file_get_contents 不在 POST 请求中发送数据内容

Question

我正在尝试从网页调用的 PHP 脚本向 arduino 发送 POST 请求。我正在使用 file_get_contents() 来完成这个。我在这里阅读了 PHP 手册中的示例：Here。看起来 Arduino 正在接收 POST 请求，但数据流中没有包含任何内容，只有 headers 和内容参数。这是我的相关 php

        // send database updates to the arduino
        $url = 'http://'.$ip;
        $options = array(
            'http' => array(
                'header' => "Content-type: application/x-www/form-urlencoded\r\n",
                'method' => 'POST',
                'content' => http_build_query($responseText)
            ),
        );
        
        $context = stream_context_create($options);
        $result = file_get_contents($url, false, $context);

目前在 Arduino 上，我只是将整个 POST 请求转储到终端，以便我可以验证它是否已被接收。这是 Arduino 终端的输出。

Ethernet WebServer Example
server is at 192.168.3.3
new client
POST / HTTP/1.0
Host: 192.168.3.3
Connection: close
Content-Length: 80
Content-type: application/x-www/form-urlencoded

client disconnected

如您所见，整个 POST 请求都在那里接受内容。它显示 Content-Length 但没有实际内容。

这是生成终端输出的 Arduino 代码。无非就是Arduino自带的Web Server例子IDE.

/*
  Web Server

 A simple web server that shows the value of the analog input pins.
 using an Arduino Wiznet Ethernet shield.

 Circuit:
 * Ethernet shield attached to pins 10, 11, 12, 13
 * Analog inputs attached to pins A0 through A5 (optional)

 created 18 Dec 2009
 by David A. Mellis
 modified 9 Apr 2012
 by Tom Igoe
 modified 02 Sept 2015
 by Arturo Guadalupi
 
 */

#include <SPI.h>
#include <Ethernet.h>

// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
IPAddress ip(192, 168, 3, 3);

// Initialize the Ethernet server library
// with the IP address and port you want to use
// (port 80 is default for HTTP):
EthernetServer server(80);

String postData;

void setup() {
  // You can use Ethernet.init(pin) to configure the CS pin
  Ethernet.init(10);  // Most Arduino shields
  //Ethernet.init(5);   // MKR ETH shield
  //Ethernet.init(0);   // Teensy 2.0
  //Ethernet.init(20);  // Teensy++ 2.0
  //Ethernet.init(15);  // ESP8266 with Adafruit Featherwing Ethernet
  //Ethernet.init(33);  // ESP32 with Adafruit Featherwing Ethernet

  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }
  Serial.println("Ethernet WebServer Example");

  // start the Ethernet connection and the server:
  Ethernet.begin(mac, ip);

  // Check for Ethernet hardware present
  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
    Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
    while (true) {
      delay(1); // do nothing, no point running without Ethernet hardware
    }
  }
  if (Ethernet.linkStatus() == LinkOFF) {
    Serial.println("Ethernet cable is not connected.");
  }

  // start the server
  server.begin();
  Serial.print("server is at ");
  Serial.println(Ethernet.localIP());
}


void loop() {
  // listen for incoming clients
  EthernetClient client = server.available();
  if (client) {
    Serial.println("new client");
    // an http request ends with a blank line
    boolean currentLineIsBlank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        //postData = postData + c;
        Serial.write(c);
        // if you've gotten to the end of the line (received a newline
        // character) and the line is blank, the http request has ended,
        // so you can send a reply
        if (c == '\n' && currentLineIsBlank) {
          // send a standard http response header
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");
          client.println("Connection: close");  // the connection will be closed after completion of the response
          //client.println("Refresh: 5");  // refresh the page automatically every 5 sec
          client.println();
          /*client.println("<!DOCTYPE HTML>");
          client.println("<html>");
          // output the value of each analog input pin
          for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
            int sensorReading = analogRead(analogChannel);
            client.print("analog input ");
            client.print(analogChannel);
            client.print(" is ");
            client.print(sensorReading);
            client.println("<br />");
          }
          client.println("</html>");*/
          break;
        }
        if (c == '\n') {
          // you're starting a new line
          currentLineIsBlank = true;
        } else if (c != '\r') {
          // you've gotten a character on the current line
          currentLineIsBlank = false;
        }
      }
    }
    // give the web browser time to receive the data
    delay(1);
    Serial.println("client disconnected");
  }
}

什么原因导致 POST 请求的内容无法从 PHP 发送？

Answer 1

让我的大脑休息了大约半天后，我确定了问题的原因。它根本不在 PHP 中。这是由 Arduino 代码中的这个 IF 块引起的

if (c == '\n' && currentLineIsBlank) {
    // send a standard http response header
    client.println("HTTP/1.1 200 OK");
    client.println("Content-Type: text/html");
    client.println("Connection: close");
    //client.println("Refresh: 5");
    client.println();
    /*client.println("<!DOCTYPE HTML>");
    client.println("<html>");
    // output the value of each analog input pin
    for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
        int sensorReading = analogRead(analogChannel);
        client.print("analog input ");
        client.print(analogChannel);
        client.print(" is ");
        client.print(sensorReading);
        client.println("<br />");
    }
    client.println("</html>");*/
    break;
}

它导致它嵌套的 while 循环在 header 和内容之间的空行处终止。我的 Arduino 新工作代码是

#include <SPI.h>
#include <Ethernet.h>

// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
IPAddress ip(192, 168, 3, 3);

// Initialize the Ethernet server library
// with the IP address and port you want to use
// (port 80 is default for HTTP):
EthernetServer server(80);

String postData;

void setup() {
  // You can use Ethernet.init(pin) to configure the CS pin
  Ethernet.init(10);  // Most Arduino shields
  
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }
  Serial.println("Ethernet WebServer Example");

  // start the Ethernet connection and the server:
  Ethernet.begin(mac, ip);

  // Check for Ethernet hardware present
  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
    Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
    while (true) {
      delay(1); // do nothing, no point running without Ethernet hardware
    }
  }
  if (Ethernet.linkStatus() == LinkOFF) {
    Serial.println("Ethernet cable is not connected.");
  }

  // start the server
  server.begin();
  Serial.print("server is at ");
  Serial.println(Ethernet.localIP());
}


void loop() {
  // listen for incoming clients
  EthernetClient client = server.available();
  if (client) {
    Serial.println("new client");
    
    while (client.connected()) {
      while (client.available()) {
        char c = client.read();
        postData = postData + c;
        // send a standard http response header
        client.println("HTTP/1.1 200 OK");
        client.println("Content-Type: text/html");
        client.println("Connection: close");
        client.println();
      }
      client.stop();
    }
    // give the web browser time to receive the data
    delay(1);
    
    Serial.println("\r\nclient disconnected");
    Serial.println(postData);
    Serial.println(postData.substring(postData.indexOf("status=")+7, postData.indexOf("status=")+8 ));
  }
}

file_get_contents 不在 POST 请求中发送数据内容

file_get_contents does not send data content in a POST request

php

arduino