how check javabean giving to other component correct data

textbook example 12-3(david pasons java/xml) - DAO / DB-POOL / TOMCAT

At localhost
http://localhost:8080/jspadv/webhomecover/listclaims.jsp
I do NOT know, how debug? In debug a javabean, how check it is giving to other component CORRECT data?
The below means not find data ...? in db? may where clause faults?

org.apache.jasper.JasperException: javax.el.ELException: Error reading 'claims' on type com.webhomecover.beans.ClaimCollection
	org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:522)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:416)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

root cause

javax.el.ELException: Error reading 'claims' on type com.webhomecover.beans.ClaimCollection
	javax.el.BeanELResolver.getValue(BeanELResolver.java:66)
	javax.el.CompositeELResolver.getValue(CompositeELResolver.java:53)
	org.apache.el.parser.AstValue.getValue(AstValue.java:118)
	org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
	org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:925)
	org.apache.jsp.listclaims_jsp._jspx_meth_c_005fforEach_005f0(listclaims_jsp.java:125)
	org.apache.jsp.listclaims_jsp._jspService(listclaims_jsp.java:99)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

root cause

java.lang.NullPointerException
	com.webhomecover.dao.ClaimDAO.readClaims(Unknown Source)
	com.webhomecover.model.ModelFacade.getClaims(Unknown Source)
	com.webhomecover.beans.ClaimCollection.getClaims(Unknown Source)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	java.lang.reflect.Method.invoke(Method.java:597)
	javax.el.BeanELResolver.getValue(BeanELResolver.java:62)
	javax.el.CompositeELResolver.getValue(CompositeELResolver.java:53)
	org.apache.el.parser.AstValue.getValue(AstValue.java:118)
	org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
	org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:925)
	org.apache.jsp.listclaims_jsp._jspx_meth_c_005fforEach_005f0(listclaims_jsp.java:125)
	org.apache.jsp.listclaims_jsp._jspService(listclaims_jsp.java:99)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

<?xml version="1.0"?>

<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page"	
   xmlns:c="http://java.sun.com/jsp/jstl/core" 		
   version="2.0">
<jsp:directive.page isELIgnored="false" />
<jsp:directive.page contentType="text/html"/>   
<jsp:output omit-xml-declaration="false"
 doctype-root-element="html"
 doctype-public="-//W3C//DTD XHTML 1.1//EN" 
 doctype-system="http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd" />

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
 <link href="webhomecover.css" rel="stylesheet" type="text/css" />
 <title>Insurance Claims</title>
</head>
 <body>
  <p>Here is a list of claims</p>
  <table>
    <tr>
     <th>reference</th><th>description</th><th>amount</th><th>approved</th><th>claimDate</th>
    </tr>
 
    <jsp:useBean id="claimCollection" class="com.webhomecover.beans.ClaimCollection" />
    <c:forEach var="claim" items="${claimCollection.claims}">
     <tr>
      <td><c:out value="${claim.reference}" /></td>
      <td><c:out value="${claim.description}" /></td>
      <td><c:out value="${claim.amount}" /></td>
      <td><c:out value="${claim.approved}" /></td>
      <td><c:out value="${claim.claimDate}" /></td>
     </tr>
    </c:forEach>
   </table>
 </body>
 </html>
</jsp:root>

What is claimCollection.claims?

Is claims a list inside claimCollection?

Is it possible to have a look at how com.webhomecover.beans.ClaimCollection is made?

Last thing: you don't need to write line 26 if you use jstl.

claims is a list of claim.
String x=new String(); provides empty string or needed inside parenthesis "" (doublequotes)?

is it faults where clause?

//  com.webhomecover.dao.ClaimDAO.java
.....................
   public Collection<Claim> readClaims(String whereClause)
   {
    Collection<Claim> claims = new ArrayList<Claim>();
    try
    {
     getConnection();
     Statement statement = connection.createStatement();
     ResultSet results = statement.executeQuery("SELECT * FROM claim " + whereClause);
     String reference = null; 
     String description = null;
     double amount = 0.0;
     boolean approved = false;
     java.sql.Date claimDate = null;
     Claim claim = null;
     while(results.next())
     {
      reference = results.getString("reference"); 
 	  description = results.getString("description");
 	  amount = results.getDouble("amount");
 	  approved = results.getBoolean("approved");
 	  claimDate = results.getDate("claimDate");
 	  claim = new Claim();
 	  claim.setReference(reference);
 	  claim.setDescription(description);
 	  claim.setAmount(amount);
 	  claim.setApproved(approved);
 	  claim.setClaimDate(claimDate);
 	  claims.add(claim);
     }
     results.close();
     results = null;
     statement.close();
     statement = null;
     connection.close();
     connection = null;
    } 
    catch(SQLException e)
    {
     e.printStackTrace();
    }
    finally
    {
     cleanUp();
    }
    return claims;
   }  .....................

The constructor String() is ok.
Well, did you set in your servlet/action a request or session attribute with name claimCollection and with value a ClaimCollection object ?

in what file type, you mean?

Moving to our JSP forum.

Try this:

in your servlet set your collection as attribute to your request, with the following line.

and in your jsp you change the items on your forEach loop in this way:

Remember to delete line 26 in the jsp you posted.

I will test code tomorrow, but since, this is a textbook example inside the text, must be correct, any tip about this for the code(additional)?

It seems it's not, Leonidas, or you wouldn't have posted a question...
Check the solution i proposed to you, if you want, and see what happens.
If it won't work the problem is elsewhere, but we made a step further

you may find the complete app I refer at

http://www.cengage.co.uk/parsons/students/examples_exer.htm

Examples:Chapter 12: 12-3 folder [database in 12-1]

I am currently debugging...

import javax.naming.*;
in ClaimDAO.java needs include any in classbath ? during compile/run...