PC World 2001 March/PCWorld_2001-03_cd.bin/Software/Komercni/VAgeJava/ivj35/setup/JSP.Cab/F27261_LeapYear.java

Text File | 2000-08-10 | 6KB | 140 lines

package com.ibm.ivj.wte.samples.leapyear;

// Licensed Material - Property of IBM
// (C) Copyright IBM Corp. 2000 - All Rights Reserved
//
// DISCLAIMER:
// The following [enclosed] code is sample code created by IBM
// Corporation.  This sample code is not part of any standard IBM product
// and is provided to you solely for the purpose of assisting you in the
// development of your applications.  The code is provided 'AS IS',
// without warranty or condition of any kind.  IBM shall not be liable for any damages
// arising out of your use of the sample code, even if IBM has been
// advised of the possibility of such damages.

/**
 * Insert the type's description here.
 * Creation date: (05/22/2000 11:14:52 AM)
 * @author: Administrator
 */
public class LeapYear extends javax.servlet.http.HttpServlet {
private static final String copyright =
    "(c) Copyright IBM Corporation 2000.";

/**
 * Process incoming HTTP GET requests
 *
 * @param request Object that encapsulates the request to the servlet
 * @param response Object that encapsulates the response from the servlet
 */
public void doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, java.io.IOException {

    performTask(request, response);

}
/**
 * Process incoming HTTP POST requests
 *
 * @param request Object that encapsulates the request to the servlet
 * @param response Object that encapsulates the response from the servlet
 */
public void doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, java.io.IOException {

    performTask(request, response);

}
/**
 * Returns the requested parameter
 *
 * @param request Object that encapsulates the request to the servlet
 * @param parameterName The name of the parameter value to return
 * @param checkRequestParameters when true, the request parameters are searched
 * @param checkInitParameters when true, the servlet init parameters are searched
 * @param isParameterRequired when true, an exception is thrown when the parameter cannot be found
 * @param defaultValue The default value to return when the parameter is not found
 * @return The parameter value
 * @exception java.lang.Exception Thrown when the parameter is not found
 */
public String getParameter(javax.servlet.http.HttpServletRequest request, String parameterName, boolean checkRequestParameters, boolean checkInitParameters, boolean isParameterRequired, String defaultValue) throws Exception {

    String[] parameterValues = null;
    String paramValue = null;

    // Get the parameter from the request object if necessary.
    if (checkRequestParameters)
    {
      parameterValues = request.getParameterValues(parameterName);
      if (parameterValues != null)
           paramValue = parameterValues[0];
    }

    // Get the parameter from the servlet init parameters if
    // it was not in the request parameter.
    if ( (checkInitParameters) && (paramValue == null) )
      paramValue = getServletConfig().getInitParameter(parameterName);

    // Throw an exception if the parameter was not found and it was required.
    // The exception will be caught by error processing and can be
    // displayed in the error page.
    if ( (isParameterRequired) && (paramValue == null) )
         throw new Exception("Parameter " + parameterName + " was not specified.");

    // Set the return to the default value if the parameter was not found
    if (paramValue == null)
      paramValue = defaultValue;

    return paramValue;
}
/**
 * Process incoming requests for information
 *
 * @param request Object that encapsulates the request to the servlet
 * @param response Object that encapsulates the response from the servlet
 */
public void performTask(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws java.io.IOException {

    javax.servlet.ServletContext sc;
    javax.servlet.RequestDispatcher rd;

    try
    {
        com.ibm.ivj.wte.samples.leapyear.LeapYearBean leapYearBean = null;

        // instantiate the bean.
        leapYearBean = (com.ibm.ivj.wte.samples.leapyear.LeapYearBean) java.beans.Beans.instantiate(getClass().getClassLoader(),"com.ibm.ivj.wte.samples.leapyear.LeapYearBean");

        request.setAttribute("leapYearBean", leapYearBean);

        // Initialize the bean startYear property
        if (!getParameter(request, "startYear", true, true, true, null).equals("")) {
          leapYearBean.setStartYear(Integer.valueOf(getParameter(request, "startYear", true, true, true, null)).intValue());
        }

        // find next 10 leap years

        leapYearBean.findLeapYears();

        sc = getServletContext();
        rd = sc.getRequestDispatcher("/JSP/Sample3/LeapYearResults.jsp");       // for JSP 1.0
//        rd = sc.getRequestDispatcher("/JSP/Sample3/LeapYearResults091.jsp");       // for JSP 0.91
        rd.forward(request, response);

    }
    catch(Throwable theException)
    {
        // uncomment the following line when unexpected exceptions
        // are occuring to aid in debugging the problem.
        //theException.printStackTrace();
        response.setContentType("text/html");
        java.io.PrintWriter out =response.getWriter();
        out.println("<HTML>");
        out.println("<HEAD><TITLE>Find Next 10 Leap Years</TITLE></HEAD>");
        out.println("<BODY BGCOLOR=#C0C0C0>");
        out.println("<H2>Exception Occurred</H2>");
        out.println(theException);
        out.println("<P><I>Note: If the exception is java.lang.NumberFormatException, your input is probably not a number.<I>");
        out.println("</BODY></HTML>");
    }
}
}