38

好的，所以我要排除这里有人以前使用过 zxing 的机会。我正在开发一个 Java 应用程序，它需要做的一件事就是将一个字节数组的数据编码成一个二维码，然后在以后对其进行解码。

这是我的编码器的示例：

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);

此代码中的开始字节数组仅用于测试它。实际的字节数据会有所不同。

这是我的解码器的样子：

//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)是一种将字节数组转换为十六进制字符串的方法。

当我尝试同时运行这两个代码块时，输出如下：

48454c4c4f
202b0b78cc00ec11ec11ec11ec11ec11ec11ec

很明显，文本正在被编码，但数据的实际字节完全没有。任何帮助将不胜感激。

4

6 回答 6

53

因此，对于那些不想花两天时间在互联网上搜索来弄清楚这一点的人来说，为了将来参考，当您将字节数组编码为 QR 码时，您必须使用ISO-8859-1字符集，而不是UTF-8.

于 2010-03-22T01:58:20.713 回答
19

this is my working example Java code to encode QR code using ZXing with UTF-8 encoding, please note: you will need to change the path and utf8 data to your path and language characters 

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());
    }
}

}
于 2011-10-13T15:58:07.820 回答
6

对于它的价值，我的 groovy 尖峰似乎适用于 UTF-8 和 ISO-8859-1 字符编码。不确定当非 zxing 解码器尝试解码 UTF-8 编码图像时会发生什么……可能因设备而异。

// ------------------------------------------------------------------------------------
// 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()        
    }

}
于 2011-11-25T23:07:13.363 回答
1

如第一个答案中所述，我尝试使用 ISO-8859-1。编码一切正常，但是当我尝试在解码时使用结果字符串获取 byte[] 时，所有负字节都变成了字符 63（问号）。以下代码不起作用：

// 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;

它看起来很奇怪，因为一个非常旧的版本（不确切知道）中的 API 有一个方法 thar 效果很好：

Vector byteSegments = result.getByteSegments();

所以我试图搜索为什么这个方法被删除并意识到有一种方法可以通过元数据获取 ByteSegments。所以我的解码方法看起来像：

// 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;
于 2011-02-13T01:09:06.393 回答
1

如果您确实需要编码 UTF-8，可以尝试在 unicode 字节顺序标记之前添加。我不知道对这种方法的支持有多广泛，但 ZXing 至少似乎支持它： http ://code.google.com/p/zxing/issues/detail?id=103

我最近一直在阅读 QR 模式，我想我在其他地方也看到过同样的做法，但我没有最模糊的地方。

于 2010-03-29T20:42:06.790 回答
1

也许值得看一下QRGen，它建立在 ZXing 之上并支持 UTF-8 的这种语法：

// 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();
于 2014-06-12T08:10:04.300 回答