convert image to base64 with java

Question

I need to convert a image object to a base64 object so I can load it into the tag on my client side.

However I can't seem to figure out how to pull this off. Is there anyone who has a piece of code for this that I could use easily?

This is what I use to turn the external image link into a image object

Image image = null;
URL url = new URL(request.getParameter("hdn_path"));
image = ImageIO.read(url);

not sure if I'm going about this the correct way.

Answer 1

Using Apache IOUtils and Base64:

byte[] imageBytes = IOUtils.toByteArray(new URL("...")));
String base64 = Base64.getEncoder().encodeToString(imageBytes);

Answer 2

• write using ImageIO.write().
• ByteArrayOutputStream wraps the byte array so it can be used as an output stream.
• convert the byte array to a a base64 string using DatatypeConverter, in core Java since 6, no extra libraries required

Example

ByteArrayOutputStream output = new ByteArrayOutputStream();
ImageIO.write(image, "png", output);
DatatypeConverter.printBase64Binary(output.toByteArray());