I have read in the struts documentation about 2 validators required and requiredstring.
The required validator checks whether a field value is null.
The requiredstring validator checks whether a field value is null and also whether the field value is empty.
So the required validator will not find any error if a blank value is passed as the field value but requiredstring validator will not allow blank value to be submitted.
I have the following doubt: If the required validator is anyway going to allow blank values to be submitted what is the use of this validator? Suppose I have a field named userName where the required validation is carried out.
<message>Username must not be null</message>
Under what circumstances will I get an error message?