二维码生成教程

<!--    二维码工具类-->
    <!-- https://mvnrepository.com/artifact/com.google.zxing/core -->
    <dependency>
      <groupId>com.google.zxing</groupId>
      <artifactId>core</artifactId>
      <version>3.3.3</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.google.zxing/javase -->
    <dependency>
      <groupId>com.google.zxing</groupId>
      <artifactId>javase</artifactId>
      <version>3.3.3</version>
    </dependency>

String content = "htttps://www.baidu.com";//二维码内容
int width = 200; // 图像宽度
int height = 200; // 图像高度
String format = "png";// 图像类型
Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
//内容编码格式
hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
// 指定纠错等级
hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
//设置二维码边的空度，非负数
hints.put(EncodeHintType.MARGIN, 2);
BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, width, height, hints); //写到输出流里
MatrixToImageWriter.writeToStream(bitMatrix,format,response.getOutputStream());
System.out.println("二维码生成成功");