Android Base64加密图片

public static String getImageStr(String imgFile) throws IOException {
    InputStream inputStream = null;
    byte[] data = null;

    inputStream = new FileInputStream(imgFile);
    data = new byte[inputStream.available()];
    inputStream.read(data);
    inputStream.close();
    // 加密
    String activation64 = Base64.encodeToString(data, Base64.DEFAULT);
    return activation64;
}

 public Bitmap stringtoBitmap(String string) {
        //将字符串转换成Bitmap类型
        Bitmap bitmap = null;
        try {
            byte[] bitmapArray;
            bitmapArray = Base64.decode(string, Base64.DEFAULT);
            bitmap = BitmapFactory.decodeByteArray(bitmapArray, 0, bitmapArray.length);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return bitmap;
    }


    public String bitmaptoString(Bitmap bitmap) {
        //将Bitmap转换成字符串
        String string = null;
        ByteArrayOutputStream bStream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, bStream);
        byte[] bytes = bStream.toByteArray();
        string = Base64.encodeToString(bytes, Base64.DEFAULT);
        return string;
    }