Question

I am having a jsp page on which i am having textbox,textarea and a combobox. while getting the values in Filter from request I want to know whether it is textrarea or so on. So is it possible? also in filter can i change the values of request?

Answer 1

A filter is a servlet. You can get and change values of parameters from a request just as well as in the usual servlet.

public class CheckFilter implements Filter {

    public void init(FilterConfig filterConfig) {
    }

    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain)
            throws IOException, ServletException {

       HttpServletRequest request = (HttpServletRequest) req;

       String contentTextarea = request.getParameter("myTextarea");

       String modifyContentTextarea = changeContent(contentTextarea);

       chain.doFilter(request, response);
    }

    private String changeContent(String content) {
          //to do smth with value of content
          return modifyContent;
    }

    public void destroy() {
    }
}

And mark your textarea in JSP like this:

<textarea name="myTextarea"></textarea>