Problem with Export to Excel Feature in Oracle 12c

I am trying export the table data to excel sheet using Export to Excel in 12c,it is giving the errors like <org.apache.myfaces.trinidad.component.UIXCollection> <UIXCollection> <_verifyComponentInContext> <COLLECTION_NOT_IN_CONTEXT>.

To make it work we can alternatively use the download listener(af:fileDownloadActionListener) and apache POI.

Follow the below process.

1. Download the Apache POI jar and add it to project libraries.
2. Create a page and drag and drop the view object as a table
3. Drag and drop the button on the page and add a fileDownloadListener(af:fileDownloadActionListener) to the button
4. Point the method attribute of the file download listener to a managed bean method.

//This is the code you will have in the page

<af:fileDownloadActionListener contentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"

                                   filename="EmployeeDtails" method="#{pageFlowScope.EmployesBean.downLoadExcel}"/> 

5. Write the below code in the method that creates and downloads the excel file.

//This is the managed bean method

        public void downLoadExcel(FacesContext facesContext, OutputStream outputStream) {

                        try {

                                   HSSFWorkbook workbook = new HSSFWorkbook();

                                   HSSFSheet worksheet = null;

                               worksheet = workbook.createSheet("Employee Details");

                       DCBindingContainer bindings = (DCBindingContainer) BindingContext.getCurrent().getCurrentBindingsEntry();

                                   DCIteratorBinding dcIteratorBindings = bindings.findIteratorBinding(iterName);

                       RowSetIterator rowSetIterator=  dcIteratorBindings.getRowSetIterator();

                       rowSetIterator=  dcIteratorBindings.getViewObject().createRowSetIterator("ExportToExcel");

                                   int i = 0;

                                   Row row=null;

                                    HSSFRow excelrow = null;

                                   while(rowSetIterator.hasNext()){

                                        row=rowSetIterator.next();

                                       if (i == 0) {

                                           excelrow = (HSSFRow) worksheet.createRow(i);

                                       int j = 0;                      

                                           for (String colName : row.getAttributeNames()) {                      

                                               HSSFCell cellA1 = excelrow.createCell(j);

                                                        cellA1.setCellValue(colName);

                                                       }

                                                    j++;

                                                  }

                                                   }

                      

                                       ++i;

                                       int j = 0;

                                       excelrow = worksheet.createRow(i);

                                       for (String colName : row.getAttributeNames()) {

                                                   HSSFCell cell = excelrow.createCell(j);

                                                   cell.setCellValue(row.getAttribute(colName).toString());

                                                   }  

                                               j++;

                                               workbook.write(outputStream);

                                               outputStream.flush();

                                               outputStream.close();

                                               rowSetIterator.closeRowSetIterator();

                                               logger.info("Export excel is finished");

                                               } catch (IOException e) {

                                               e.printStackTrace();

                                               }

                                           }

Reference 

http://www.techartifact.com/blogs/2013/08/generate-excel-file-in-oracle-adf-using-apache-poi.html#sthash.XzGOCOMf.dpbs