用ZXING生成二维码的工具类（可以去掉白边，添加logo）

===========================用ZXING生成二维码的工具类（可以去掉白边，添加logo）==========================


/**
 * @auther gjc
 * @since 2016/12/27.
 */
public class CreateCodeUtil {

    public static Bitmap createQRImage(String str, int width, int height, Bitmap logoBm) {

        try {
            Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
//            hints.put(EncodeHintType.MARGIN, 1);
            BitMatrix matrix = new QRCodeWriter().encode(str, BarcodeFormat.QR_CODE, width, height);
            matrix = deleteWhite(matrix);//删除白边
            width = matrix.getWidth();
            height = matrix.getHeight();
            int[] pixels = new int[width * height];
            for (int y = 0; y < height; y++) {
                for (int x = 0; x < width; x++) {
                    if (matrix.get(x, y)) {
                        pixels[y * width + x] = Color.BLACK;
                    } else {
                        pixels[y * width + x] = Color.WHITE;
                    }
                }
            }
            Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
            bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
            bitmap = addLogo(bitmap, logoBm);
            return bitmap;
        } catch (Exception e) {
            return null;
        }
    }

    /**
     * 删除白边
     * */
    private static BitMatrix deleteWhite(BitMatrix matrix) {
        int[] rec = matrix.getEnclosingRectangle();
        int resWidth = rec[2] + 1;
        int resHeight = rec[3] + 1;

        BitMatrix resMatrix = new BitMatrix(resWidth, resHeight);
        resMatrix.clear();
        for (int i = 0; i < resWidth; i++) {
            for (int j = 0; j < resHeight; j++) {
                if (matrix.get(i + rec[0], j + rec[1]))
                    resMatrix.set(i, j);
            }
        }
        return resMatrix;
    }

    /**
     * 在二维码中间添加Logo图案
     */
    private static Bitmap addLogo(Bitmap src, Bitmap logo) {
        if (src == null) {
            return null;
        }

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

        //获取图片的宽高
        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大小为二维码整体大小的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;
    }

}