Java optional parameters

Question

How do I use optional parameters in Java? What specification supports optional parameters?

Answer 1

If it's an API endpoint, an elegant way is to use "Spring" annotations:

@GetMapping("/api/foos")
@ResponseBody
public String getFoos(@RequestParam(required = false, defaultValue = "hello") String id) { 
    return innerFunc(id);
}

Notice in this case that the innerFunc will require the variable, and since it's not api endpoint, can't use this Spring annotation to make it optional. Reference: https://www.baeldung.com/spring-request-param