Java Image Encoding Detection

Question

I accept the image as input from the user. I want to allow only JPEG image. The image comes as an InputStream (called myInputStreambelow). In the code below, the Iterator returned ImageIO.getImageReaders()is always empty.

ImageInputStream imageInputStream = ImageIO.createImageInputStream(
    myInputStream);
Iterator<ImageReader> iter = ImageIO.getImageReaders(imageInputStream);
if (!iter.hasNext()) {
    // this always happens
}
ImageReader reader = (ImageReader) iter.next();
if (!reader.getFormatName().equals("jpeg")) {
    // haven't got this far yet
}

I also tried passing myInputStreamdirectly on ImageIO.getImageReaders()with the same result.

Answer 1

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