Modify URL based on search filter

I have a product search page. In which I have search field. After searching the list of product is displaying in result section. Now I want to modify the search using left side panel "Refine your search" , in this section there are some parameter that will narrow your search. Let user searching Shirt then my URL is http://localhost:8080/query?q=shirt Now if user refine the result with color RED. I need to update the URL with http://localhost:8080/query?q=shirt&color=red How to do ? I am using Spring MVC and JSP , Javascript is also an option.