ResourceAssembler doesn't get marshelled correctly when sent inside Collection

I have this ResourceAssembler to insert _link to the response:

@Component
public class UserJobResourceAssembler implements ResourceAssembler<UserJob, Resource<UserJob>>  {

	private EntityLinks entityLinks;
	
	public UserJobResourceAssembler(EntityLinks entityLinks) {
		this.entityLinks = entityLinks;
	}

	@Override
	public Resource<UserJob> toResource(UserJob entity) {
		Resource<UserJob> resource = new Resource<>(entity);
		resource.add(
				entityLinks.linkFor(UserJob.class, entity.getUser().getUniqueId()).slash(entity.getUserJobId()).withSelfRel()
				);
		
		return resource;
	}

}

This works very fine if I am having a controller which returns single Resource<UserJob>. Like below

	@GetMapping(value = "/{jobId}")
	public HttpEntity<Resource<UserJob>> getSingle(@PathVariable String uniqueId, @PathVariable int jobId) {

		return ResponseEntity.ok( userJobService.getJob(jobId) );

	}

//service
	public Resource<UserJob> getJob(Integer jobId) {		
		return jobResourceAssembler.toResource(userJobDao.findById(jobId).orElseThrow(() -> new ResourceNotFoundException("Job not found")));
	}

+++++++++++++++++++++
response:
{
    "userJobId": 32,
    "company": {
        "id": null,
        "name": "Google"
    },
    "designation": "Intern",
    "location": "Delhi",
    "started": "2016-12-31",
    "ended": "2018-07-31",
    "summary": "Intern at google ",
    "looking_job": false,
    "_links": {
        "self": {
            "href": "http://localhost:8085/api/v1/users/puspender-tanwar/jobs/32"
        }
    }
}

Notice the format of _link.

But I am having another endpoint controller which returns me all of the jobs. Those jobs data should also contain their self link. So I iterated over the collection returned by the Database and added the _links using the above ResourceAssembler

	@GetMapping
	public HttpEntity<Set<Resource<UserJob>>> getAll(@PathVariable String uniqueId) {
		
		return ResponseEntity.ok(userJobService.getJobs(uniqueId));
	}


//service
	@Override
	public Set<Resource<UserJob>> getJobs(String userUniqueId) {
		Set<UserJob> userJobs = userJobDao.findByUserUniqueId(userUniqueId, Sort.by(Sort.Direction.DESC, "started"));
		Set<Resource<UserJob>> collectionResources = new HashSet<>();
		for (UserJob userJob : userJobs) {
			Resource<UserJob> jobResource = jobResourceAssembler.toResource(userJob);
			collectionResources.add(jobResource);
		}
               return collectionResources

But the response I got this time made me confused. The format of link is not expected in this way

[
    {
        "userJobId": 32,
        "company": {
            "id": null,
            "name": "Google"
        },
        "designation": "Intern",
        "location": "Delhi",
        "started": [
            2016,
            12,
            31
        ],
        "ended": [
            2018,
            7,
            31
        ],
        "summary": "Intern at google ",
        "looking_job": false,
        "links": [
            {
                "rel": "self",
                "href": "http://localhost:8085/api/v1/users/puspender-tanwar/jobs/32",
                "hreflang": null,
                "media": null,
                "title": null,
                "type": null,
                "deprecation": null
            }
        ]
    },
   {
   //other
   }

Also, started and ended format changes to array.

What could be the real cause of this unusual behaviour?

[gregturn]

Essentially, you must return a ResourceSupport object (or one of its subtypes) to get Spring HATEOAS to render HAL.

You can always come up with your own subclass of ResourceSupport. It will produce HAL.

[Puspendert]

Thanks for the help @gregturn