Read Text file stored in a SD card and store it as a string and parse it

Projects Programming
1

Hi guys, I have a big IOT project in which i am using MKR 1000. Currently I want to read JSON objects from my text file stored in a SD card. After receiving the file I need to store it as a string and then eventually parse it.

The Text file(rough) will be in this format

{
"id": 1,
"name": "Leanne Graham",
"username": "Bret",
"email": "Sincere@april.biz",
"address": {
"street": "Kulas Light",
"suite": "Apt. 556",
"city": "Gwenborough",
"zipcode": "92998-3874",
"geo": {
"lat": "-37.3159",
"lng": "81.1496"
}
},
"phone": "1-770-736-8031 x56442",
"website": "hildegard.org",
"company": {
"name": "Romaguera-Crona",
"catchPhrase": "Multi-layered client-server neural-net",
"bs": "harness real-time e-markets"
}
}

I found a code in the SD card library of arduino that shows how to read the file from the SD card. The part I am struggling with is storing it in a string and parsing it. Could someone be kind enough to help me with this problem.

Below is the code that i found online:

/*
SD card read/write

This example shows how to read and write data to and from an SD card file
The circuit:

  • SD card attached to SPI bus as follows:
    ** MOSI - pin 11
    ** MISO - pin 12
    ** CLK - pin 13
    ** CS - pin 4 (for MKRZero SD: SDCARD_SS_PIN)

created Nov 2010
by David A. Mellis
modified 9 Apr 2012
by Tom Igoe

This example code is in the public domain.

*/

#include <SPI.h>
#include <SD.h>

File myFile;

void setup() {
// Open serial communications and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}

Serial.print("Initializing SD card...");

if (!SD.begin(4)) {
Serial.println("initialization failed!");
return;
}
Serial.println("initialization done.");

// open the file. note that only one file can be open at a time,
// so you have to close this one before opening another.
myFile = SD.open("test.txt", FILE_WRITE);

// if the file opened okay, write to it:
if (myFile) {
Serial.print("Writing to test.txt...");
myFile.println("testing 1, 2, 3.");
// close the file:
myFile.close();
Serial.println("done.");
} else {
// if the file didn't open, print an error:
Serial.println("error opening test.txt");
}

// re-open the file for reading:
myFile = SD.open("test.txt");
if (myFile) {
Serial.println("test.txt:");

// read from the file until there's nothing else in it:
while (myFile.available()) {
Serial.write(myFile.read());
}
// close the file:
myFile.close();
} else {
// if the file didn't open, print an error:
Serial.println("error opening test.txt");
}
}

void loop() {
// nothing happens after setup
}