Java Bean验证号码格式问题

Question

I am struggling with Bean Validation to validate a Double attribute.

My application uses AngularJS with Java EE (JAX-RS / JAXB) for the backend.

My class looks like:

public class MyClass {

  @NotNull
  Double value;

  // empty constructor, getters, setters

}

If I either send to the server, the JSON representation of MyClass as :

{ value: '' }

Or

{ value: '456q' }

I end up with a validation constraint violation for value "must not be null".

I would have liked a validation constraint for type formatting issue for the second JSON representation.

Is there any way to do it beside client side validation?

Answer 1

The value that you are sending are of string type. Try sending

{ value: 456 }

Now it's a number and validation should work fine.

Answer 2

That's because your JSON is sent as string, then casted as Double (using something like Double.valueOf("456q") ), and javax.validation does not have the knowledge of that string.

However, it is still checked as a number (null is returned in invalid case).

If you really want to do a format check, then you should probably store the value as a String, and cast it as a Double when needed.