i've tried one of the sample inside the pdf help on javabean that u've posted. but there is still some minor error. could you help me on it? thanks
the codes for java page is
package coreServlets;
public class SaleEntry {
private String itemID = "unknow";
private double discountCode = 2.0;
private int numItems = 0;
public String getItemID(){
return (itemID);
}
public void setItemID(String itemID){
if(itemID != null) {
this.itemID = itemID;
}
else {
this.itemID = "unknow";
}
}
public double getDiscountCode(){
return (discountCode);
}
public void setDiscountCode(double discountCode){
this.discountCode = discountCode;
}
public int getNumItems(){
return (numItems);
}
public void setNumItems(int numItems){
this.numItems = numItems;
}
public double getItemCost(){
double cost;
if(itemID.equals("a1234")){
cost = 12.99 * getDiscountCode();
}else{
cost = -9999;
}
return roundToPremises(cost);
}
private double roundToPremises(double cost){
return (Math.floor(cost *100/100.0));
}
public double getTotalCost(){
return (getItemCost() * getNumItems());
}
}
the code of jsp page are
<html>
<head><title>Using jsp</title></head>
<body>
<table border=1 align="center">
<tr>
<th class="title">Using jsp: setProperty</th></table>
<jsp:useBean id="entry" class="coreServlets.SaleEntry" />
<jsp:setProperty name="entry" property="itemID" value='<%= request.getParameter("itemID") %>'/>
<%
int numItemsOrdered = 1;
try{
numItemsOrdered = Integer.parseInt(request.getParameter("numItems"));
}catch(NumberFormatException nfe){}
%>
<jsp:setProperty name="entry" property="numItems" value="<%= numItemsOrdered %>" />
<%
double discountCode = 2.0;
try{
String discountString = request.getParameter("discountCode");
discountCode = Double.valueOf(discountString).doubleValue();
}catch(NumberFormatException nfe){}
%>
<jsp:setProperty name="entry" property="discountCode" value="<%= discountCode %>" />
<br>
<table align="center" border=1>
<tr class="colored">
<th>Item ID<th>Unit Price<th>Number Ordered<th>Total Price
<tr align="right">
<td><jsp:getProperty name="entry" property="itemID" />
<td><jsp:getProperty name="entry" property="itemCost" />
<td><jsp:getProperty name="entry" property="numItems" />
<td><jsp:getProperty name="entry" property="totalCost" />
</table>
</body>
</html>
the error message that the eclipse showed me is
HTTP Status 500 -
--------------------------------------------------------------------------------
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: Exception in JSP: /SaleEntry.jsp:26
23: double discountCode = 2.0;
24: try{
25: String discountString = request.getParameter("discountCode");
26: discountCode = Double.valueOf(discountString).doubleValue();
27: }catch(NumberFormatException nfe){}
28:
29: %>
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:504)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause
java.lang.NullPointerException
sun.misc.FloatingDecimal.readJavaFormatString(Unknown Source)
java.lang.Double.valueOf(Unknown Source)
org.apache.jsp.SaleEntry_jsp._jspService(SaleEntry_jsp.java:81)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:332)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.17 logs.
--------------------------------------------------------------------------------
Apache Tomcat/5.5.17
hope that you could help on it. thanks