ESP32 HTTPClient Library – headerName

/*
 * Author: Avant Maker
 * Date: February 24, 2025
 * Version: 1.0
 * Description: This example code demonstrates how to 
 * use the ESP32 HTTPClient Library's headerName method to print 
 * the names of all collected headers to the Serial Monitor.
 * Note: To use this method effectively, you must first 
 * call collectHeaders to specify which headers to capture
 * before making the HTTP request.
 * License: MIT 
 * 
 * Code Source: This example code is sourced from the Comprehensive 
 * Guide to the ESP32 Arduino Core Library, accessible on 
 * AvantMaker.com. For additional code examples and in-depth 
 * documentation related to the ESP32 Arduino Core Library, 
 * please visit:
 *
 * https://avantmaker.com/references/esp32-arduino-core-index/
 *
 * AvantMaker.com, your premier destination for all things 
 * DIY, AI, IoT, Smart Home, and STEM projects. We are dedicated 
 * to empowering makers, learners, and enthusiasts with the resources
 * they need to bring their innovative ideas to life.
 */

#include <WiFi.h>
#include <HTTPClient.h>

const char* ssid = "your-SSID";        // Replace with your Wi-Fi SSID
const char* password = "your-PASSWORD"; // Replace with your Wi-Fi password

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

    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println("\nConnected to Wi-Fi!");
}

void loop() {
    if (WiFi.status() == WL_CONNECTED) {
        HTTPClient http;

        // Define headers to collect
        const char* headerKeys[] = {"Content-Type", "Server"};
        const size_t headerKeysCount = 2;

        // Configure HTTPClient to collect headers
        http.collectHeaders(headerKeys, headerKeysCount);

        // Start the HTTP request
        http.begin("http://www.httpbin.org/get");
        int httpCode = http.GET();

        if (httpCode > 0) {
            // Request successful, retrieve and print header names
            Serial.printf("HTTP Response Code: %d\n", httpCode);
            int headerCount = http.headers(); // Get the number of collected headers
            Serial.printf("Number of headers collected: %d\n", headerCount);

            for (int i = 0; i < headerCount; i++) {
                String headerNameStr = http.headerName(i);
                String headerValue = http.header(i);
                Serial.printf("Header %d - Name: %s, Value: %s\n", i, headerNameStr.c_str(), headerValue.c_str());
            }
        } else {
            Serial.println("Error on HTTP request");
        }

        http.end(); // Free resources
    }

    delay(10000); // Wait 10 seconds before the next request
}