QR码编码和使用的解码斑马线

Question

好了，所以我要采取关闭的机会，有人在这里使用了斑马线前。我正在开发一个Java应用程序，以及它需要做的事情之一是编码的字节数组数据转换为QR码，然后在以后的时间进行解码。

下面就是我的编码器的样子的例子：

byte[] b = {0x48, 0x45, 0x4C, 0x4C, 0x4F};
//convert the byte array into a UTF-8 string
String data;
try {
    data = new String(b, "UTF8");
}
catch (UnsupportedEncodingException e) {
 //the program shouldn't be able to get here
 return;
}

//get a byte matrix for the data
ByteMatrix matrix;
com.google.zxing.Writer writer = new QRCodeWriter();
try {
 matrix = writer.encode(data, com.google.zxing.BarcodeFormat.QR_CODE, width, height);
}
catch (com.google.zxing.WriterException e) {
 //exit the method
 return;
}

//generate an image from the byte matrix
int width = matrix.getWidth(); 
int height = matrix.getHeight(); 

byte[][] array = matrix.getArray();

//create buffered image to draw to
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

//iterate through the matrix and draw the pixels to the image
for (int y = 0; y < height; y++) { 
 for (int x = 0; x < width; x++) { 
  int grayValue = array[y][x] & 0xff; 
  image.setRGB(x, y, (grayValue == 0 ? 0 : 0xFFFFFF));
 }
}

//write the image to the output stream
ImageIO.write(image, "png", outputStream);

在此代码的开始的字节数组只是用来进行测试。实际的字节数据将被改变。

下面就是我的解码器看起来像：

//get the data from the input stream
BufferedImage image = ImageIO.read(inputStream);

//convert the image to a binary bitmap source
LuminanceSource source = new BufferedImageLuminanceSource(image);
BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));

//decode the barcode
QRCodeReader reader = new QRCodeReader();

Result result;
try {
 result = reader.decode(bitmap, hints);
} catch (ReaderException e) {
 //the data is improperly formatted
 throw new MCCDatabaseMismatchException();
}

byte[] b = result.getRawBytes();
System.out.println(ByteHelper.convertUnsignedBytesToHexString(result.getText().getBytes("UTF8")));
System.out.println(ByteHelper.convertUnsignedBytesToHexString(b));

convertUnsignedBytesToHexString(byte)是其将字节数组中的十六进制字符的字符串的方法。

当我尝试运行的代码一起这些两个块，这是输出：

48454c4c4f
202b0b78cc00ec11ec11ec11ec11ec11ec11ec

显然，文本被编码，但实际的数据字节是完全关闭。任何帮助，将这里理解。

Answer 1

因此，对于任何人谁不希望花费两天时间搜索互联网摸不着头脑，当你编码的字节数组到QR码备查，您必须使用ISO-8859-1character集，不UTF-8。

Answer 2

这是用斑马线用UTF-8编码我工作示例Java代码编码QR码，请注意：您需要的路径和UTF8数据更改为您的路径和语言文字

package com.mypackage.qr;

import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.util.Hashtable;

import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.*;

public class CreateQR {

public static void main(String[] args)
{
    Charset charset = Charset.forName("UTF-8");
    CharsetEncoder encoder = charset.newEncoder();
    byte[] b = null;
    try {
        // Convert a string to UTF-8 bytes in a ByteBuffer
        ByteBuffer bbuf = encoder.encode(CharBuffer.wrap("utf 8 characters - i used hebrew, but you should write some of your own language characters"));
        b = bbuf.array();
    } catch (CharacterCodingException e) {
        System.out.println(e.getMessage());
    }

    String data;
    try {
        data = new String(b, "UTF-8");
        // get a byte matrix for the data
        BitMatrix matrix = null;
        int h = 100;
        int w = 100;
        com.google.zxing.Writer writer = new MultiFormatWriter();
        try {
            Hashtable<EncodeHintType, String> hints = new Hashtable<EncodeHintType, String>(2);
            hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
            matrix = writer.encode(data,
            com.google.zxing.BarcodeFormat.QR_CODE, w, h, hints);
        } catch (com.google.zxing.WriterException e) {
            System.out.println(e.getMessage());
        }

