Struts setting a String object instead of Integer in the form

Hi,

Getting the below exception after a form is submitted. The form has a check box, when this check box is not selected we get the exception. If the check box is selected it works normally. Is there 
anything I should be doing to force struts to put a Integer value in the hash map when the check box is not selected?

  Exception: java.lang.ClassCastException: class java.lang.String cannot be cast to class java.lang.Integer (java.lang.String and java.lang.Integer are in module java.base of loader 'bootstrap')


The code line where it happens is below

                 else if(getEnrollmentForm().getCapDeferral().get(compID) != null && getEnrollmentForm().getCapDeferral().get(compID)==1) {

Variable Declaration:
     @Element(value=java.lang.Integer.class)
     private HashMap<Long, Integer> capDeferral = new HashMap<Long,Integer>();

Struts Version: 7.2.1  have tested it with 7.3.0 and same result.

Appreciate your help.

Thanks,
Prasanth