Генерация QR-кода программно

ZXing and QRGen.

public class CreateQrCode {
public static void main(String... args){
    ByteArrayOutputStream bout =
            QRCode.from("your text")
                    .withSize(250, 250)
                    .to(ImageType.PNG)
                    .stream();
    try {
        OutputStream out = new FileOutputStream("qr-code.png");
        bout.writeTo(out);
        out.flush();
        out.close();
    } catch (FileNotFoundException e){
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
 }
}

Примеры кода