How to Suppress Extension Warning in Excel


I have created an Excel file from my JTable. The same button that creates it also opens it. But it gives a prompt :


The file you are trying to open is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a trusted user before opening the file. Do you want to open the file?


When I click OK the file opens. I am using Office 2007 and am saving the file as .xls. Is there a way of stopping the prompt from the code level? Here is the code that creates and opens the file:

if (obj == btnExport) { File f = new File("Student Results"); f.mkdir(); try { TableModel model = DataBaseTable.getModel(); FileWriter excel = new FileWriter("Student Results/" + exam + "_"+ level + "_" + year + ".xls"); for(int i = 0; i < model.getColumnCount(); i++){ excel.write(model.getColumnName(i) + "\t"); } excel.write("\n"); for(int i=0; i< model.getRowCount(); i++) { for(int j=0; j < model.getColumnCount(); j++) { excel.write(model.getValueAt(i,j).toString()+"\t"); } excel.write("\n"); } excel.close(); JOptionPane.showMessageDialog(this, "File Exported to " + f.getAbsolutePath(), "Success", JOptionPane.INFORMATION_MESSAGE); File opn = new File("Student Results/" + exam + "_"+ level + "_" + year + ".xls"); Desktop.getDesktop().open(opn); } catch (Exception se) { JOptionPane.showMessageDialog(this, se, "Error", JOptionPane.ERROR_MESSAGE); } }


<a href="http://support.microsoft.com/kb/948615" rel="nofollow">This MSDN</a> gives a couple methods (group policy, or registry manipulation) for how you could suppress the warning, but I don't think either are particularly practical.

I would recommend making a CSV instead, since you are just writing a file. Those are also opened by Excel. I believe all you'd have to do is subsituted a comma for both of your \ts in your code.


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