POST request on esp8266 raw input/json with Arduino IDE - json

Question

I am trying to send post request with esp8266 programmed on arduino IDE, but there's lack of examples how to do it. I would like to send request to json server with raw input so it would look like this:
http://ip:port/something
BODY
{
"valuename":value
}
Would be grateful if anyone could show me such an example.
Greetings

Answer 1

For handling HTTP requests, you can use a RestClient library rather than writing all the low level requests. It saves a lot of time and is less error-prone.
For example, for a GET request, all you have to do is:
String response = "";
int statusCode = client.post("/", "foo=bar", &response);
One good such library with SSL support is written by github user DaKaz.
You can use it for your GET request. The returned response will be without the HTTP header. The function will return the response from the server without the headers.
Now you can use the ArduinoJson Library by bblanchin for decoding the JSON object.
Details can be seen here.
Or you can do plain string manipuation to get the values though it is not a recommended route to take and is prone to errors.

Answer 2

Here is an example to send JSON via HTTP library :
#include <ESP8266WiFi.h>
#include <ArduinoJson.h>
#include <ArduinoHttpClient.h>
#define JSON_BUF_SIZE 256
WiFiClient wifi;
HttpClient poster = HttpClient(wifi, IP, PORT);
void HTTPPost(){
String contentType = "application/json";
StaticJsonBuffer<JSON_BUF_SIZE> jsonBuffer;
JsonObject& jsonData = jsonBuffer.createObject();
jsonData["valuename"] = "value";
String postData = "";
jsonData.printTo(postData);
poster.post("/", contentType, postData);
printf("Trace : ResponseCode : %d\n", poster.responseStatusCode());
printf("Trace : Incoming Body : %s\n", poster.responseBody().c_str());
}