@RequestParam in Spring Boot: By default, parameters with @RequestParam annotation are required. If you fail to provide parameters to such annotated endpoints, your request will fail.
In such cases, you will have specifically mention that the parameter can sometimes be missed to make a request to your endpoint.
… we can use @RequestParam to extract query parameters, form parameters, and even files from the request.
https://www.baeldung.com/spring-request-param
@RequestParam usage
@GetMapping("/api/foos")
@ResponseBody
public String getFoos(@RequestParam String id) {
return "ID: " + id;
}Usage of @RequestParam would look something like the code snippet shown above. In the example above, if you try a GET request to the /api/foos endpoint without the parameter of String id, your request will fail.
This is because, by default, the parameter is required for your request to get successful.
Configuring @RequestParam to be optional
We can configure our @RequestParam to be optional, though, with the required attribute.
Simply set the required attribute to false as shown below:
@GetMapping("/api/foos")
@ResponseBody
public String getFoos(@RequestParam(required = false) String id) {
return "ID: " + id;
}