// Copyright 2002 Nokia Corporation.//// THIS SOURCE CODE IS PROVIDED 'AS IS', WITH NO WARRANTIES WHATSOEVER,// EXPRESS OR IMPLIED, INCLUDING ANY WARRANTY OF MERCHANTABILITY, FITNESS// FOR ANY PARTICULAR PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE// OR TRADE PRACTICE, RELATING TO THE SOURCE CODE OR ANY WARRANTY OTHERWISE// ARISING OUT OF ANY PROPOSAL, SPECIFICATION, OR SAMPLE AND WITH NO// OBLIGATION OF NOKIA TO PROVIDE THE LICENSEE WITH ANY MAINTENANCE OR// SUPPORT. FURTHERMORE, NOKIA MAKES NO WARRANTY THAT EXERCISE OF THE// RIGHTS GRANTED HEREUNDER DOES NOT INFRINGE OR MAY NOT CAUSE INFRINGEMENT// OF ANY PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OWNED OR CONTROLLED// BY THIRD PARTIES//// Furthermore, information provided in this source code is preliminary,// and may be changed substantially prior to final release. Nokia Corporation// retains the right to make changes to this source code at// any time, without notice. This source code is provided for informational// purposes only.//// Nokia and Nokia Connecting People are registered trademarks of Nokia// Corporation.// Java and all Java-based marks are trademarks or registered trademarks of// Sun Microsystems, Inc.// Other product and company names mentioned herein may be trademarks or// trade names of their respective owners.//// A non-exclusive, non-transferable, worldwide, limited license is hereby// granted to the Licensee to download, print, reproduce and modify the// source code. The licensee has the right to market, sell, distribute and// make available the source code in original or modified form only when// incorporated into the programs developed by the Licensee. No other// license, express or implied, by estoppel or otherwise, to any other// intellectual property rights is granted herein.package example.sum;import java.util.Enumeration;import java.io.*;import javax.servlet.*;import javax.servlet.http.*;public class SumServlet    extends HttpServlet{    public void init(ServletConfig config) throws ServletException    {        super.init(config);    }    public void doPost(HttpServletRequest  request,                       HttpServletResponse response)        throws IOException, ServletException    {        try        {            // First handle session            HttpSession session = request.getSession(false);            if (session == null)  // first connection?            {                session = request.getSession(true);   // create                String requestUrl = request.getRequestURL().toString();                String rewrittenUrl = response.encodeURL(requestUrl);                response.setHeader("X-RewrittenURL", rewrittenUrl);            }            // read request            InputStream in = request.getInputStream();            int requestLength = request.getContentLength();            if (requestLength == -1)            {                throw new IOException("Need to know request length");            }            StringBuffer buf = new StringBuffer(requestLength);            for (int i = 0; i < requestLength; ++i)            {                int ch = in.read();                if (ch == -1)                {                    break;                }                buf.append((char)ch);            }            in.close();            String requestStr = buf.toString();            // process request, producing response            String responseStr;            int totalSoFar = 0;            Integer savedTotal = (Integer)(session.getAttribute("total"));            if (savedTotal != null)            {                totalSoFar = savedTotal.intValue();            }            try            {                int newValue = Integer.parseInt(requestStr);                totalSoFar += newValue;                responseStr = Integer.toString(totalSoFar);            }            catch (NumberFormatException e)            {                responseStr = "Error";            }            session.setAttribute("total", new Integer(totalSoFar));            // write response            response.setContentType("text/plain");            PrintWriter out = response.getWriter();            out.write(responseStr);            out.close();        }        catch (IOException e)        {            e.printStackTrace();            throw e;        }        catch (Exception e)        {            e.printStackTrace();            throw new ServletException(e.getMessage());        }    }    public String getServletInfo()    {        return "Sum Servlet.";    }}