How to return an Image to browser in rest API in JAVA? - spring

Question

I want to an image while I hit an API like localhost:8080:/getImage/app/path={imagePath}
While I hit this API it will return me an Image.
Is this possible?
Actually, I have tried this but it is giving me an ERROR.
Here is my code,
#GET
#Path("/app")
public BufferedImage getFullImage(#Context UriInfo info) throws MalformedURLException, IOException {
String objectKey = info.getQueryParameters().getFirst("path");
return resizeImage(300, 300, objectKey);
}
public static BufferedImage resizeImage(int width, int height, String imagePath)
throws MalformedURLException, IOException {
BufferedImage bufferedImage = ImageIO.read(new URL(imagePath));
final Graphics2D graphics2D = bufferedImage.createGraphics();
graphics2D.setComposite(AlphaComposite.Src);
// below three lines are for RenderingHints for better image quality at cost of
// higher processing time
graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
graphics2D.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
graphics2D.drawImage(bufferedImage, 0, 0, width, height, null);
graphics2D.dispose();
System.out.println(bufferedImage.getWidth());
return bufferedImage;
}
My ERROR,
java.io.IOException: The image-based media type image/webp is not supported for writing
Is there any way to return an Image while hitting any URL in java?

Answer 1

You can use IOUtils. Here is code sample.
#RequestMapping(path = "/getImage/app/path/{filePath}", method = RequestMethod.GET)
public void getImage(HttpServletResponse response, #PathVariable String filePath) throws IOException {
File file = new File(filePath);
if(file.exists()) {
String contentType = "application/octet-stream";
response.setContentType(contentType);
OutputStream out = response.getOutputStream();
FileInputStream in = new FileInputStream(file);
// copy from in to out
IOUtils.copy(in, out);
out.close();
in.close();
}else {
throw new FileNotFoundException();
}
}

Answer 2

i didn't test it due to i don't have the environment in this machine, but logically it should work like the following, read it as input stream and let your method returns #ResponseBody byte[]
#GET
#Path("/app")
public #ResponseBody byte[] getFullImage(#Context UriInfo info) throws MalformedURLException, IOException {
String objectKey = info.getQueryParameters().getFirst("path");
BufferedImage image = resizeImage(300, 300, objectKey);
ByteArrayOutputStream os = new ByteArrayOutputStream();
ImageIO.write(image, "jpg", os);
InputStream is = new ByteArrayInputStream(os.toByteArray());
return IOUtils.toByteArray(is);
}
UPDATE
depending on #Habooltak Ana suggestion there is no need to create an input stream, the code should be look like the following
#GET
#Path("/app")
public #ResponseBody byte[] getFullImage(#Context UriInfo info) throws
MalformedURLException, IOException {
String objectKey = info.getQueryParameters().getFirst("path");
BufferedImage image = resizeImage(300, 300, objectKey);
ByteArrayOutputStream os = new ByteArrayOutputStream();
ImageIO.write(image, "jpg", os);
return os.toByteArray();
}

Answer 3

Just return a file object with correct HTTP-Headers (Content-Type and Content-Disposition) will work in most cases/environments.
Pseudocode
File result = createSomeJPEG();
/*
e.g.
RenderedImage rendImage = bufferedImage;
File file = new File("filename.jpg");
ImageIO.write(rendImage, "jpg", file);
*/
response().setHeader("Content-Disposition", "attachment;filename=filename.jpg;");
response().setHeader("Content-Type", "image/jpeg");
return ok(result);
See also:
file downloading in restful web services
what's the correct way to send a file from REST web service to client?