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

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?

Donielle

Store the image as base64 encoded string and return that string. I can provide a sample code if needed – Eldwun

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();
    }
}

Douville

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();
}

Ricardo

Hi, You are returning inputstream in this method is returning byte[] array. It is giving error. and should I have to add something in pom.xml or any file? – Donielle

You were right i told you i dont have the enviroment in this machine, however i have updated the answer please check – Ricardo

even better if you directly returned os.toByteArray() – Electrokinetic

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?

Vostok