implementation 'com.google.zxing:core:3.4.1'

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.4.1</version>
</dependency>

import com.google.zxing.*
import com.google.zxing.common.HybridBinarizer
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel
import java.awt.geom.AffineTransform
import java.awt.image.BufferedImage


object QrUtil {
    private val mfw = MultiFormatWriter()
    private val encodeHints = object : HashMap<EncodeHintType, Any>() {
        init {
            put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H)
            put(EncodeHintType.CHARACTER_SET, Charsets.UTF_8)
            put(EncodeHintType.MARGIN, 1)
        }
    }
    
    private val decodeHints = object : HashMap<DecodeHintType, Any>() {
        init {
            put(DecodeHintType.CHARACTER_SET, Charsets.UTF_8)
            //优化精度
            put(DecodeHintType.TRY_HARDER, true)
            //复杂模式，开启PURE_BARCODE模式
            put(DecodeHintType.PURE_BARCODE, true)
        }
    }

    /**
     * 生成二维码
     *
     * 若宽/高小于生成的二维码的最小宽度则会忽略此宽/高度, 否则会生成此宽/高度的二维码图片
     *
     * @param content 正文
     * @param width 目标图片宽度
     * @param height 目标图片高度
     * @param color1 二维码颜色
     * @param color2 二维码背景
     * @return 二维码图片
     */
    @Throws(WriterException::class)
    fun getQrImage(
        content: String,
        width: Int,
        height: Int,
        color1: Int,
        color2: Int,
    ): BufferedImage {
        val bitMatrix = mfw.encode(content, BarcodeFormat.QR_CODE, width, height, encodeHints)
        val w = bitMatrix.width
        val h = bitMatrix.height
        val image = BufferedImage(w, h, 1)
        for (x in 0 until w) for (y in 0 until h) image.setRGB(x, y, if (bitMatrix[x, y]) color1 else color2)
        return image
    }

    /**
     * 识别二维码
     *
     * @param image 要识别的图片
     * @return 识别的结果
     */
    @Throws(NotFoundException::class)
    fun decode(image: BufferedImage): String {
        val source = BufferedImageLuminanceSource(image)
        val bitmap = BinaryBitmap(HybridBinarizer(source))
        return MultiFormatReader().decode(bitmap, decodeHints).text
    }

    class BufferedImageLuminanceSource(
        image: BufferedImage,
        left: Int = 0,
        top: Int = 0,
        width: Int = image.width,
        height: Int = image.height,
    ) :
        LuminanceSource(width, height) {
        private val image: BufferedImage
        private val left: Int
        private val top: Int
        override fun getRow(y: Int, rowBytes: ByteArray): ByteArray {
            var row = rowBytes
            require(!(y < 0 || y >= height)) { "Requested row is outside the image: $y" }
            if (row.size < width) row = ByteArray(width)
            image.raster.getDataElements(left, top + y, width, 1, row)
            return row
        }

        override fun getMatrix(): ByteArray {
            val width = width
            val height = height
            val area = width * height
            val matrix = ByteArray(area)
            image.raster.getDataElements(left, top, width, height, matrix)
            return matrix
        }

        override fun isCropSupported() = true
        override fun crop(left: Int, top: Int, width: Int, height: Int) =
            BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height)

        override fun isRotateSupported() = true

        override fun rotateCounterClockwise(): LuminanceSource {
            val sourceWidth = image.width
            val sourceHeight = image.height
            val transform = AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth.toDouble())
            val rotatedImage = BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY)
            val g = rotatedImage.createGraphics()
            g.drawImage(image, transform, null)
            g.dispose()
            val width = width
            return BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), height, width)
        }

        init {
            val sourceWidth = image.width
            val sourceHeight = image.height
            require(!(left + width > sourceWidth || top + height > sourceHeight)) { "Crop rectangle does not fit within image data." }
            for (y in top until top + height) {
                for (x in left until left + width) {
                    if (image.getRGB(x, y) and -0x1000000 == 0) {
                        image.setRGB(x, y, -0x1) // = white
                    }
                }
            }
            this.image = BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY)
            this.image.graphics.drawImage(image, 0, 0, null)
            this.left = left
            this.top = top
        }
    }
}

<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>test</title>
</head>
<body>
    <div id="main"></div>
</body>
</html>

function load(title) {
  // div
  let div = document.createElement("div");
  div.setAttribute("class", "test")
  // h2
  let h2 = document.createElement("h2");
  h2.appendChild(document.createTextNode("标题: " + title));
  div.appendChild(h2);
  // 添加
  document.getElementById("main").appendChild(div);
}

// 设置初始时间
let time = new Date().getTime();
// 监听器
function eventHandle(e) {
  // 这里设置一个时间,原因是每次浏览器滚动条位置变动都会出发event
  // 加载较慢时可能会出现滚动条到底了,第一次触发的内容还未加载出来
  // 这里设置每200ms可以触发一次
  let t = new Date().getTime();
  if (t - time > 200) {
    time = t;
    // 浏览器上方内容的高度
    let viewportHeight = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight || 0;
    // 页面总高度
    let pageHeight = Math.max(document.body.scrollHeight, document.body.offsetHeight) - viewportHeight;
    // 滚动条高度
    let scrollHeight = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0;
    // 当页面浏览进度超过90%时使用鼠标滚轮触发
    if (scrollHeight / pageHeight > 0.9) load("awa");
  }
}
// 启用监听器 scroll是监听器名字
document.addEventListener('scroll', eventHandle);
// 删除监听器
document.removeEventListener('scroll', eventHandle);

<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>test</title>
    <style>
        #main {
            height: 1200px;
        }

        .test {
            height: 200px;
        }
    </style>
</head>
<body>
    <div id="main"></div>
    <script>
        function load(title) {
            // div
            let div = document.createElement("div");
            div.setAttribute("class", "test")
            // h2
            let h2 = document.createElement("h2");
            h2.appendChild(document.createTextNode("标题: " + title));
            div.appendChild(h2);
            // 添加
            document.getElementById("main").appendChild(div);
        }
        load("awa");
        // 设置初始时间
        let time = new Date().getTime();
        // 监听器
        let count = 1;
        function eventHandle(e) {
            // 这里设置一个时间,原因是每次浏览器滚动条位置变动都会出发event
            // 加载较慢时可能会出现滚动条到底了,第一次触发的内容还未加载出来
            // 这里设置每200ms可以触发一次
            let t = new Date().getTime();
            if (t - time > 200) {
                time = t;
                // 浏览器上方内容的高度
                let viewportHeight = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight || 0;
                // 页面总高度
                let pageHeight = Math.max(document.body.scrollHeight, document.body.offsetHeight) - viewportHeight;
                // 滚动条高度
                let scrollHeight = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0;
                // 当页面浏览进度超过90%时使用鼠标滚轮触发
                if (scrollHeight / pageHeight > 0.9) {
                    for (let i = 0; i < 5; i++) {
                        load("第" + count + "次自动加载");
                    }
                    count++;
                }
            }
        }
        // 启用监听器 scroll是监听器名字
        document.addEventListener('scroll', eventHandle);
        // 删除监听器
        // document.removeEventListener('scroll', eventHandle);
    </script>
</body>
</html>