Spring response entity image - spring

Question

I wrote a rest controller to return an image associated with a primary key. Now I wanted to load this image in the browser and I am running into issues:
(1) If I type a GET URL to the image the browser (FireFox and Chrome) don't display the image but they are seeing all the headers properly. Additionally firefox says "The image cannot be displayed because it contains errors"
(2) If I used XMLHttpRequest to create get the image using the URL I get the image but it displays only partially (the bottom half is cut off and is set to transparent).
#GetMapping("/{featureId}/loadImage")
public ResponseEntity<byte []> loadImageForId(#PathVariable long featureId, HttpServletResponse response) throws IOException {
log.info("Getting image for feature id " + featureId);
Feature feature = featureService.getFeatureById(featureId);
File file = featureService.loadImageForFeature(feature);
byte [] imageData = new byte[(int) file.length()];
FileInputStream inputStream = new FileInputStream(file);
inputStream.read(imageData);
inputStream.close();
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.parseMediaType(...));
headers.setContentLength(file.length());
response.setHeader("Content-Disposition", "inline; filename=" + file.getName());
return new ResponseEntity<byte[]>(imageData, headers, HttpStatus.OK);
}

Answer 1

if it is working on tomcat, you can use this tomcat's utility class :
import org.apache.tomcat.util.http.fileupload.IOUtils
for example:
response.setContentType("image/jpeg");
InputStream is = new ByteArrayInputStream(imageByteArray);
IOUtils.copy(is,response.getOutputStream());

Answer 2

Okay finally after hours of debugging with curl etc, I was able to verify that the response body was not getting properly encoded image (nothing to do with the headers).
This was caused due to the choice of InputStream and OutputStream objects.
Instead of using FileInputStream I switched to using ImageIO and the underlying BufferedImage to write the output to the ServletResponse as follows:
#GetMapping("/{featureId}/loadImage")
public void loadImageForId(#PathVariable long featureId, HttpServletResponse response) throws IOException {
log.info("Getting image for feature id " + featureId);
Feature feature = featureService.getFeatureById(featureId);
File imageFile = featureService.loadImageForFeature(feature);
MediaType mediaType = MediaType.parseMediaType(Files.probeContentType(imageFile.toPath()));
response.setHeader("Content-Disposition", "inline; filename=" + imageFile.getName());
response.setStatus(HttpStatus.OK.value());
response.setContentType(mediaType.toString());
response.setContentLength((int)imageFile.length());
OutputStream os = response.getOutputStream();
ImageIO.write(ImageIO.read(imageFile), mediaType.getSubtype(), os);
os.flush();
os.close();
}