如何从http请求ESP32中获取所用时间

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

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

void setup() {
  Serial.begin(115200);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // 发送HTTP请求并获取所用时间
  long startTime = millis();

  HTTPClient http;
  http.begin("http://example.com");  // 替换为目标服务器的URL
  int httpResponseCode = http.GET();
  if (httpResponseCode > 0) {
    Serial.print("HTTP Response code: ");
    Serial.println(httpResponseCode);
  } else {
    Serial.print("Error code: ");
    Serial.println(httpResponseCode);
  }
  http.end();

  long endTime = millis();
  long elapsedTime = endTime - startTime;
  Serial.print("HTTP request took ");
  Serial.print(elapsedTime);
  Serial.println(" milliseconds");
}

void loop() {
  // 无需在循环中执行任何操作
}