[FIXED] How to convert S3ObjectInputStream to Base64 url?

Issue

I have a png image file in an AWS S3 bucket. I'm trying to get this image using Java SDK. So far, here is what I have done:

public String encodeBase64URL(BufferedImage imgBuf) throws IOException {
    String base64;

    if (imgBuf == null) {
        base64 = null;
    } else {
        Base64 encoder = new Base64();
        ByteArrayOutputStream out = new ByteArrayOutputStream();

        ImageIO.write(imgBuf, "PNG", out);

        byte[] bytes = out.toByteArray();
        base64 = "data:image/png;base64," + encoder.encode(bytes)
                .toString();
    }

    return base64;
}

public String saveImageToS3(BufferedImage imgBuf, String id) throws IOException {
    AmazonS3 s3 = new AmazonS3Client();

    File file = File.createTempFile(id, ".png");
    file.deleteOnExit();

    ImageIO.write(imgBuf, "png", file);

    s3.putObject(new PutObjectRequest(bucketName, id, file));
    file.delete();

    return bucketName;
}

public String downloadImageFromS3(String id) throws IOException {
    AmazonS3 s3 = new AmazonS3Client();

    S3Object obj = s3.getObject(new GetObjectRequest(bucketName, id));
    BufferedImage imgBuf = ImageIO.read(obj.getObjectContent());

    String base64 = encodeBase64URL(imgBuf);
    return base64;
}

The saveImageToS3 method works exactly as expected. However, the second method returns data:image/png;base64,[B@428d24fa while it should have been a valid Base64.

What am I doing wrong? Please help.

Solution

Instead of calling toString() on the resulting byte[] which will result in the very unhelpful [B@428d24fa format, you need to create a new String using the returned bytes:

base64 = "data:image/png;base64," + new String(encoder.encode(bytes), "UTF-8");

Answered By - Kayaman
Answer Checked By - Katrina (JavaFixing Volunteer)