I'm using JDBC to fetch data from database and then I use iText to create a PDF file which can be downloaded on client machine. The application is coded in HTML/JSP and runs on Apache Tomcat.
I use the
response.getOutputStream to create an output PDF file immediately. However, I get the following error:
getOutputStream() has already been called for this response
How can I generate a dynamic PDF file which can be downloaded by client machine?
When you write JSP, you probably like white space and indentation.
This will always cause the exception
"getOutputStream() has already been called for this response" regardless if you're using iText or not. The
getOutputStream() method was called the moment you introduced your first white space character in your JSP script.
To fix this, you need to remove all white space.
Not a single character is accepted outside the code and markers. As explained in the better JSP manuals, you shouldn't use JSP to create binary files. Why not? Because JSP introduces white space characters at arbitrary places in your binary file. That results in corrupt files. Use Servlets instead!