loading a pdf in-browser from a file in the server file system? - spring

Question

How can I get a pdf located in a file in a server's directory structure to load in a browser for users of a Spring MVC application?
I have googled this and found postings about how to generate PDFs, but their answers do not work in this situation. For example, this other posting is not relevant because res.setContentType("application/pdf"); in my code below does not solve the problem. Also, this other posting describes how to do it from a database but does not show full working controller code. Other postings had similar problems that caused them not to work in this case.
I need to simply serve up a file (not from a database) and have it been viewable by a user in their browser. The best I have come up with is the code below, which asks the user to download the PDF or to view it in a separate application outside the browser. What specific changes can I make to the specific code below so that the user automatically sees the PDF content inside their browser when they click on the link instead of being prompted to download it?
#RequestMapping(value = "/test-pdf")
public void generatePdf(HttpServletRequest req,HttpServletResponse res){
res.setContentType("application/pdf");
res.setHeader("Content-Disposition", "attachment;filename=report.pdf");
ServletOutputStream outStream=null;
try {
BufferedInputStream bis = new BufferedInputStream(
new FileInputStream(new File("/path/to", "nameOfThe.pdf")));
/*ServletOutputStream*/ outStream = res.getOutputStream();
//to make it easier to change to 8 or 16 KBs
int FILE_CHUNK_SIZE = 1024 * 4;
byte[] chunk = new byte[FILE_CHUNK_SIZE];
int bytesRead = 0;
while ((bytesRead = bis.read(chunk)) != -1) {outStream.write(chunk, 0, bytesRead);}
bis.close();
outStream.flush();
outStream.close();
}
catch (Exception e) {e.printStackTrace();}
}

Answer 1

Change
res.setHeader("Content-Disposition", "attachment;filename=report.pdf");
To
res.setHeader("Content-Disposition", "inline;filename=report.pdf");
You should also set the Content Length
FileCopyUtils is handy:
#Controller
public class FileController {
#RequestMapping("/report")
void getFile(HttpServletResponse response) throws IOException {
String fileName = "report.pdf";
String path = "/path/to/" + fileName;
File file = new File(path);
FileInputStream inputStream = new FileInputStream(file);
response.setContentType("application/pdf");
response.setContentLength((int) file.length());
response.setHeader("Content-Disposition", "inline;filename=\"" + fileName + "\"");
FileCopyUtils.copy(inputStream, response.getOutputStream());
}
}