param.required

Mark a parameter as required.

Resolution order

Requiredness is resolved through a three-layer chain — an explicit rule always wins, and the framework gets a say when no rule matches:

param.required rule  >  framework annotation  >  framework default

The middle layer is what makes framework semantics work without a rule. For Spring MVC, @RequestParam, @RequestHeader, @CookieValue, @PathVariable, and @RequestPart count as required unless required = false is declared, a defaultValue is supplied, or the type is Optional. A parameter with no binding annotation — including @ModelAttribute — keeps Spring's own default and stays optional.

Annotations declared on a super method are honored, so a @RequestParam(required = false) on an interface method still applies to its implementation.

Use field.required for the same semantics on model fields.

Usage

param.required=groovy:it.ann("org.springframework.web.bind.annotation.RequestParam")?.required() ?: true

Example

Use javax.validation annotations

param.required=groovy:it.hasAnn("javax.validation.constraints.NotNull")||it.hasAnn("javax.validation.constraints.NotBlank")

Use annotation rule

param.required=@javax.validation.constraints.NotNull
param.required=@javax.validation.constraints.NotBlank
param.required=@javax.validation.constraints.NotEmpty