        // change this path to match yours (this is my mac home folder, you can use: c:\\qr_png.png if you are on windows)
                String filePath = "/Users/shaybc/Desktop/OutlookQR/qr_png.png";
        File file = new File(filePath);
        try {
            MatrixToImageWriter.writeToFile(matrix, "PNG", file);
            System.out.println("printing to " + file.getAbsolutePath());
        } catch (IOException e) {
            System.out.println(e.getMessage());
        }
    } catch (UnsupportedEncodingException e) {
        System.out.println(e.getMessage());
    }
}

}

Answer 3

有关它的价值，我的常规秒杀似乎与UTF-8和ISO-8859-1字符编码都工作。不知道什么时候会发生非斑马线解码器尝试虽然...根据设备的可能变化的UTF-8编码的图像进行解码。

// ------------------------------------------------------------------------------------
// Requires: groovy-1.7.6, jdk1.6.0_03, ./lib with zxing core-1.7.jar, javase-1.7.jar 
// Javadocs: http://zxing.org/w/docs/javadoc/overview-summary.html
// Run with: groovy -cp "./lib/*" zxing.groovy
// ------------------------------------------------------------------------------------

import com.google.zxing.*
import com.google.zxing.common.*
import com.google.zxing.client.j2se.*

import java.awt.image.BufferedImage
import javax.imageio.ImageIO

def class zxing {
    def static main(def args) {
        def filename = "./qrcode.png"
        def data = "This is a test to see if I can encode and decode this data..."
        def charset = "UTF-8" //"ISO-8859-1" 
        def hints = new Hashtable<EncodeHintType, String>([(EncodeHintType.CHARACTER_SET): charset])

        writeQrCode(filename, data, charset, hints, 100, 100)

        assert data == readQrCode(filename, charset, hints)
    }

    def static writeQrCode(def filename, def data, def charset, def hints, def width, def height) {
        BitMatrix matrix = new MultiFormatWriter().encode(new String(data.getBytes(charset), charset), BarcodeFormat.QR_CODE, width, height, hints)
        MatrixToImageWriter.writeToFile(matrix, filename.substring(filename.lastIndexOf('.')+1), new File(filename))
    }

    def static readQrCode(def filename, def charset, def hints) {
        BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(new BufferedImageLuminanceSource(ImageIO.read(new FileInputStream(filename)))))
        Result result = new MultiFormatReader().decode(binaryBitmap, hints)

        result.getText()        
    }

}

Answer 4

也许值得看 QRGen ，该构建在斑马线的顶部和支撑件UTF-8与此种语法：

// if using special characters don't forget to supply the encoding
VCard johnSpecial = new VCard("Jöhn Dɵe")
                        .setAdress("ëåäöƞ Sträät 1, 1234 Döestüwn");
QRCode.from(johnSpecial).withCharset("UTF-8").file();

Answer 5

如果你真的需要编码UTF-8，你可以尝试在前面加上Unicode字节顺序标记。我不知道这种方法的支持有多普遍，但斑马线至少出现来支持它： http://code.google.com/p/zxing/issues/细节？ID = 103

我一直在QR模式下阅读了最近，我的认为的我已经看到了同样的做法在其他地方提到，但我一点都不知道在哪里。

Answer 6

我尝试使用ISO-8859-1如在第一答案所述。一切都很OK的编码，但是当我试图让使用结果字符串解码上的[]字节，所有负字节成为字符63（问号）。下面的代码不工作：

// 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;

这看起来很奇怪，因为在一个很旧版本的API（并不确切地知道）有塔尔行之有效的方法：

Vector byteSegments = result.getByteSegments();

于是，我试图寻找为什么要被移除，并意识到有一种方式来获得ByteSegments，通过元数据这种方法。所以，我的解码方法如下：

// 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;