例子介绍：
通过TCP client包装Http请求协议去调用天气接口获取天气信息
源码：
/**
* Demo：
* 演示Http请求天气接口信息
* @author 单片机菜鸟
* @date 2019/09/04
*/
#include <ESP8266WiFi.h>
#include <
ArduinoJson.h>
//以下三个定义为调试定义
#define DebugBegin(baud_rate) Serial.begin(baud_rate)
#define DebugPrintln(message) Serial.println(message)
#define DebugPrint(message) Serial.print(message)
const char* ssid
= "TP-LINK_5344";
// XXXXXX -- 使用时请修改为当前你的 wifi ssid
const char* password = "6206908you11011010";
// XXXXXX -- 使用时请修改为当前你的 wifi 密码
const char* host = "api.seniverse.com";
const char* APIKEY = "wcmquevztdy1jpca";
//API KEY
const char* city = "guangzhou";
const char* language = "zh-Hans";//zh-Hans 简体中文 会显示乱码
const unsigned long BAUD_RATE = 115200;
// serial connection speed
const unsigned long HTTP_TIMEOUT = 5000;
// max respone time from server
const size_t MAX_CONTENT_SIZE = 1000;
// max size of the HTTP response
// 我们要从此网页中提取的数据的类型
struct WeatherData {
char city[16];//城市名称
char weather[32];//天气介绍（多云...）
char temp[16];//温度
char udate[32];//更新时间
};
WiFiClient client;
char response[MAX_CONTENT_SIZE];
char endOfHeaders[] = "\r\n\r\n";
void setup() {
// put your setup code here, to run once:
WiFi.mode(WIFI_STA);
//设置esp8266 工作模式
DebugBegin(BAUD_RATE);
DebugPrint("Connecting to ");//写几句提示，哈哈
DebugPrintln(ssid);
WiFi.begin(ssid, password); //连接wifi
WiFi.setAutoConnect(true);
while (WiFi.status() != WL_CONNECTED) {
//这个函数是wifi连接状态，返回wifi链接状态
delay(500);
DebugPrint(".");
}
DebugPrintln("");
DebugPrintln("WiFi connected");
delay(500);
DebugPrintln("IP address: ");
DebugPrintln(WiFi.localIP());//WiFi.localIP()返回8266获得的ip地址
client.setTimeout(HTTP_TIMEOUT);
}
void loop() {
// put your main code here, to run repeatedly:
//判断tcp client是否处于连接状态，不是就建立连接
while (!client.connected()){
if (!client.connect(host, 80)){
DebugPrintln("connection....");
delay(500);
}
}
//发送http请求 并且跳过响应头 直接获取响应body
if (sendRequest(host, city, APIKEY) && skipResponseHeaders()) {
//清除缓冲
clrEsp8266ResponseBuffer();
//读取响应数据
readReponseContent(response, sizeof(response));
WeatherData weatherData;
if (parseUserData(response, &weatherData)) {
printUserData(&weatherData);
}
}
delay(5000);//每5s调用一次
}
/**
* @发送http请求指令
*/
bool sendRequest(const char* host, const char* cityid, const char* apiKey) {
// We now create a URI for the request
//心知天气 发送http请求
String GetUrl = "/v3/weather/now.json?key=";
GetUrl += apiKey;
GetUrl += "&location=";
GetUrl += city;
GetUrl += "&language=";
GetUrl += language;
// This will send the request to the server
client.print(String("GET ") + GetUrl + " HTTP/1.1\r\n" +
"Host: " + host + "\r\n" +
"Connection: close\r\n\r\n");
DebugPrintln("create a request:");
DebugPrintln(String("GET ") + GetUrl + " HTTP/1.1\r\n" +
"Host: " + host + "\r\n" +
"Connection: close\r\n");
delay(1000);
return true;
}
/**
* @Desc 跳过 HTTP 头，使我们在响应正文的开头
*/
bool skipResponseHeaders() {
// HTTP headers end with an empty line
bool ok = client.find(endOfHeaders);
if (!ok) {
DebugPrintln("No response or invalid response!");
}
return ok;
}
/**
* @Desc 从HTTP服务器响应中读取正文
*/
void readReponseContent(char* content, size_t maxSize) {
size_t length = client.peekBytes(content, maxSize);
delay(100);
DebugPrintln("Get the data from Internet!");
content[length] = 0;
DebugPrintln(content);
DebugPrintln("Read data Over!");
client.flush();//清除一下缓冲
}
/**
* @Desc 解析数据 Json解析
* 数据格式如下：
* {
* "results": [
*
{
*
"location": {
*
"id": "WX4FBXXFKE4F",
*
"name": "北京",
*
"country": "CN",
*
"path": "北京,北京,中国",
*
"timezone": "Asia/Shanghai",
*
"timezone_offset": "+08:00"
*
},
*
"now": {
*
"text": "多云",
*
"code": "4",
*
"temperature": "23"
*
},
*
"last_update": "2017-09-13T09:51:00+08:00"
*
}
* ]
*}
*/
bool parseUserData(char* content, struct WeatherData* weatherData) {
// -- 根据我们需要解析的数据来计算JSON缓冲区最佳大小
// 如果你使用StaticJsonBuffer时才需要
// const size_t BUFFER_SIZE = 1024;
// 在堆栈上分配一个临时内存池
// StaticJsonBuffer<BUFFER_SIZE> jsonBuffer;
// -- 如果堆栈的内存池太大，使用 DynamicJsonBuffer jsonBuffer 代替
DynamicJsonBuffer jsonBuffer;
JsonObject& root = jsonBuffer.parseObject(content);
if (!root.success()) {
DebugPrintln("JSON parsing failed!");
return false;
}
//复制我们感兴趣的字符串
strcpy(weatherData->city, root["results"][0]["location"]["name"]);
strcpy(weatherData->weather, root["results"][0]["now"]["text"]);
strcpy(weatherData->temp, root["results"][0]["now"]["temperature"]);
strcpy(weatherData->udate, root["results"][0]["last_update"]);
// -- 这不是强制复制，你可以使用指针，因为他们是指向“内容”缓冲区内，所以你需要确保
// 当你读取字符串时它仍在内存中
return true;
}
// 打印从JSON中提取的数据
void printUserData(const struct WeatherData* weatherData) {
DebugPrintln("Print parsed data :");
DebugPrint("City : ");
DebugPrint(weatherData->city);
DebugPrint(", \t");
DebugPrint("Weather : ");
DebugPrint(weatherData->weather);
DebugPrint(",\t");
DebugPrint("Temp : ");
DebugPrint(weatherData->temp);
DebugPrint(" C");
DebugPrint(",\t");
DebugPrint("Last Updata : ");
DebugPrint(weatherData->udate);
DebugPrintln("\r\n");
}
// 关闭与HTTP服务器连接
void stopConnect() {
DebugPrintln("Disconnect");
client.stop();
}
void clrEsp8266ResponseBuffer(void){
memset(response, 0, MAX_CONTENT_SIZE);
//清空
}
注意点：
