Parse multiple Json

kDohmen

Hello,

I have the same question as in this thread. But I think it is not an option to count the {}brackets.
At the moment I do something like this:

QByteArray json_data;
QJsonDocument doc(QJsonDocument::fromJson(json_data));
json_data.remove(0, doc.toJson().length());

The problem here is that I don't know the format of the incoming Json. This I try to evaluate with:
json_data.startsWith("{\"");

This way is not very good and I hope there is a bettery way to accomplish to parse multiple jsons.

mcosta

Hi,

in the thread you posted the example text is not a valid JSON.
What is the source of these data?

BTW, your solution should work

QByteArray json_data;
QList<QJSonDocument> docs;

while(!json_data.isEmpty()) {
  QJsonDocument doc(QJsonDocument::fromJson(json_data));
  json_data.remove(0, doc.toJson().length());
  docs.push_back(doc);
}

kDohmen

an other application sends me the data via a tcpconntection. but this application sends many json at one time. when I use QTcpSocket.readAll() I get one long string with many Jsons. so I need a way to devorce this string in many little jsons.

mcosta

Hi,

usually in TCP is a best practice to do one of the following:

Send a header with some sync info (special values, length, ...)
Using New-line for text information

Are you sure there's no special character between JSON objects?
Keep in mind that

 QJsonDocument doc(QJsonDocument::fromJson(json_data));
 json_data.remove(0, doc.toJson().length());

could not work because QJsonDocument, make some formatting on the string so doc.toJSon().length() could return a value that is not the same you read.