How to get the value of selectManyListbox component using ParameterMap object

[Vallidevi Appana]

Hi all

I am using SelectMayListBox component in my jspx.
I want to get the value of this component which is List or array in my action class. ( Here I want this value without submitting the form so I used ParameterMap in my action class.)

  ParameterMap requestMap = ctx.getExternalContext()
.getRequestParameterMap();
AttributeMap attMap = requestMap.asAttributeMap();
(List)attMap.get("fqServiceBean:ForeignState")  

The third line in the code throwing ClassCastException. I tried to replace List with String[] then also same thing happened.
But when I put String instead List it didn't throw anything. But in this case I can get only one item selected by the user.
How can I get the list in my action class?

Thansk in advance.