为RC模型制作遥测模块，尝试获取HTTP响应时，都会收到类似“无效的http协议”是为何？

我为 RC 模型制作了自己的遥测模块，但我在 PC 上开发客户端软件时遇到了问题。我尝试用 C# 和 Java 来做，但在这两种情况下，当我尝试获取 HTTP 响应时，我都会收到类似“无效的 http 协议”或类似的错误。所以我认为我的 ESP8266 配置有问题。
在浏览器中它以良好的方式显示，但在 Java 或 C# 中它不起作用。
我的ESP固件是：
AT+GMR
0018000902-AI03
可以看看吗？
代码：全选#include  
#include
#include

Adafruit_BMP085 sensorBMP180;
SoftwareSerial esp(8,9);

float tempC;
float pressure;
float altitude;
float initAltitude;
float realAltitude;
byte responseCode;

void setup(){
Serial.begin(38400); //turn on serial monitor
esp.begin(38400);

sendCommand("AT+RST\r\n",2000); // reset module
sendCommand("AT+CWMODE=2\r\n",1000); // configure as access point  
sendCommand("AT+CIFSR\r\n",1000); // get ip address
sendCommand("AT+CIPMUX=1\r\n",1000); // configure for multiple connections
sendCommand("AT+CIPSERVER=1,80\r\n",1000); // turn on server on port 80
  
sensorBMP180.begin();   //initialize
initAltitude = sensorBMP180.readAltitude();
}

void loop() {
tempC = sensorBMP180.readTemperature();
pressure = sensorBMP180.readPressure();
altitude = sensorBMP180.readAltitude();
realAltitude = altitude - initAltitude;

if(esp.available()){
   
    if(esp.find("+IPD,")){
     delay(2000);

     int connectionId = esp.read()-48;
     
     String dataToSend = "\n";
     dataToSend += "\n";
     String sVar = String(tempC);

     dataToSend += sVar;
     dataToSend += "\n";

     dataToSend += "";
     sVar = String(pressure/100);
     dataToSend += sVar;
     dataToSend += "\n";

     dataToSend+="";
     sVar = String(altitude);
     dataToSend += sVar;
     dataToSend += "\n";

     dataToSend+="";
     sVar = String(realAltitude);
     dataToSend += sVar;
     dataToSend += "\n";
     
     String cmdCIPSEND = "AT+CIPSEND=";
     cmdCIPSEND += connectionId;
     cmdCIPSEND += ",";
     cmdCIPSEND +=dataToSend.length();
     cmdCIPSEND +="\r\n";
   
     sendCommand(cmdCIPSEND,2000);
     sendCommand(dataToSend,2000);

     String closeCommand = "AT+CIPCLOSE=";
     closeCommand+=connectionId;
     closeCommand+="\r\n";
     
     sendCommand(closeCommand,3000);
     }
  }
}

String sendCommand(String command, const int timeout){
    String response = "";
   
    esp.print(command);
   
    long int time = millis();
   
    while( (time+timeout) > millis()){
      while(esp.available()){
        char c = esp.read();
        response+=c;
      }  
    }
   Serial.print(response);   
    return response;
}