Spring请求参数的自定义验证

Question

I've exposed a rest service that accepts value_param as a request parameter. If the url param is not spelt correctly then the following exception is thrown:

Whitelabel Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.
Tue Sep 15 10:57:54 IST 2020
There was an unexpected error (type=Bad Request, status=400).
Required String parameter 'value_param' is not present

I'm attempting to explicitly check the parameter. This parameter check is in combination with other checks and any validation check fails, throw a 422 error.

Here is the endpoint signature:

   @GetMapping("/values")
    public List<ValueEntity> getValues(@RequestParam(name = "value_param") String valueParameter) {

How to access the value_param parameter and prevent the Error page with status 400 being thrown ?

Answer 1

Mark the field as @RequestParam(required = false) in the controller.
For more detailed examples could be seen: here