//get the file name from the 'file' parameter
String fileName = (String) request.getParameter("file");
if (fileName == null || fileName.equals(""))
throw new ServletException(
"Invalid or non-existent file parameter in UrlServlet servlet.");
// add the .pdf suffix if it doesn't already exist
if (fileName.indexOf(".pdf") == -1)
fileName = fileName + ".pdf";
URL pdfDir = null;
URLConnection urlConn = null;
ServletOutputStream stream = null;
BufferedInputStream buf = null;
try{
//where are PDFs kept? remote-pdf-dir=http://www.jspservletcookbook.com/downloads/
pdfDir = new URL(getServletContext().getInitParameter("remote-pdf-dir") + fileName);
} catch (MalformedURLException mue){
throw new ServletException(mue.getMessage());
}
try{
stream = response.getOutputStream();
//set response headers
response.setContentType("application/pdf");
response.addHeader(
"Content-Disposition","attachment; filename="+fileName );
urlConn = pdfDir.openConnection();
response.setContentLength( (int) urlConn.getContentLength() );
buf = new BufferedInputStream(urlConn.getInputStream());
int readBytes = 0;
//read from the file; write to the ServletOutputStream
while((readBytes = buf.read()) != -1)
stream.write(readBytes);
} catch (IOException ioe){
throw new ServletException(ioe.getMessage());
} finally {
//close the input/output streams
if(stream != null)
stream.close();
if(buf != null)
buf.close();
}
