Is it good to use non-String type for ActionForm Property?

[Alec Lee]

I am using Struts. And, I need to gather some dollar value from text box. I prefer to use java.math.BigDecimal to represent the value in backend. Should I define the ActionForm property of type java.math.BigDecimal directly instead of String?

I know I can do this and it seems that struts can convert input parameter (String) into BigDecimal automatically. Furthermore, I can also use BigDecimal type in DynaActionForm and the similar conversion is done automatically.

But, the problem is if I input some non-numeric value in the text box which is incompatible with BigDecimal's constructor, struts throws an exception in the browser! Is there any way to catch the exception? Or, is it a good design to use BigDecimal at all?

Afterall DynaActionForm does support it and a bunch of other non-String type, so I guess there is some good reasons behind this. But, If it is a good design, there would be another problem. How can the ActionForm store the invalid input value (some non numeric character) in BigDecimal and redisplay it in the response?

[John Smith]

I find it easier to use String properties only in the ActionForms and convert back and forth to numbers in my Action classes if I need to, it makes things easier in the jsp. I think the struts tags will try to convert anything to a String anyway but if you do it yourself you can guarantee it will be done and can handle removing any excess decimal places you don't want and such