求助：实现以太网设备通过RESTful API(JSON)请求数据并向指定IP发送字符串

Great question—this is a classic middleware scenario, and totally doable with either off-the-shelf tools or a small custom script running on a low-cost device. Let’s walk through your options and the key steps to make this work:

Your middleware device needs to handle two main tasks:

1. Pull data from your security controller via its RESTful JSON API
2. Transform & push the required string to your video monitoring software’s target IP

Since everything’s on the same LAN, network connectivity should be straightforward—no public internet routing needed.

Option 1: Python Script (Fastest, Most Flexible) #

Python is perfect for this kind of lightweight data handling. You can run this on a cheap device like a Raspberry Pi (even a Zero W, which is tiny and low-power), or even an old laptop/desktop if you have one spare.

Step-by-Step Setup #

• Install dependencies: Use pip install requests to handle the API calls, and Python’s built-in socket module for sending raw strings (if the monitoring software expects TCP/UDP).
• Write the core logic:
  1. Poll the controller’s REST API at regular intervals (use time.sleep() for simple scheduling, or APScheduler for more advanced cron-style timing).
  2. Parse the JSON response to extract the data you need to build the required string.
  3. Send the formatted string to the monitoring software’s IP/port.

Example Code Snippet #

import requests
import socket
import time

# Configuration
CONTROLLER_API_URL = "http://192.168.1.100/api/data"  # Replace with your controller's API endpoint
MONITORING_IP = "192.168.1.200"
MONITORING_PORT = 1234  # Replace with your monitoring software's target port
POLL_INTERVAL = 5  # Check controller every 5 seconds

def get_controller_data():
    try:
        response = requests.get(CONTROLLER_API_URL)
        response.raise_for_status()  # Raise error if API call fails
        return response.json()
    except requests.exceptions.RequestException as e:
        print(f"Failed to fetch data from controller: {e}")
        return None

def send_string_to_monitor(data):
    # Transform JSON data to your required string format
    # Example: If JSON has {"event": "motion", "zone": 3}, build "MOTION_ZONE_3"
    formatted_string = f"MOTION_ZONE_{data['zone']}" if data.get('event') == 'motion' else "NO_EVENT"
    
    # Send via TCP (adjust for UDP if needed)
    try:
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
            s.connect((MONITORING_IP, MONITORING_PORT))
            s.sendall(formatted_string.encode('utf-8'))
            print(f"Sent string: {formatted_string}")
    except socket.error as e:
        print(f"Failed to send data to monitoring software: {e}")

if __name__ == "__main__":
    while True:
        controller_data = get_controller_data()
        if controller_data:
            send_string_to_monitor(controller_data)
        time.sleep(POLL_INTERVAL)

Option 2: Node.js Script #

If you prefer JavaScript, Node.js works just as well. Use axios for API calls and the built-in net module for socket communication. The logic will mirror the Python example—poll, parse, send.

Option 3: Embedded Device (ESP32/ESP8266) #

If you want a dedicated, ultra-low-power hardware solution, an ESP32 (which has built-in WiFi and enough processing power for REST calls) is ideal. You can program it using Arduino IDE or MicroPython. This is great if you don’t want to rely on a full computer.

• Network Reachability: Ensure all devices are on the same subnet, and no LAN firewalls are blocking traffic between the middleware device, controller, and monitoring software. Test connectivity with ping and telnet (e.g., telnet 192.168.1.200 1234) to confirm the monitoring port is open.
• Error Handling: Add retries for failed API calls or socket connections, and log errors to a file or console so you can troubleshoot issues.
• Trigger vs. Polling: If your controller supports webhooks (sending data when an event occurs instead of waiting to be polled), use that instead of regular polling—it’s more efficient. You’ll just need to set up the middleware device to listen for incoming webhook requests, then forward the string immediately.
• String Format: Double-check the exact string format the monitoring software expects (encoding, delimiters, etc.)—a mismatch here is the most common cause of failed pushes.

内容的提问来源于stack exchange，提问作者Jack Hudgins