@NotNull annotation is not enforced for @RequestParam when parameter is passed as an empty value

[selalerercapitolis]

Affects: \Spring Boot v2.3.9.RELEASE, Spring v5.2.13.RELEASE

When annotating a parameter of type Long of a controller with @NotNull for a @get method and passing the parameter as empty value, the parameter is received as null.

@RestController
@RequestMapping("testController1")
public class TestController {

    @GetMapping("testMethod1")
    public Long testMethod(@RequestParam @NotNull Long param1) {
        assertNotNull(param1);
        return param1;
    }

}

Getting 400 when requesting http://localhost:8082/testController1/testMethod1
Getting 200 when requesting http://localhost:8082/testController1/testMethod1?param1=555
Getting 500 when requesting http://localhost:8082/testController1/testMethod1?param1=&param2=bla

Expecting to 400 for the last case too.

[selalerercapitolis]

Those two seem related:
#15035
#15207

[sannnan]

facing the same issue. Does it gets resolved?
my questions:
https://stackoverflow.com/questions/72712302/notnull-or-notempty-is-not-working-as-expected-spring-boot-controller

[bclozel]

Closing as a duplicate of #16519 and #11041