leapyear.java

EJB最新技术开发指南源代码

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>");
	}
}
}