Use Java to generate QR codes with text

Introduction

Mainly uses goole’s zxing package. The sample code is given below, which is very convenient for everyone to understand and learn. The codes are all preliminary frameworks. The functions are available and need to be optimized according to the actual usage. .

First step, maven import zxing

<dependency>
 <groupId>com.google.zxing</groupId>
 <artifactId>core</artifactId>
 <version>3.2.1</version>
</dependency>

Second step, start generating QR code:

private static final int BLACK = 0xFF000000;
private static final int WHITE = 0xFFFFFFFF;
/**
 * 把生成的二维码存入到图片中
 * @param matrix zxing包下的二维码类
 * @return
 */
public static BufferedImage toBufferedImage(BitMatrix matrix) {
 int width = matrix.getWidth();
 int height = matrix.getHeight();
 BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
 for (int x = 0; x < width; x++) {
  for (int y = 0; y < height; y++) {
   image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
  }
 }
 return image;
}
/**
 * 生成二维码并写入文件
 * @param content 扫描二维码的内容
 * @param format 图片格式 jpg
 * @param file  文件
 * @throws Exception
 */
public static void writeToFile(String content, String format, File file)
  throws Exception {
 MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
 @SuppressWarnings("rawtypes")
 Map hints = new HashMap();
 //设置UTF-8， 防止中文乱码
 hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
 //设置二维码四周白色区域的大小
 hints.put(EncodeHintType.MARGIN,1);
 //设置二维码的容错性
 hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
 //画二维码
 BitMatrix bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, WIDTH, HEIGHT, hints);
 BufferedImage image = toBufferedImage(bitMatrix);
 if (!ImageIO.write(image, format, file)) {
  throw new IOException("Could not write an image of format " + format + " to " + file);
 }
}

The third step, write the text into the QR code image:

/**
 * 给二维码图片加上文字
 * @param pressText 文字
 * @param qrFile  二维码文件
 * @param fontStyle
 * @param color
 * @param fontSize
 */
public static void pressText(String pressText, File qrFile, int fontStyle, Color color, int fontSize) throws Exception {
 pressText = new String(pressText.getBytes(), "utf-8");
 Image src = ImageIO.read(qrFile);
 int imageW = src.getWidth(null);
 int imageH = src.getHeight(null);
 BufferedImage image = new BufferedImage(imageW, imageH, BufferedImage.TYPE_INT_RGB);
 Graphics g = image.createGraphics();
 g.drawImage(src, 0, 0, imageW, imageH, null);
 //设置画笔的颜色
 g.setColor(color);
 //设置字体
 Font font = new Font("宋体", fontStyle, fontSize);
 FontMetrics metrics = g.getFontMetrics(font);
 //文字在图片中的坐标 这里设置在中间
 int startX = (WIDTH - metrics.stringWidth(pressText)) / 2;
 int startY = HEIGHT/2;
 g.setFont(font);
 g.drawString(pressText, startX, startY);
 g.dispose();
 FileOutputStream out = new FileOutputStream(qrFile);
 ImageIO.write(image, "JPEG", out);
 out.close();
 System.out.println("image press success");
}

The fourth step, test it in the main method, a 2D code with text in the middle The code is generated

public static void main(String[] args) throws Exception {
 File qrcFile = new File("/Users/deweixu/","google.jpg");
 writeToFile("www.google.com.hk", "jpg", qrcFile);
 pressText("谷歌", qrcFile, 5, Color.RED, 32);
}

Summary

The above is the entire content of this article. I hope the content of this article can bring some help to everyone's study or work. , if you have any questions, you can leave a message to communicate.

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