How to extract the totp secret from a QR code

QrCodeExtractor.java

package scratch;

import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;

import javax.imageio.ImageIO;

import com.google.zxing.BinaryBitmap;
import com.google.zxing.ChecksumException;
import com.google.zxing.FormatException;
import com.google.zxing.NotFoundException;
import com.google.zxing.Result;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.QRCodeReader;

/**
 * Needs:
 * <pre> 
 * {@code 
 *      <dependency>
 *          <groupId>com.google.zxing</groupId>
 *            <artifactId>core</artifactId>
 *            <version>3.4.1</version>
 *        </dependency>
 *        <dependency>
 *            <groupId>com.google.zxing</groupId>
 *            <artifactId>javase</artifactId>
 *            <version>3.4.1</version>
 *        </dependency>
 * }
 * </pre>
 */

public class QrCodeExtractor {
    public static void main(String[] args) throws IOException, NotFoundException, ChecksumException, FormatException, URISyntaxException {
        BinaryBitmap image = new BinaryBitmap(new HybridBinarizer(new BufferedImageLuminanceSource(ImageIO.read(new File(args[0])))));
        Result result = new QRCodeReader().decode(image);
        String[] queryParams = new URI(result.getText()).getQuery().split("&");
        for (String queryParam : queryParams) {
            String[] keyAndValue = queryParam.split("=", 2);
            if(keyAndValue.length > 1 && keyAndValue[0].equals("secret"))
                System.out.println(keyAndValue[1]);
        }
    }
}