JSTL and accessing Beans

Erikxxx · Nov 10, 2005

Hi all,

I'm having the following problem when I'm trying to access an array from a bean using JSTL. Can anyone explain for me why this doesn't work. The error Tomcat(5) using JSTL1.0 output is

Unable to find a value for "myList" in object of class "PhoneList" using operator "." (null)

These are the files I'm using

File:tester.jsp
<%@ taglib uri="

http://java.sun.com/jstl/core"

prefix="c" %>
<jsp:useBean id="list" class="PhoneList" scope="request"/>

<c:forEach items="${list.myList}" var="entry">
<c

ut value="${entry}";
></c:forEach>

import java.util.*;
public class PhoneList {
ArrayList myList;
public PhoneList()
{
myList = new arrayList();
myList.add("name1");
myList.add("name2");
}

public void setMyList(ArrayList l)
{ myList = l; }

public ArrayList getMyList()
{ return myList;}
}

Thanks
Erik

Diancecht · Nov 10, 2005

Doesn't a bean need an empty constructor?

Cheers,
Dian

icecuber · Nov 10, 2005

I have a similar problem... i'm a tag lib newbie and i have to understand how pass object from scriptlet <% .. %> world to tablig....

i feel tha tag lib are very clean.. but they are only for bean!?!?!? how can i iterate over a list or even a simply plain array of string object?
i have to exlicit put in context like this?

Code:

pageContext.setAttribute("objectNameForTagLib",objectName);

i also try to instantiate with bean syntax

Code:

<jsp:useBean id="beanName" scope="page"  class="beanClass" />

but it's strictly for bean.. i'd like to instantiate ArrayList, maps Generics and so on... is it possible without scriptlet?
i read that with taglib we have a scriptless jsp... but at this time i don't have a clue on how to do a lot of things with taglibs

p.s. i look on google result, on sun's page but i don't find a clear and comprensive taglib tutorial for beginner (or dummies) do you know some!?!?

Thanks in advice

Diancecht · Nov 10, 2005

Forget my first post.

What about making the list public?

Cheers,
Dian

venur · Nov 10, 2005

Hi,

Below is the example hope this will help you start with JSTL and JavaBean. Make sure that the JavaBean is in the package.

Java Bean

Code:

package com.test.bean;
import java.util.ArrayList;

public class TestBean 
{
  private ArrayList list = null;

  public TestBean()
  {
    list = new ArrayList();
    list.add("one");
    list.add("two");
    list.add("three");
  }

  public void setList(ArrayList list)
  {
    this.list = list;
  }

  public ArrayList getList()
  {
    return list;
  }
   
}

JSP code

Code:

<%@ taglib uri="[URL unfurl="true"]http://java.sun.com/jstl/core"[/URL] prefix="c"%>
<%@ page contentType="text/html;charset=windows-1252"%>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
    <title>JSTL Test</title>
  </head>
  <body>
  This is a simple test for bean using useBean and iterate over the list using JSTL 
  <br>
  <jsp:useBean id="myList" class="com.test.bean.TestBean" scope="page"/>
  
  <c:forEach items="${myList.list}" var="itemValue" varStatus="idx">
   <c:out value="${idx.index}"/>
   &nbsp;&nbsp;&nbsp;
   <c:out value="${itemValue}"/>
   <br>
  </c:forEach>
  </body>
</html>

Hope this will help you.

Cheers
Venu

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JSTL and accessing Beans

Erikxxx

Programmer

Diancecht

Programmer

icecuber

Programmer

Diancecht

Programmer

venur

MIS

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