CODEWITHSUNDEEP
javaspringhibernatespring-data-jpa
jobcrazy
jobcrazy

Reputation: 1073

UnsupportedOperationException when updating cascading children in Spring+JPA

I'm using OneToMany mapping in my SpringBoot project, while I'm having problems when updating the children along with parent update, sample code is like below:

User.java

@Table(name = "user")
@Entity
public class User {
    @Id
    @GeneratedValue
    private Integer id;

    @OneToMany(mappedBy = "groupUser", cascade = {CascadeType.ALL}, orphanRemoval = true)
    private List<UserGroup> userGroups = new ArrayList<>();
}

UserGroup.java

@Table(name = "user_group")
@Entity
public class UserGroup {
    @Id
    @GeneratedValue
    private Integer id;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name="user_id")
    private User groupUser; 
}

SampleUsageCode.java

    @Service
    public class UserService {
        @Autowired
        private UserRepository userRepositry;

        @Transactaional
        public batchUpdateUsers(Collection<User> toBeSavedUsers) {
            Map<Integer, User> toBeSavedIdUserMap = toBeSavedUsers.stream()
.collect(groupBy(User::getId(), toList()));
            Collection<User> existingUsers = userRepositry.findByIdIn(toBeSavedIdUserMap.entrySet().stream()
.map(Map.Entry::getKey).collect(toList()));
            existingUsers.forEach(user -> user.getUserGroups().add(toBeSavedIdUserMap.get(user.getId()).getUserGroups()));
        }
    }

To simplify the problem, Let's just assume the user groups in to-be-saved users is totally different with the existing ones in the database. The problem is when I try to add new user groups to existing users, it throws java.lang.UnsupportedOperationException. It seems the persistentBag type of userGroups in User is not editable. I tried with just creating a new collection to store both existing and new user groups, but another error with A collection with cascade="all-delete-orphan" was no longer referenced by the owning entity instance occurs when I try to save the updated users. How can I achieve this cascading-children merge requirement?

Upvotes: 3

Views: 4809

Answers (1)

jobcrazy
jobcrazy

Reputation: 1073

So the problem is caused by that the user groups list I prepared for the test is Unmodifiable

Upvotes: 6

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