I have this entity:

@Entity
public class Rating {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private Boolean isNa = false;
    private String comment = "";
    @Min(0)
    @Max(5)
    private Integer points;
    @ManyToOne
    @JoinColumn(name="audit_id", nullable=false)
    private Audit audit;
    @ManyToOne
    @JoinColumn(name="question_id", nullable=false)
    private Question question;
    // ....

}

when I perform a JsonPatch in a PatchMapping, the fields autdit and question are set to null, which in turn ensures that I cannot save the rating.

Here is my PatchMapping:

    @PatchMapping("/api/v1/ratings/{id}")
    public ResponseEntity<Rating> updateRating(@PathVariable("id") long id, @RequestBody JsonMergePatch patch) throws ChangeSetPersister.NotFoundException, JsonPatchException, JsonProcessingException {
        Rating entity = findRatingService.findRatingById(id).orElseThrow(ChangeSetPersister.NotFoundException::new);
        JsonNode entityJsonNode = objectMapper.convertValue(entity, JsonNode.class);
        JsonNode patchedEntityJsonNode = patch.apply(entityJsonNode);
        Rating patchedEntity = objectMapper.treeToValue(patchedEntityJsonNode, Rating.class);
        Rating updatedEntity = saveRatingService.saveRating(patchedEntity);
        return ResponseEntity.ok(updatedEntity);
    }

patchedEntity.audit is allways null

My Example Request Body:

[
    {
        "op": "replace",
        "value": "foo",
        "path": "/comment"
    }
]

I have also tried slightly modified forms in the controller. But I am slightly stuck here and would appreciate any advice.

I’ve tried JsonPatch instead of JsonMergePatch