OAF doesn't readily expose the Controller Servlet's HttpRequest and HttpResponse objects so you need to extract it from the OAPageContext object via:
HttpServletResponse response = (HttpServletResponse) pageContext.getRenderingContext().getServletResponse();
Once you get the response object you could already manipulate its OutputStream.
public void downloadFile(OAPageContext pageContext) {
HttpServletResponse response = (HttpServletResponse) pageContext.getRenderingContext().getServletResponse();
File fileToDownload = this.createFile();
String fileType = getMimeType("txt");
response.setContentType(fileType);
response.setContentLength((int) fileToDownload.length());
response.setHeader("Content-Disposition", "attachment; filename=\"" + fileToDownload.getName() + "\"");
InputStream in = null;
ServletOutputStream outs = null;
try {
outs = response.getOutputStream();
in = new BufferedInputStream(new FileInputStream(fileToDownload));
int ch;
while ((ch = in.read()) != -1) {
outs.write(ch);
}
} catch (IOException e) {
// TODO
e.printStackTrace();
} finally {
try {
outs.flush();
outs.close();
if (in != null) {
in.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}参考资料：
Integrate XML Publisher and OA Framework
Downloading Files in OAF (需翻墙)