This example uses ArduinoJson library to parse json data provided by the server

esp8266_http_json.ino

/*
  This example uses ArduinoJson library to parse json data provided by the server
  Download it and install it from: https://github.com/bblanchon/ArduinoJson
 */


#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <ArduinoJson.h>

const char* ssid = "Your_ssid";
const char* password = "password";


// Upload new values to the webserver
void sendRequestToServer() {
  String url = "http://your_url_goes_here";

  HTTPClient http;
  http.begin(url);
  http.addHeader("Accept", "application/json");

  int httpCode = http.GET();
  Serial.printf("HTTP URL=[%s] code: %d\n", url.c_str(), httpCode);
  if (httpCode == 200) {
    String payload = http.getString();
    Serial.println(payload);

    StaticJsonBuffer<2000> jsonBuffer;
    JsonObject& root = jsonBuffer.parseObject(payload);

    // Your json is parsed and you can use it via the root object
    // For more information, check out the documentation of 
    // ArduinoJson

  }
  else {
    Serial.println("(!) ERROR");
  }
}




void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());

}


void loop() {
  sendRequestToServer();
  delay(5000);
}