file upload : Could not load class UploadPage from ContextLoader

[Dwi Ardi Irawan]

i'm a newbie
i have tried upload in the tapestry Tapestry Component Reference.
but i've got some error :

      org.apache.tapestry.ApplicationRuntimeException 
      Could not load class UploadPage from [EMAIL 
PROTECTED](file:/C:/my%20workspace/eols/webapp/WEB-INF/classes/) --parent--> 
[EMAIL PROTECTED]: UploadPage

      could anyone help me ?
      this is the code :

      Documents.java
      
===============================================================================================
 

package edu.eols.web.page;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.text.Format;
import java.text.NumberFormat;

import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.html.BasePage;
import org.apache.tapestry.request.IUploadFile;

public class Documents extends BasePage {
 public static final Format SIZE_FORMAT = NumberFormat.getNumberInstance();    
    private IUploadFile file;
    private File serverFile;

    public IUploadFile getFile() { return file; }

    public void setFile(IUploadFile value) {
        file = value;
    }

    public String getFilename() { 
        if (file != null) {
            return file.getFileName();
        } else {
            return "";   
        }        
    }

    public String getClientPath() { 
        if (file != null) { 
            return file.getFilePath(); 
        } else {
            return ""; 
        } 
    } 
    
    public String getServerPath() { 
        if (serverFile != null) { 
            return serverFile.getAbsolutePath(); 
        } else { 
            return "";  
        }
    }

    public long getFileSize() { 
        if (serverFile != null) {
            return serverFile.length();
        } else {
            return 0;   
        }        
    } 

    public void formSubmit(IRequestCycle cycle) { 
        InputStream fis = file.getStream(); 
        FileOutputStream fos = null;
         
        try { 
            fos = new FileOutputStream(new  File(file.getFileName()));
            byte[] buffer = new byte[1024];  
            while (true) {            
                int length = fis.read(buffer);  
                if (length <  0) {
                    break;
                }
                fos.write(buffer, 0, length);               
            }
            fis.close();
            fos.close();
            serverFile = new File(file.getFileName());

        } catch (IOException ioe) {
            ioe.printStackTrace();            
        } finally {
            if (fis != null) {
                try { fis.close(); } catch (IOException ioe) {}
            }   
            if (fos != null) {
                try { fos.close(); } catch (IOException ioe) {}
            }
        }
    }

    protected void initialize() {
        file = null;
        serverFile = null;
    }

}

============================================================================
Documents.html
<form jwcid="@Form" listener="ognl:listeners.formSubmit"> 

<table width="100%" border="0">

<tr>

<td colspan="2">File:&nbsp;<input jwcid="@Upload" file="ognl:file" type= 
"file"></input></td>

</tr>

<tr>

<td colspan="2"><input type= "submit"value="Upload"></input></td>

</tr>

<tr>

<td colspan="2"><hr></td>

</tr>

<tr>

<td>Filename:</td><td><span jwcid="@Insert" value="ognl:filename"/></td>

</tr>

<tr>

<td>Client path:</td><td><span jwcid="@Insert" value="ognl:clientPath"/></td>

</tr>

<tr>

<td>Server Path:</td><td><span jwcid="@Insert" value="ognl:serverPath"/></td>

</tr>

<tr>

<td>File Size:</td><td><span jwcid="@Insert" value="ognl:fileSize" 
format="ognl:@[EMAIL PROTECTED]"/>&nbsp;bytes</td>

</tr>

</table>

</form> 



================================================================

Documents.page

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE page-specification PUBLIC
  "-//Apache Software Foundation//Tapestry Specification 3.0//EN"
  "http://jakarta.apache.org/tapestry/dtd/Tapestry_3_0.dtd";>
<!-- generated by Spindle, http://spindle.sourceforge.net -->

<page-specification class="edu.eols.web.page.Documents">

    <description>add a description</description>
    <context-asset name="home_01" path="/images/home_01.gif"/>
    <context-asset name="home_02" path="/images/home_02.gif"/>
    <context-asset name="home_03" path="/images/home_03.gif"/>
    <context-asset name="home_04" path="/images/home_04.gif"/>
    <context-asset name="home_05" path="/images/home_05.gif"/>
    <context-asset name="home_06" path="/images/home_06.gif"/>
    <context-asset name="home_07" path="/images/home_07.gif"/>

    
    
</page-specification>




====================================================================

eosl.application

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE application PUBLIC
  "-//Apache Software Foundation//Tapestry Specification 3.0//EN"
  "http://jakarta.apache.org/tapestry/dtd/Tapestry_3_0.dtd";>
<!-- generated by Spindle, http://spindle.sourceforge.net -->

<application name="eols" engine-class="org.apache.tapestry.engine.BaseEngine">
    
    <description>add a description</description>    
    <page name="Home" specification-path="Documents.page"/>  
    <extension name="org.apache.tapestry.multipart-decoder" 
class="org.apache.tapestry.multipart.DefaultMultipartDecoder">
       <configure property-name="maxSize" type="double" value="134217728"/>
    </extension>
        
    
</application>