LoadFromStream Fails

[chmichael]

Hello, The SaveFromStream works, but LoadFromStream raise an exception.

[ahausladen]

What Delphi version? What is the exception and where is the location of the exception?

[chmichael]

XE7up1 - the error: unexpected end of file were "{" was expected but found "[".

procedure TJsonReader.AcceptFailed(TokenKind: TJsonTokenKind); begin if FLook.Kind = jtkEof then raise EJsonParserException.CreateResFmt(@RsUnexpectedEndOfFile, [JsonTokenKindToStr[TokenKind]]); raise EJsonParserException.CreateResFmt(@RsUnexpectedToken, [JsonTokenKindToStr[TokenKind], JsonTokenKindToStr[FLook.Kind]]); end;

[ahausladen]

Do you have an example JSON string? My JSON strings all work.

[chmichael]

Just use JsonDataObjectsTest and check only LoadFromStream test.

[ahausladen]

No problem with XE7Up1 and XE8Up1 and the TestLoadFromStream test case on my system. And I don't have local changes in the working copy.

[chmichael]

Here is a sample project: http://we.tl/P0azSt6nOm

[ahausladen]

In your sample project the memory stream is at the end of the stream. So there is nothing to read for LoadFromStream and that's why the EOF exception is thrown.

A "vStringStream.Position := 0;" helps.

But this only gives me "Unexpected end of file where "{" was expected.". You got unexpected end of file were "{" was expected but found "[".. So either the stream that you use in your actual application is at a different position than "end of stream"/"begin of stream" or something else is wrong.

[chmichael]

Ok that was what i forgot to put on the sample ...

The actual problem is that i parse the record into JsonObject (as you can see in my sample) and the i'm trying to save the Json into CLOB field. (CLOB Field: http://www.elevatesoft.com/manual?action=viewtopic&id=edb2sql&topic=String_Types)

with this line: FieldByName('Data').AsString := vJsonObject.ToJSON;

This save fine the JSON to the Clob field. (IOW, I can see the JSON text from the DB)

Now the problem is when i try to load it ...

var vStream: TMemoryStream; FJsonObject: TJsonObject; begin vStream := TMemoryStream.Create; FJsonObject := TJsonObject.Create;

//btw, this doesn't work -> FSuperObject.Parse(FExaminationQuery.FieldByName('Data').AsString);

TBlobField(FExaminationQuery.FieldByName('Data')).SaveToStream(vStream); vStream.Position := 0;

FJsonObject.LoadFromStream(vStream);

throughs the below error:

Expected "," but found value procedure TJsonReader.AcceptFailed(TokenKind: TJsonTokenKind);

now, if i save the clob data into a file, from notepad++ i can read it but it has not character encoding checked on the notepad++. If i set it to UTF8, save the file and load it from JsonObject it parse it correctly !!!

So i the problem was the encoding !!!

Load/Parse it as Unicode encoding solved the problem: FJsonObject.LoadFromStream(vStream, TEncoding.Unicode); IOW, it parse it from the Database correctly.

So, the LoadFromStream detects a Unicode text incorrectly as UTF8 or i must set it my self ?

Thank you for your help !!

In case you wanted I saved the Json into a file -> http://we.tl/U9KEti4soc

vStream := TMemoryStream.Create; vStream.LoadFromFile('c:\test\test.json'); vStream.Position := 0;

FJsonObject.LoadFromStream(vStream); // fails FJsonObject.LoadFromStream(vStream, TEncoding.Unicode); //works

[ahausladen]

procedure LoadFromStream(Stream: TStream; Encoding: TEncoding = nil; Utf8WithoutBOM: Boolean = True);

If no encoding is specified it assumes UTF-8 (Utf8WithoutBOM=True) or ANSI (Utf8WithoutBOM=False). There is no way to identify UTF-16 without a BOM. So you have to tell JsonDataObject that your stream is TEncoding.Unicode.

[chmichael]

Got it :) Thank you a lot !!