I know that we can use validation framework for validating form fields (Form bean properties).
But, if I have a form bean property "items" which is an ArrayList collection of some "VO" objects where "VO.getProperty("X")" will give a form bean property, then how can I validate the "items" property?
I don't know how to add an entry in validation.xml for 'items' which is an ArrayList.
The validation.xml will take whatever values from your html's source.
If your ArrayList is given a max limit, you'll be ok; you just have to list every possibility in the validation.xml. If it's unlimited, you can't use the validation framework and you'll have to iterate and validate manually in your validate() method.