PrintWriter Solution to Flushing (seems like a hack tho)

Question

All,
I have been trying to write a XSS filter. The filtering was the easy part. For some reason, when I overload getWriter() in HttpServletResponseWrapper and return my own writer, the final buffer is not being flushed.
Here is what I have experienced. The following line of code was my first attempt:
return new PrintWriter(new XssPreventOutputStream(out));Nada. When I place debug statements in my output stream (which extends ServletOutputStream), the final buffer is never even passed to write(byte[], int, int). So, I extended PrintWriter and overloaded the following:
public void write(char[] buffer, int offset, int length) {
   super.write(buffer, offset, length);
   super.flush();  // Why do I have to do this?  This is what smells funny to me
}Placing an additional call to flush() in close() does nothing. I seem to have to flush() on every write(char[], int, int) in my overloaded PrintWriter. Am I doing something wrong? BTW, the custom output stream I wrote does nothing (yet):
public final void write(final byte[] buffer, final int offset, final int length)
          throws IOException {
          System.err.println("DEBUG >>> write(byte[] int, int) : \r\n" + new String(buffer, offset, length));
          out.write(buffer, offset, length);
     }I'm sure there is something so obviously simple it is completely escaping me right now. I just feel that issuing flush() after every write(char[], int, int) is a hack.
Thanks!
- Saish

Answer 1

Thanks for the replies. If I overload close() and place debugging statements in there, it is being called. I am overloading the PrintWriter returned by ServletResponse#getPrintWriter(). So, I do not really have explicit control (nor do I think I should) when Struts is being used.
Another oddity, not sure if it will help, but I do see debugging messages that flush() is also being called, to no effect unless I place the flush in write(char[], int, int), which to me seems like a mistake. (Sorry if this is too vague).
- Saish