how not to consider #NotBlank in some methods - spring-boot

Question

I'm doing a restful app in Spring boot,jpa,mysql. I have annoted some of my model fields #NotBlank to print an error in the creation of an object if those fields are blank.
Now when i'm updating, I don't want to get that error if I don't set some fields in my json body.My goal is to update just the fields which are present.
So I want to know if there is a way not to consider an #NotBlank in my updating method.
This is the code source :
For the Entity
public class Note implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#NotBlank(name)
private String title;
#NotBlank
private String content;
//Getters and Setters
}
The controller
#RestController
#RequestMapping("/api")
public class NoteController {
#Autowired
NoteRepository noteRepository;
// Create a new Note
#PostMapping("/notes")
public Note createNote(#Valid #RequestBody Note note) {
return noteRepository.save(note);
}
// Update a Note
#PutMapping("/notes/{id}")
public Note partialUpdateNote(#PathVariable(value = "id") Long noteId,
#RequestBody Note noteDetails) {
Note note = noteRepository.findById(noteId)
.orElseThrow(() -> new ResourceNotFoundException("Note", "id", noteId));
//copyNonNullProperties(noteDetails, note);
if(note.getTitle()!= null) {
note.setTitle(noteDetails.getTitle());
}else {
note.setTitle(note.getTitle());
}
if(note.getContent()!= null) {
note.setContent(noteDetails.getContent());
}else {
note.setContent(note.getContent());
}
Note updatedNote = noteRepository.save(note);
return updatedNote;
}
// Delete a Note
#DeleteMapping("/notes/{id}")
public ResponseEntity<?> deleteNote(#PathVariable(value = "id") Long noteId) {
Note note = noteRepository.findById(noteId)
.orElseThrow(() -> new ResourceNotFoundException("Note", "id", noteId));
noteRepository.delete(note);
return ResponseEntity.ok().build();
}
}
ResourceNotFoundException is the class responsible to throws errors.

Answer 1

You can use groups for that.
Add two interfaces CreateGroup and UpdateGroup.
Use them by this way:
#NotBlank(groups = CreateGroup.class)
#Null(groups = UpdateGroup.class)
private String title;
In the create endpoint
#Valid #ConvertGroup(from = Default.class, to = CreateGroup.class) Note note
In the update endpoint
#Valid #ConvertGroup(from = Default.class, to = UpdateGroup.class) Note note
Probably you don't need UpdateGroup. It is just to show a common approach.
Also for the nested objects inside Note something like
#ConvertGroup(from = CreateGroup.class, to = UpdateGroup.class)
can be used.