java利用zxing生成二维码

谁借莪１个温暖的怀抱￠ 2022-06-14 06:50 294阅读 0赞

# java利用zxing生成二维码 #

> 环境：IntelliJ IDEA 2016.3.4(64)、jdk1.7

#### 创建maven工程 ####

pom文件内容如下：

<?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>
 
 <groupId>cn.ja.rome</groupId>
 <artifactId>qrtest</artifactId>
 <version>1.0-SNAPSHOT</version>
 
 <dependencies>
 <dependency>
 <groupId>org.apache.commons</groupId>
 <artifactId>commons-io</artifactId>
 <version>1.3.2</version>
 </dependency>
 <dependency>
 <groupId>com.google.zxing</groupId>
 <artifactId>core</artifactId>
 <version>3.1.0</version>
 </dependency>
 <dependency>
 <groupId>com.google.zxing</groupId>
 <artifactId>javase</artifactId>
 <version>3.1.0</version>
 </dependency>
 </dependencies>
 </project>

ZxingUtils.java

package cn.ja.rome.qrcode;
 
 import java.awt.image.BufferedImage;
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Hashtable;
 import java.util.Map;
 
 import javax.imageio.ImageIO;
 
 import org.apache.commons.io.output.ByteArrayOutputStream;
 
 import com.google.zxing.BarcodeFormat;
 import com.google.zxing.BinaryBitmap;
 import com.google.zxing.DecodeHintType;
 import com.google.zxing.EncodeHintType;
 import com.google.zxing.LuminanceSource;
 import com.google.zxing.MultiFormatReader;
 import com.google.zxing.MultiFormatWriter;
 import com.google.zxing.ReaderException;
 import com.google.zxing.Result;
 import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
 import com.google.zxing.common.BitMatrix;
 import com.google.zxing.common.HybridBinarizer;
 
 /** * 利用zxing开源工具生成二维码QRCode */
 public class ZxingQrcode { 
 
 /** * 填充颜色 */
 private static final int BLACK = 0xff000000;
 private static final int WHITE = 0xFFFFFFFF;
 
 
 /** * 生成QRCode二维码 * 在编码时需要将com.google.zxing.qrcode.encoder.Encoder.java中的 * static final String DEFAULT_BYTE_MODE_ENCODING = "ISO8859-1"; * 修改为UTF-8，否则中文编译后解析不了 */
 public void encode(String contents, File file, BarcodeFormat format, int width, int height,
 Map<EncodeHintType, ?> hints) {
 try {
 // 消除乱码
 contents = new String(contents.getBytes("UTF-8"), "ISO-8859-1");
 BitMatrix bitMatrix = new MultiFormatWriter().encode(contents, format, width, height);
 writeToFile(bitMatrix, "png", file);
 } catch (Exception e) {
 e.printStackTrace();
 }
 }
 
 /** * 生成二维码图片 * * @param matrix * @param format 图片格式 * @param file 生成二维码图片位置 * @throws IOException */
 public static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {
 BufferedImage image = toBufferedImage(matrix);
 ImageIO.write(image, format, file);
 }
 
 /** * 生成二维码内容 * * @param matrix * @return */
 public static BufferedImage toBufferedImage(BitMatrix matrix) {
 int width = matrix.getWidth();
 int height = matrix.getHeight();
 BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
 for (int x = 0; x < width; x++) {
 for (int y = 0; y < height; y++) {
 image.setRGB(x, y, matrix.get(x, y) == true ? BLACK : WHITE);
 }
 }
 return image;
 }
 
 /** * 解析QRCode二维码 */
 @SuppressWarnings("unchecked")
 public void decode(File file) {
 try {
 BufferedImage image;
 try {
 image = ImageIO.read(file);
 if (image == null) {
 System.out.println("Could not decode image");
 }
 LuminanceSource source = new BufferedImageLuminanceSource(image);
 BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
 Result result;
 @SuppressWarnings("rawtypes")
 Hashtable hints = new Hashtable();
 // 解决com.google.zxing.NotFoundException异常
 // 解码设置编码方式为：utf-8
 hints.put(DecodeHintType.CHARACTER_SET, "utf-8");
 //优化精度
 hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
 //复杂模式，开启PURE_BARCODE模式
 hints.put(DecodeHintType.PURE_BARCODE, Boolean.TRUE);
 result = new MultiFormatReader().decode(bitmap, hints);
 String resultStr = result.getText();
 System.out.println("解析后内容：" + resultStr);
 } catch (IOException ioe) {
 System.out.println(ioe.toString());
 } catch (ReaderException re) {
 System.out.println(re.toString());
 }
 } catch (Exception ex) {
 System.out.println(ex.toString());
 }
 }
 
 /** * BufferedImage 转为 InputStream * * @param image * @return */
 public static InputStream getImageStream(BufferedImage image) {
 try {
 ByteArrayOutputStream os = new ByteArrayOutputStream();
 ImageIO.write(image, "png", os);
 InputStream is = new ByteArrayInputStream(os.toByteArray());
 return is;
 } catch (IOException e) {
 e.printStackTrace();
 return null;
 }
 }
 }

TestEnCode.java 生成二维码

package cn.ja.rome.qrcode;
    
    import com.google.zxing.BarcodeFormat;
    
    import java.io.File;
    
    public class TestEnCode { 
    
        static String filePath = "D:/qrcode";
    
        public static void main(String[] args) {
            ZxingQrcode zxing = new ZxingQrcode();
            File file = new File(filePath, "test.png");
            String content = "http://blog.csdn.net/jlh912008548/article/details/72943741";
            zxing.encode(content, file, BarcodeFormat.QR_CODE, 400, 400);
        }
    }

打开windowx资源管理器，查看D:/qrcode/test.png  
![二维码][SouthEast]  
使用微信扫描该二维码，内容如下：  
![微信扫描结果][SouthEast 1]

读取二维码：

static String filePath = "D:/qrcode/test.png";
        public static void main(String[] args) {
            ZxingQrcode zxing = new ZxingQrcode();
            File file = new File(filePath);
            zxing.decode(file);
        }

控制台输出：解析后内容：[http://blog.csdn.net/jlh912008548/article/details/72943741][http_blog.csdn.net_jlh912008548_article_details_72943741]

#### 遇见的问题 ####

在读取二维码的时候抛出这样一个异常：com.google.zxing.NotFoundException，在查阅资料后发现我在生成二维码的时候白色像素填充使用的是透明色，这样在显示的时候因为背景是白色，所以看上去和用手机扫都没有问题，但是自己代码识别的时候就会把透明色识别为黑色，这样就导致整个二维码图片全是黑色像素，所以zxing抛出com.google.zxing.NotFoundException异常。

#### 解决办法 ####

1.  设置编码 hints.put(DecodeHintType.CHARACTER\_SET, CHARSET);
2.  优化精度 hints.put(DecodeHintType.TRY\_HARDER, Boolean.TRUE);
3.  开启PURE\_BARCODE模式 hints.put(DecodeHintType.PURE\_BARCODE, Boolean.TRUE);

实例见ZxingQrcode类的decode方法

[SouthEast]: /images/20220614/fa30600958b64339a88bfba9d01c2cfd.png
[SouthEast 1]: /images/20220614/8c11a5d981b74bbbaa710d9d844fb343.png
[http_blog.csdn.net_jlh912008548_article_details_72943741]: http://blog.csdn.net/jlh912008548/article/details/72943741