I am using struts and the ValidatorPlugIn. I am having some issues trying to validate input for an options box. I have the validation working correctly if within the struts-config.xml file the form-property type="java.lang.String" (I can validate the form-property value in the example listed below).
My issue is that I can't validate when the form-property is of type="java.lang.String" (I can't validate the form-property assets in the example listed below). Do I need to include something in the validation.xml that indicates I am working with type="java.lang.String"
Try using the "indexedListProperty" of the field attribute.
Extract from validator DTD file:
<!-- The "field" element defines the properties to be validated. In a web application, a field would also correspond to a control on a HTML form. To validate the properties, the validator works through a JavaBean representation. The field element can accept up to 4 attributes:
property The property on the JavaBean corresponding to this field element.
depends The comma-delimited list of validators to apply against this field. For the field to succeed, all the validators must succeed.
page The JavaBean corresponding to this form may include a page property. Only fields with a "page" attribute value that is equal to or less than the page property on the form JavaBean are processed. This is useful when using a "wizard" approach to completing a large form, to ensure that a page is not skipped. 
indexedListProperty The "indexedListProperty" is the method name that will return an array or a Collection used to retrieve the list and then loop through the list performing the validations for this field.
subject: Struts Validation of options box (java.lang.String)