二维码解码编码

pom引入包：

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.4.0</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.4.0</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.4.0</version>
</dependency>

/**
 * 解析图片文件上的二维码
 *
 * @param imageFile 图片文件
 * @return 解析的结果，null表示解析失败
 */
private static String decode(File imageFile) {
    try {
        BufferedImage image = ImageIO.read(imageFile);
        LuminanceSource luminanceSource = new BufferedImageLuminanceSource(image);
        Binarizer binarizer = new HybridBinarizer(luminanceSource);

        BinaryBitmap binaryBitmap = new BinaryBitmap(binarizer);

        Map<DecodeHintType, Object> hints = new HashMap<>();
        hints.put(DecodeHintType.CHARACTER_SET, "utf-8");
        //优化精度
        hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
        hints.put(DecodeHintType.POSSIBLE_FORMATS, BarcodeFormat.QR_CODE);
        //复杂模式
        hints.put(DecodeHintType.PURE_BARCODE, Boolean.TRUE);
        Result result = new QRCodeReader().decode(binaryBitmap, hints);

        return result.getText();
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}

/**
 * Zxing图形码生成工具
 *
 * @param contents        内容
 * @param barcodeFormat   BarcodeFormat对象
 * @param format          图片格式，可选[png,jpg,bmp]
 * @param width           宽
 * @param height          高
 * @param margin          边框间距px
 * @param saveImgFilePath 存储图片的完整位置，包含文件名
 * @return {boolean}
 */
public static boolean encode(String contents, BarcodeFormat barcodeFormat, Integer margin,
                             ErrorCorrectionLevel errorLevel, String format, int width, int height, String saveImgFilePath) {
    Boolean bool = false;
    BufferedImage bufImg;
    Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
    // 指定纠错等级
    hints.put(EncodeHintType.ERROR_CORRECTION, errorLevel);
    hints.put(EncodeHintType.MARGIN, margin);
    hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
    try {
        // contents = new String(contents.getBytes("UTF-8"), "ISO-8859-1");
        BitMatrix bitMatrix = new MultiFormatWriter().encode(contents, barcodeFormat, width, height, hints);
        MatrixToImageConfig config = new MatrixToImageConfig(0xFF000001, 0xFFFFFFFF);
        bufImg = MatrixToImageWriter.toBufferedImage(bitMatrix, config);
        bool = writeToFile(bufImg, format, saveImgFilePath);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return bool;
}

测试方法：

public static void main(String[] args) {
      // 解码
      String result = decode(new File("D:\\微信二维码.jpg"));
      System.out.println("解码二维码：" + result);
      //生成二维码
      String newQrCode = "D://newQrCode.png";
      encode("http://outer.qtoubao.cn/work/card/index.html?sev_no=10002895", BarcodeFormat.QR_CODE, 3, ErrorCorrectionLevel.H, "png", 200, 200,
              newQrCode);
  }