Key and value is present but returns NULL

[vaz83]

Hi,
I am facing a strange problem. I saved a JSON document into the ESP8266 file system.

Then i load it using this code:
` DynamicJsonDocument jDocLoad(1500);
DynamicJsonDocument jDoc(1500);

if (LittleFS.begin())
{
if (LittleFS.exists("/topRecordings.json"))
{
File cFile = LittleFS.open("/topRecordings.json", "r");
if (cFile)
{
size_t size = cFile.size();
// Allocate a buffer to store contents of the file.
std::unique_ptr<char[]> buf(new char[size]);
cFile.readBytes(buf.get(), size);
DeserializationError err = deserializeJson(jDocLoad,buf.get());
Serial.println(err.c_str());
serializeJsonPretty(jDocLoad,Serial);
}
cFile.close();
}`

The output of the serializeJsonPretty is this:

{
"maxTempC": 26.54,
"maxTempF": 79.772,
"maxTempTimeStampUTC": "2020-05-19T15:51:44",
"maxTempUNIXTime": 1589903504
}

After, i try to get the maxTempC value, but gives no value and when i put the line jDocLoad.containsKey("maxTempC") it returns FALSE, while the key and value is there which can be seen on the serializeJSonPretty.

What can be the problem?

[ewaldc]

You can deserialize directly from a stream:
DeserializationError err = deserializeJson(jDocLoad, cFile);
Less lines of code and less memory used...

What is your problem exactly ? If serializeJsonPretty returns the correct Json, than it means you have no error from deserializeJson and thus all is read fine from LittleFS. In that case, the problem is not in the code above. Or do I understand this wrong?

[vaz83]

It returns the correct code, but right after i do this:

jDocLoad.containsKey("maxTempC") which returns false.. it's only the first field, i don't understand why..

[vaz83]

Deserialize directly from the stream solved the problem! :) thanks