Multiple javax.validation.constraints validations on @PathVariable

Question

I am applying multiple validations on path variable

@PathVariable(name = "id")
  @NotBlank(message = "Missing required field")
  @Size(min = 1, max = 3, message = "Invalid input size")
String id

Now, when I am sending empty string in path param then I am getting both messages because both validations are failing.

For my param id, I want both validations but it should not throw both error messages at a time when I am sending empty string.

I want it to throw only

"Missing required field"

and not both.

Answer 1

NotBlank is a combination of both functionalities that NotNull and NotEmpty validate. Therefore @NotBlank will fire both when the bound pathVariable is null and when empty.

Since you already have @Size(min = 1, max = 3, message = "Invalid input size") you are already checking if not empty. This annotation will fire at the same time with @NotBlank in case the pathVariable is empty string.

So you only need a different constraint validation for when it is null, so that the 2 annotations that enforce constraints do not override each other.

As a solution you can replace @NotBlank with @NotNull.

@PathVariable(name = "id")
  @NotNull(message = "Missing required field")
  @Size(min = 1, max = 3, message = "Invalid input size")
String id