我已經(jīng)在spring boot應(yīng)用程序中創(chuàng)建了api。我的arduino代碼在arduino日志中返回-1（httpcode）。因此，我的api用于發(fā)布數(shù)據(jù)的方法是http：// localhost：8080 / ApparelProject / device / saveDistance / {value}，以下是我的arduino代碼。arduino代碼#include <ESP8266HTTPClient.h>#include <ESP8266WiFi.h> // defines pins numbersconst int trigPin = 2;  //D4const int echoPin = 0;  //D3// defines variableslong duration;int distance;void setup() {pinMode(trigPin, OUTPUT); // Sets the trigPin as an OutputpinMode(echoPin, INPUT); // Sets the echoPin as an InputSerial.begin(9600); // Starts the serial communication}void loop() {// Clears the trigPindigitalWrite(trigPin, LOW);delayMicroseconds(2);// Sets the trigPin on HIGH state for 10 micro secondsdigitalWrite(trigPin, HIGH);delayMicroseconds(10);digitalWrite(trigPin, LOW);// Reads the echoPin, returns the sound wave travel time in microsecondsduration = pulseIn(echoPin, HIGH);// Calculating the distancedistance= duration*0.034/2;// Prints the distance on the Serial MonitorSerial.print("Distance: ");Serial.println(distance);   HTTPClient http;    http.begin("http://localhost:8080/ApparelProject/device/saveDistance");    http.addHeader("Content-Type", "text/plain;charset=UTF-8");  int httpCode = http.POST("125");    Serial.println(httpCode);       http.end();   /* HTTPClient http;       String url = "localhost:8080/ApparelProject/device/saveDistance/"+String(distance);       Serial.println(url);       //localhost:8080/ApparelProject/device/saveDistance/20000            http.begin(url);        //POST method       int httpCode = http.GET();       Serial.println(httpCode);       http.end();*/delay(2000);}彈簧碼   @RequestMapping(value = "/saveDistance/{distance}", method = RequestMethod.POST)    public String saveDistance(HttpServletRequest request, @PathVariable(value ="distance") String distance) {        System.out.println(distance);        return distanceimpl.saveDistance(distance);    }