try {
                Path path = Paths.get("ARQUIVO");
                byte[] data = Files.readAllBytes(path);

                HttpServletResponse httpServletResponse = response.raw();

                httpServletResponse.setContentType("application/pdf");
                httpServletResponse.addHeader("Content-Disposition", "inline; filename=mypdf.pdf");
                httpServletResponse.getOutputStream().write(data);
                httpServletResponse.getOutputStream().close();
            } catch (IOException e) {
                e.printStackTrace();
            }