Spiffs Json

#include <FS.h>
#include <ArduinoJson.h>
int MyValue1,MyValue2,MyValue3,MyValue4;

bool loadConfiguration()
{
 File file = SPIFFS.open("/config.json", "r");
 if (!file)
 {
  Serial.println("Failed to open config file");
  return false;
 }

  StaticJsonBuffer<512> jsonBuffer;

  // Parse the root object
  JsonObject &root = jsonBuffer.parseObject(file);

  if (!root.success())
    Serial.println(F("Failed to read file, using default configuration"));

  // Copy values from the JsonObject to the Config
 MyValue1 = root["Value1"];
 MyValue2 = root["Value2"];
 MyValue3 = root["Value3"];
 MyValue4 = root["Value4"];

  // Close the file (File's destructor doesn't close the file)
  file.close();
}

bool saveConfiguration()
{
 File file = SPIFFS.open("/config.json", "w");
 if (!file)
 {
  Serial.println("Failed to open config file for writing");
  return false;
 }

 StaticJsonBuffer<256> jsonBuffer;

 // Parse the root object
 JsonObject &root = jsonBuffer.createObject();

 // Set the values
 root["Value1"] = MyValue1;
 root["Value2"] = MyValue2;
 root["Value3"] = MyValue3;
 root["Value4"] = MyValue4;

 // Serialize JSON to file
 if (root.printTo(file) == 0)
 {
  Serial.println(F("Failed to write to file"));
 }
 file.close();
}

void setup()
{
 Serial.begin(115200);
 MyValue1 = random(1,99);
 MyValue2 = random(1,99);
 MyValue3 = random(1,99);
 MyValue4 = random(1,99);

 Serial.println("\n\nMounting FS...\n");
 if (!SPIFFS.begin())
 {
  Serial.println("erreur SPIFFS");
  while (true); // on ne va pas plus loin
 }

 if(!saveConfiguration)
  { Serial.println(F("failed to Save...")); }
 else
 { Serial.println(F("Saved OK...")); }

 if(!loadConfiguration)
  { Serial.println(F("Failed to load...")); }
 else
 { Serial.println(F("Load OK...")); }
}

______________________________________________________________________________________________________________
***************************************
Code Example Using JSON
https://github.com/tzapu/WiFiManager/blob/master/examples/AutoConnectWithFSParametersAndCustomIP/AutoConnectWithFSParametersAndCustomIP.ino#L7
*****************************************
#include <FS.h>
#include <ArduinoJson.h>

int MyValue1,MyValue2,MyValue3,MyValue4;

//Save parameters to JSON file
void saveConfiguration()
{
 if (SPIFFS.exists("/config.json"))
 {
  //file exists, Saving configuration
  Serial.println("saving config");
  DynamicJsonBuffer jsonBuffer;
  JsonObject& json = jsonBuffer.createObject();
  //json["mqtt_server"] = mqtt_server;
  //json["mqtt_port"] = mqtt_port;
  //json["blynk_token"] = blynk_token;
  json["MyValue1"] = MyValue1;
  json["MyValue2"] = MyValue2;
  json["MyValue3"] = MyValue3;
  json["MyValue4"] = MyValue4;

  File configFile = SPIFFS.open("/config.json", "w");
  if (!configFile) { Serial.println("failed to open config file for writing"); }
  json.prettyPrintTo(Serial);
  json.printTo(configFile);

  if (json.printTo(configFile) == 0)
   { Serial.println(F("Failed to write to file")); }
  configFile.close();
  //end save
 }
 else{ Serial.println("The JSON file doesn't exist "); }
}

//Load parameters from JSON file
void loadConfiguration()
{
 if (SPIFFS.exists("/config.json"))
 {
  //file exists, reading and loading
  Serial.println("reading config file");
  File configFile = SPIFFS.open("/config.json", "r");
  if (configFile)
  {
   Serial.println("opened config file");
   size_t size = configFile.size();
   // Allocate a buffer to store contents of the file.
   std::unique_ptr<char[]> buf(new char[size]);

   configFile.readBytes(buf.get(), size);
   DynamicJsonBuffer jsonBuffer;
   JsonObject& json = jsonBuffer.parseObject(buf.get());
   json.printTo(Serial);

   if (json.success())
   {
    //strcpy(mqtt_server, json["mqtt_server"]); // char string_c
    //static_ip = json["ip"];
    MyValue1 = json["MyValue1"];
    MyValue2 = json["MyValue2"];
    MyValue3 = json["MyValue3"];
    MyValue4 = json["MyValue4"];
    //strcpy(MyValue1, json["MyValue1"]); // char string_c
    //static_gw = json["gateway"];
    /*Serial.println("converting ip");
    IPAddress ip = ipFromCharArray(static_ip);
    Serial.println(ip);*/
    //MyValue1 = ipFromCharArray(MyValue1);
   }
   else{ Serial.println("failed to load json config"); }
  }
  else{ Serial.println("Failed to open config file"); }
  configFile.close();
  Serial.print("MyValue1 :");Serial.println(MyValue1);
  Serial.print("MyValue2: ");Serial.println(MyValue2);
  Serial.print("MyValue3: ");Serial.println(MyValue3);
  Serial.print("MyValue4: ");Serial.println(MyValue4);
 }
 else{ Serial.println("The JSON file doesn't exist "); }
}

void setup()
{
 // put your setup code here, to run once:
 Serial.begin(115200);
 Serial.println();
 //read configuration from FS json
 Serial.println("mounting FS...");

 if (SPIFFS.begin())
  { Serial.println("mounted file system"); }
 else { Serial.println("failed to mount FS"); }

 saveConfiguration();
 loadConfiguration();

  //Serial.println("local ip");
  //Serial.println(WiFi.localIP());
  //Serial.println(WiFi.gatewayIP());
  //Serial.println(WiFi.subnetMask());
}

void loop()
{
  // put your main code here, to run repeatedly:
}