QR Code encoding and decoding using zxing

Question

Okay, so I\'m going to take the off chance that someone here has used zxing before. I\'m developing a Java application, and one of the things it needs to do is encode a byte

Answer 1

I tried using ISO-8859-1 as said in the first answer. All went ok on encoding, but when I tried to get the byte[] using result string on decoding, all negative bytes became the character 63 (question mark). The following code does not work:

// Encoding works great
byte[] contents = new byte[]{-1};
QRCodeWriter codeWriter = new QRCodeWriter();
BitMatrix bitMatrix = codeWriter.encode(new String(contents, Charset.forName("ISO-8859-1")), BarcodeFormat.QR_CODE, w, h);

// Decodes like this fails
LuminanceSource ls = new BufferedImageLuminanceSource(encodedBufferedImage);
Result result = new QRCodeReader().decode(new BinaryBitmap( new HybridBinarizer(ls)));
byte[] resultBytes = result.getText().getBytes(Charset.forName("ISO-8859-1")); // a byte[] with byte 63 is given
return resultBytes;

It looks so strange because the API in a very old version (don't know exactly) had a method thar works well:

Vector byteSegments = result.getByteSegments();

So I tried to search why this method was removed and realized that there is a way to get ByteSegments, through metadata. So my decode method looks like:

// Decodes like this works perfectly
LuminanceSource ls = new BufferedImageLuminanceSource(encodedBufferedImage);
Result result = new QRCodeReader().decode(new BinaryBitmap( new HybridBinarizer(ls)));
Vector byteSegments = (Vector) result.getResultMetadata().get(ResultMetadataType.BYTE_SEGMENTS);  
int i = 0;
int tam = 0;
for (Object o : byteSegments) {
    byte[] bs = (byte[])o;
    tam += bs.length;
}
byte[] resultBytes = new byte[tam];
i = 0;
for (Object o : byteSegments) {
    byte[] bs = (byte[])o;
    for (byte b : bs) {
        resultBytes[i++] = b;
    }
}
return resultBytes;