二維碼生成工具類
  
  public class QRCodeUtil {
/**
 * 生成二維碼Bitmap
 *
 * @param content   內(nèi)容
 * @param widthPix  圖片寬度
 * @param heightPix 圖片高度
 * @param logoBm    二維碼中心的Logo圖標(biāo)（可以為null）
 * @param filePath  用于存儲(chǔ)二維碼圖片的文件路徑
 * @return 生成二維碼及保存文件是否成功
 */
public static boolean createQRImage(String content, int widthPix, int heightPix,
                                    Bitmap logoBm, String filePath) {
    try {
        if (content == null || "".equals(content)) {
            return false;
        }

        //配置參數(shù)
        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        //容錯(cuò)級(jí)別
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        //設(shè)置空白邊距的寬度
        hints.put(EncodeHintType.MARGIN, 1); //default is 4

        // 圖像數(shù)據(jù)轉(zhuǎn)換盖呼，使用了矩陣轉(zhuǎn)換
        BitMatrix bitMatrix = null;
        try {
            bitMatrix = new QRCodeWriter().encode(content, BarcodeFormat.QR_CODE, widthPix,
                    heightPix, hints);
        } catch (WriterException e) {
            e.printStackTrace();
        }
        int[] pixels = new int[widthPix * heightPix];
        // 下面這里按照二維碼的算法伞鲫，逐個(gè)生成二維碼的圖片褐缠，
        // 兩個(gè)for循環(huán)是圖片橫列掃描的結(jié)果
        for (int y = 0; y < heightPix; y++) {
            for (int x = 0; x < widthPix; x++) {
                if (bitMatrix.get(x, y)) {
                    pixels[y * widthPix + x] = 0xff000000;
                } else {
                    pixels[y * widthPix + x] = 0xffffffff;
                }
            }
        }

        // 生成二維碼圖片的格式懊直，使用RGB_565
        Bitmap bitmap = Bitmap.createBitmap(widthPix, heightPix, Bitmap.Config.RGB_565);
        bitmap.setPixels(pixels, 0, widthPix, 0, 0, widthPix, heightPix);

        if (logoBm != null) {
            bitmap = addLogo(bitmap, logoBm);
        }

        //必須使用compress方法將bitmap保存到文件中再進(jìn)行讀取笔宿。直接返回的bitmap是沒有任何壓縮的，
        // 內(nèi)存消耗巨大稳摄！
        return bitmap != null && bitmap.compress(Bitmap.CompressFormat.JPEG, 100,
                new FileOutputStream(filePath));
    } catch (Exception e) {
        e.printStackTrace();
    }

    return false;
}

/**
 * 在二維碼中間添加Logo圖案
 */
private static Bitmap addLogo(Bitmap src, Bitmap logo) {
    if (src == null) {
        return null;
    }

    if (logo == null) {
        return src;
    }

    //獲取圖片的寬高
    int srcWidth = src.getWidth();
    int srcHeight = src.getHeight();
    int logoWidth = logo.getWidth();
    int logoHeight = logo.getHeight();

    if (srcWidth == 0 || srcHeight == 0) {
        return null;
    }

    if (logoWidth == 0 || logoHeight == 0) {
        return src;
    }

    //logo大小為二維碼整體大小的1/5
    float scaleFactor = srcWidth * 1.0f / 5 / logoWidth;
    Bitmap bitmap = Bitmap.createBitmap(srcWidth, srcHeight, Bitmap.Config.ARGB_8888);
    try {
        Canvas canvas = new Canvas(bitmap);
        canvas.drawBitmap(src, 0, 0, null);
        canvas.scale(scaleFactor, scaleFactor, srcWidth / 2, srcHeight / 2);
        canvas.drawBitmap(logo, (srcWidth - logoWidth) / 2, (srcHeight - logoHeight) / 2, null);

        canvas.save(Canvas.ALL_SAVE_FLAG);
        canvas.restore();
    } catch (Exception e) {
        bitmap = null;
        e.getStackTrace();
    }

    return bitmap;
}

/**
 * Bitmap轉(zhuǎn)換成byte[]并且進(jìn)行壓縮,壓縮到不大于maxkb
 * @param bitmap
 * @param maxkb
 * @return
 */
public static byte[] bitmap2Bytes(Bitmap bitmap, int maxkb) {
    ByteArrayOutputStream output = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, output);
    int options = 100;
    while (output.toByteArray().length > maxkb&& options != 10) {
        output.reset(); //清空output
        bitmap.compress(Bitmap.CompressFormat.JPEG, options, output);//這里壓縮options%稚字，把壓縮后的數(shù)據(jù)存放到output中
        options -= 10;
    }
    return output.toByteArray();
}

}

轉(zhuǎn)自某篇文章（已找不到出處，如有人知曉請(qǐng)告訴我厦酬，會(huì)附上原創(chuàng)鏈接）