Spring Data Paging and Sorting Repository not deleting data - spring

Question

So all I'm trying to do is allow users to delete their own comments and posts in my application, and I have a form that's supposed to run a controller method that should delete it, but it's not working.
I'll show you my controller and repository to show you guys what I'm trying to do.
So here's my Controller method
#RequestMapping(value="userEdits/editComment/{commentId}/deleteComment", method=RequestMethod.POST)
public String deleteComment (#PathVariable Long commentId, #AuthenticationPrincipal User user)
{
Comment comment = commentRepo.findOne(commentId);
User savedUser = userRepo.findUserByUsername(user.getUsername());
savedUser.getCourses().remove(comment);
commentRepo.delete(comment);
return "redirect:/userEdits";
}
And I can even run this in debug mode and see that the right comment is in the commentRepo.delete(comment); line. And it runs all the through and returns the userEdits screen, just like it should, without any errors, but the comment is still there after it runs through everything.
Here's my repository class, it's pretty simple, but who knows, I could be missing something.
public interface CommentRepository extends PagingAndSortingRepository <Comment, Long>{
public Page<Comment> findByPostOrderByIdDesc(Post post, Pageable pageable);
public List<Comment> findByUserOrderByIdDesc(User user);
}
I'm confused because this should be a simple task and it appears that it's running through and returning the view I tell it to, without error.
So if anyone can see where I'm going wrong that would be great. Thanks in advance.
UPDATE
User Entity
#Entity
#Table(name = "users")
#JsonIdentityInfo(generator = ObjectIdGenerators.IntSequenceGenerator.class, property = "#id")
public class User {
private Long id;
#ValidEmail
#NotNull
#NotEmpty
private String email;
private String username;
private String password;
private University university;
private Set<Authorities> authorities = new HashSet<>();
private Set<Course> courses = new HashSet<>();
private Set<Post> posts = new HashSet<>();
private Set<Comment> comments = new HashSet<>();
private Set<StudySet> studySet = new HashSet<>();
private Set<Course> myCourses = new HashSet<Course>();
public User() {
}
public User(User user) {
this.id = user.getId();
this.email = user.getEmail();
this.username = user.getUsername();
this.password = user.getPassword();
this.university = user.getUniversity();
this.authorities = user.getAuthorities();
this.courses = user.getCourses();
this.posts = user.getPosts();
this.comments = user.getComments();
this.studySet = user.getStudySet();
this.myCourses = user.getMyCourses();
}
#Id
#GeneratedValue
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "user", orphanRemoval = true)
public Set<Course> getCourses() {
return courses;
}
public void setCourses(Set<Course> courses) {
this.courses = courses;
}
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "user", orphanRemoval = true)
public Set<Post> getPosts() {
return posts;
}
public void setPosts(Set<Post> posts) {
this.posts = posts;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
#ManyToOne
public University getUniversity() {
return university;
}
public void setUniversity(University university) {
this.university = university;
}
#OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "user")
#JsonManagedReference
#JsonIgnoreProperties(allowGetters = true, value = "user")
public Set<Comment> getComments() {
return comments;
}
public void setComments(Set<Comment> comments) {
this.comments = comments;
}
#OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "user")
public Set<Authorities> getAuthorities() {
return authorities;
}
public void setAuthorities(Set<Authorities> authorities) {
this.authorities = authorities;
}
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "user", orphanRemoval = true)
public Set<StudySet> getStudySet() {
return studySet;
}
public void setStudySet(Set<StudySet> studySet) {
this.studySet = studySet;
}
#ManyToMany(cascade = { CascadeType.ALL }, fetch = FetchType.EAGER)
#JoinTable(name = "user_myCourses")
public Set<Course> getMyCourses() {
return myCourses;
}
public void setMyCourses(Set<Course> myCourses) {
this.myCourses = myCourses;
}
}
Comment Entity
#Entity
#JsonIdentityInfo(generator = ObjectIdGenerators.IntSequenceGenerator.class, property = "#id")
public class Comment {
public Long id;
#Size(min = 1, max = 140)
public String comment;
public Post post;
public User user;
#Temporal(TemporalType.DATE)
#DateTimeFormat(pattern = "dd-MMM-YYYY")
private LocalDate date;
#Temporal(TemporalType.TIME)
#DateTimeFormat(pattern = "HH:mm:ss")
private LocalTime time;
#Temporal(TemporalType.DATE)
#DateTimeFormat(pattern = "MM/dd/yyyy HH:mm:ss")
private LocalDateTime dateTime;
public Comment() {
}
#Id
#GeneratedValue
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
#Size(min = 1, max = 140)
public String getComment() {
return comment;
}
public void setComment(String comment) {
this.comment = comment;
}
#ManyToOne
public Post getPost() {
return post;
}
public void setPost(Post post) {
this.post = post;
}
#ManyToOne
#JsonBackReference
#JsonIgnoreProperties(value = { "comments" }, allowGetters = true)
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public LocalDate getDate() {
return date;
}
public void setDate(LocalDate date) {
this.date = date;
}
public LocalTime getTime() {
return time;
}
public void setTime(LocalTime time) {
this.time = time;
}
public LocalDateTime getDateTime() {
return dateTime;
}
public void setDateTime(LocalDateTime dateTime) {
this.dateTime = dateTime;
}
#Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((id == null) ? 0 : id.hashCode());
return result;
}
#Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Comment other = (Comment) obj;
if (id == null) {
if (other.id != null)
return false;
} else if (!id.equals(other.id))
return false;
return true;
}
public Comment(Long id, String comment, Post post, User user, LocalDate date, LocalDateTime dateTime) {
this.id = id;
this.comment = comment;
this.post = post;
this.user = user;
this.date = date;
this.dateTime = dateTime;
}
}
UPDATE
So I realized I needed to addorphanRemoval = true to the comment of the user, now I get the error the entity must not be null when I run the controller method, however it does delete the comment. But I need my app to run the method and return the view I ask it to, without the error message popping up.

Answer 1

The problem is in your CascadeType. You've specified:
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "user", orphanRemoval = true)
CascadeType.ALL means that comments are managed by user entity and you can't delete comment directly. You should read about cascade types and change it for your needs or you have orphanRemoval = true so you can simply save user after deletion and comment should be deleted for example
savedUser.getCourses().remove(comment);
userRepo.save(savedUser);