatus(UserStatus.ACTIVE);
    Set<Role> roles = new HashSet<Role>();
    roles.add(role);
    user.setRoles(roles);

    userRepository.save(user);
}

我希望创建一个用户记录， 一个角色记录和一个权限记录，并将其插入到详细信息存储库中。 一切看起来都很干净（没有任何异常），但是clien告诉我，我有两个角色记录和三个权限记录，例如：

{
"links": [
],
"content": [
    {
        "links": [
            {
                "rel": "roles.Role.permissions",
                "href": "http://localhost:8080/admin/roles/1/permissions"
            },
            {
                "rel": "self",
                "href": "http://localhost:8080/admin/roles/1"
            },
            {
                "rel": "roles.Role.users",
                "href": "http://localhost:8080/admin/roles/1/users"
            }
        ],
        "roleName": "ROLE_ADMIN"
    },
    {
        "links": [
            {
                "rel": "roles.Role.permissions",
                "href": "http://localhost:8080/admin/roles/2/permissions"
            },
            {
                "rel": "self",
                "href": "http://localhost:8080/admin/roles/2"
            },
            {
                "rel": "roles.Role.users",
                "href": "http://localhost:8080/admin/roles/2/users"
            }
        ],
        "roleName": "ROLE_ADMIN"
    }
],
"page": {
    "size": 20,
    "totalElements": 2,
    "totalPages": 1,
    "number": 1
}

}

在日志中，我看到所有内容都已创建，但是为什么我还不知道为什么，请提供帮助。 日志在这里： https : //www.dropbox.com/s/orx3c9p023bxmti/log.txt?dl=0

Answer 1

您正在分别保存用户，角色，权限。 这将导致多个记录。 由于您已给出Cascade，因此所有保存的用户对象也将保存角色对象和权限对象。

这样尝试

public void afterPropertiesSet() throws Exception {
_logger.debug("setting test uses data");

User user = new User();
user.setLogin("dmitro");
user.setPassword("2424");
user.setStatus(UserStatus.ACTIVE);
Set<Role> roles = new HashSet<Role>();
Role role = new Role();
role.setRoleName("ROLE_ADMIN");
Set<Permission> permissions = new HashSet<>();
Permission permission = new Permission();
permission.setPermissionName("PERM_SAVE_PRODUCT");
permissions.add(permission);
role.setPermissions(permissions);
roles.add(role);
user.setRoles(roles);
userRepository.save(user);

}

在这里看到有关层叠的信息 。 希望能帮助到你