java - Write Base64-encoded image to file

Question

How to write a Base64-encoded image to file?

I have encoded an image to a string using Base64. First, I read the file, then convert it to a byte array and then apply Base64 encoding to convert the image to a string.

Now my problem is how to decode it.

byte dearr[] = Base64.decodeBase64(crntImage);
File outF = new File("c:/decode/abc.bmp");
BufferedImage img02 = ImageIO.write(img02, "bmp", outF); 

The variable crntImage contains the string representation of the image.

Answer 1

Assuming the image data is already in the format you want, you don't need image ImageIO at all - you just need to write the data to the file:

// Note preferred way of declaring an array variable
byte[] data = Base64.decodeBase64(crntImage);
try (OutputStream stream = new FileOutputStream("c:/decode/abc.bmp")) {
    stream.write(data);
}

(I'm assuming you're using Java 7 here - if not, you'll need to write a manual try/finally statement to close the stream.)

If the image data isn't in the format you want, you'll need to give more details.