Java Development Tools

Hi All

I am using Jdev 10.1.2 and I have some code in an app module method that I call from a button click on a struts page.

The code works everytime in debug mode but it only works once in run mode and then fails every other time i click the button.

Anyone know why this would happen. What run paramters are different in debug mode? Any help would be great

I have shortened the code

ByteArrayOutputStream baos = new ByteArrayOutputStream();
System.out.println("About to Write");
m_workbook.write(baos);
baos.flush();
baos.close();

Thanks