title: struts 2 Can not find a java.io.InputStream with the name [excelStream] in the invocation stack
body: <p>excelStreamI am trying to download an excel file.</p>
  
  <p>In my Action class</p>
  
  <pre><code>public class ActivityTrackerExlReportAction extends BaseAction 
  {
  private  InputStream excelStream;
  private UserMasterDTO userMasterDTO;
  
  public InputStream getExcelStream() 
  {
   return excelStream;
  }
  
  public void setExcelStream(InputStream excelStream) {
  this.excelStream = excelStream;
  }
  
  ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
  WorkbookSettings wbSettings = new WorkbookSettings();
  
  try
  {
    response.setHeader("Content-Disposition", "attachment; filename=/timesheet.xls");
    wbSettings.setLocale(new Locale("en", "EN"));
    WritableWorkbook workbook = Workbook.createWorkbook(outputStream, wbSettings);
    workbook.createSheet("Report", 0);
    WritableSheet excelSheet = workbook.getSheet(0);
    service.createLabel(excelSheet);
    service.createContent(excelSheet);  
  
    workbook.write();
  
    ByteArrayInputStream inputStream = new ByteArrayInputStream(outputStream.toByteArray());
  
    setExcelStream(inputStream);
  
    workbook.close();
  
    outStream.flush();
  
    outStream.close();
  }
  catch(Exception e)
  {
  }
  finally
  {
  // outStream.close();
   }
   return "generateReport
  }
  </code></pre>
  
  <p>My <code>struts.xml</code> contains:</p>
  
  <pre><code>&lt;result type="stream" name="generateReport"&gt;
   &lt;param name="contentType"&gt;"application/vnd.ms-excel"&lt;/param&gt;
   &lt;param name="inputName"&gt;excelStream&lt;/param&gt;
   &lt;param name="bufferSize"&gt;1024&lt;/param&gt;
  &lt;/result&gt;
  </code></pre>
  
  <p>I am using <code>JXL</code> to create and write an Excel sheet. Why am i getting the error and how to get out of it? Can not find a <code>java.io.InputStream</code> with the name <code>[excelStream]</code> in the invocation stack</p>
  
  <p>My are Stacktraces:</p>
  
  <blockquote>
    <p>java.lang.IllegalArgumentException: Can not find a java.io.InputStream with the name [excelStream] in the invocation stack. Check the tag specified for this action.</p>
    
    <p>org.apache.struts2.dispatcher.StreamResult.doExecute(StreamResult.java:237)</p>
    
    <p>org.apache.struts2.dispatcher.StrutsResultSupport.execute(StrutsResultSupport.java:186)
    .......</p>
  </blockquote>