No TemplateVariable generated for null Pageable [DATACMNS-1752]

[spring-projects-issues]

Réda Housni Alaoui opened DATACMNS-1752 and commented

We use:

• Spring Data Commons 2.3.0
• Spring Data JPA 2.3.0
• Spring HATEOAS 1.1.0

HateoasPageableHandlerMethodArgumentResolver is registered in the Spring context.

Given the following controller:

 @Controller
  @RequestMapping("/")
  public static class MyController {

    private final WebMvcLinkBuilderFactory webMvcLinkBuilderFactory;

    public MyController(WebMvcLinkBuilderFactory webMvcLinkBuilderFactory) {
      this.webMvcLinkBuilderFactory = webMvcLinkBuilderFactory;
    }

    @GetMapping
    public ResponseEntity<?> links() {
      return ResponseEntity.ok(
          new RepresentationModel<>(
              Collections.singletonList(
                  webMvcLinkBuilderFactory
                      .linkTo(methodOn(MyController.class).pageable(null))
                      .withRel("pageable"))));
    }

    @GetMapping("/pageable")
    public ResponseEntity<?> pageable(Pageable pageable) {
      return ResponseEntity.noContent().build();
    }
}

Querying / with accept: application/hal+json produces:

{
  "_links": {
    "pageable": {
      "href": "http://localhost/pageable"
    }
  }
}

We were expecting the link to be templated with the following optional variables:

• page
• size

The issue on the Spring HATEOAS side is https://github.com/spring-projects/spring-hateoas/issues/706

How to fix that?

---

Affects: 2.3.1 (Neumann SR1)

[reda-alaoui]

Please note that https://github.com/spring-projects/spring-hateoas/issues/706 can be fixed by applying https://github.com/spring-projects/spring-hateoas/pull/1312 . After that, a pull request inspired by https://github.com/Cosium/spring-data-commons/commit/b9600b18b8bd94fefb10ef85ee0c72ff9b4225c0 fixes the current issue.