public class CheckOnly implements ServletWorker{

    private static RequestParser reqParser;
    private static ViewGenerator viewGenerator;

    public CheckOnly()
        throws Exception{
        reqParser = RequestParser.getInstance();
        viewGenerator = ViewGenerator.getInstance();
    }

    public void work(HttpServletRequest req,
                     HttpServletResponse res)
        throws NestedException,SimpleException{
        try{
            // Parse the HTTP request ...
            ParsedRequestParameters params
               = reqParser.parseSimple(req);

            // Verify all the request parameters by just
            // a single line !
            // The second parameter of this method specifies
            // the XML that is used to verify the request
            // parameters.
            VerifyResult result = viewGenerator.verify(params,0);

            // Insert the values between the tags.
            Map values = new HashMap();
            values.put("date",(new Date()).toString());

           if(result.isAllOk()){
                // If all the request parameters are valid ...
                // The second parameter of this method specifies
                // the XML that is used to generate the response.
                viewGenerator.
                    writeResponseWithDefault(params,1,res,null,
                                             values,true);
            }
            else{
                // If any of the request parameters are invalid ...
                // The second parameter of this method specifies
                // the XML that is used to generate the response.
                // The 4th parameter of this method includes the
                // request parameters, and they will be appear within
                // the CGI FORM as the default values.
                viewGenerator.writeResponseWithDefault(params,0,res,
                                 result.getResultMap(),values,true);
            }
        }
        catch(NestedException ex){
            throw ex;
        }
        catch(SimpleException ex){
            throw ex;
        }
        catch(Exception ex){
            throw (new NestedException(ex));
        }
    }

} //End of : CheckOnly