Get a BufferedImage from and OutputStream

Question

I have a function, int readFully(FileHandle handle, OutputStream out), which reads in an entire file from an SSH server and stores it in a local stream. I can write the file locally by using a FileOutputStream for the second parameter and then read that file into a BufferedImage using something like this:

bufferedImage = ImageIO.read(new File("/path/to/file"));

But how can I create the bufferedImage directly without first writing it to a file? I looked at this question, but still can't figure it out for my case.

Answer 1

Just write to a ByteArrayOutputStream instead - you can then create a ByteArrayInputStream to read from the same byte array, and then pass that to ImageIO.read(InputStream).

ByteArrayOutputStream output = new ByteArrayOutputStream();
readFully(handle, output);
byte[] data = output.toByteArray();
ByteArrayInputStream input = new ByteArrayInputStream(data);
BufferedImage image = ImageIO.read(input);

That's assuming you can't actually create an InputStream directly from the FileHandle, which would be even simpler.