How to resolve .net core 3.1 json deserialization exception.

kishore kumar 1

Dear Experts,

Please help me to resolve this below exception.

I am using .net core 3.1 System.Text.Json namespace, I don't want to use third party components.

string jsonStr= "{  \"name1\": \"test\",  \"key\": \"test2\",  \"args\": {    \"value\": \"%PDF-1.4 Scanned ImagePDF%Non-Encryption3 0 obj<</Type /Page/Parent 1 0 R/Resources 4 0 R/Contents 5 0 R/MediaBox [0 0 613 790]>>endobj4 0 obj<</ProcSet [/PDF /ImageB]/XObject << /Img1 6 0 R >>>>endobj5 0 obj<</Length 27>>stream613 0 0 790 0 0 cm/Img1 Doendstreamendobj6 0 obj<</Type /XObject/Subtype /Image/Name /Img1/Filter /CCITTFaxDecode/DecodeParms <<  /K -1 /Columns 1704 /Rows 2196 >>/Width 1704/Height 2196/BitsPerComponent 1/ColorSpace /DeviceGray/Length 7 0 R>>stream_�������W]������}�Y���������W��_����������)�����������������������������������������!|�P!E�;!a̝��0�fC@@ h`�gNKb���@����<&�M�au�D<�;D??KDB:D\"*��?�oA�A����}&�6�;�zo����:o����+�'�m'���������W�Q��C#G���*�`C�xDX��PEx����N�F�Π�0\\�j ���=<q[c��\\ xA��a��M�m��\t��/�^�ڽ�A���Z!0������8\"?������Bg���P�`�?�^\"a�o�,6�> ����� l�PA�&��`�A�>�a�?�uG���_���a{ @0�I��dŲ�����I��؞��'݃I�>�u���{�����ޟ����5��a�������0��^���L������=��YIA����8�Z ���\"  }}";
    var data = JsonSerializer.Deserialize<Dictionary<string, object>>(jsonStr);

The above code not able to desterilize to an Dictionary<string, object> type.
Here in the json string value key contains the pdf file data, it may have some unprintable characters also.

Can you please help us to resolve deserilize to a dictionary.

Best Regards,
Kumar

Viorel 117.6K Reputation points

2021-07-28T10:57:59.577+00:00

Are you sure that this JSON string is valid? How was it obtained?

Show your code and the error messages.
kishore kumar 1 Reputation point

2021-07-29T06:30:55.827+00:00

I prepared json string manually. the json data contains non printable characters, deserialization is failed.
Is there any way to De serialize the json data which contains non printable characters.

Regards,
Kumar
Viorel 117.6K Reputation points

2021-07-29T07:19:09.593+00:00

Maybe you should consider a different format of value. For example, you can get an array (in case of PDF files, use File.ReadAllBytes), represent it as text using Convert.ToBase64String, then use it in JSON. The deserialisation should work. You can use Convert.FromBase64String to obtain the PDF bytes after deserialisation.
kishore kumar 1 Reputation point

2021-07-29T08:49:54.53+00:00

Thank you very much for your help.
I will check and update this approach.
Daniel Zhang-MSFT 9,626 Reputation points

2021-08-04T01:14:09+00:00

Hi @kishore kumar ,
May I know whether your issue has been solved or not? If not, please share it in here. We can work together to figure it out.
Best Regards,
Daniel Zhang
kishore kumar 1 Reputation point

2021-08-13T13:18:52.423+00:00

Dear Daniel Zhang,

Thank you for your comment.

Maybe you should consider a different format of value. For example, you can get an array (in case of PDF files, use File.ReadAllBytes), represent it as text using Convert.ToBase64String, then use it in JSON. The deserialisation should work. You can use Convert.FromBase64String to obtain the PDF bytes after deserialisation.

The thing is json string is received from the C code to C# code, It is not in C# language control.
Now I changed the approach, I am getting the json value using C# regex. So no need of deserialization of json string.

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