AliOS Things 3.0應用筆記：http client簡單應用

簡介

AliOS Things 3.0版本於9月27日在雲棲大會正式發佈，在新版本中帶來了全新的應用開發框架，幫助用戶快速構建自己的應用。使用戶可以更專注於自身應用的開發。
AliOS Things 3.0版本新增加了httpc組件（http 客戶端組件），httpc組件支持多種RESTful的API調用，包括GET、POST、PUT、HEAD等，也支持https安全協議。

準備工作

參考 AliOS Things Environment Setup 和 AliOS Things 3.0 應用開發指南 搭建好AliOS Things 3.0的應用開發環境。

創建應用工程

參考AliOS Things 3.0 應用開發指南 > AliOS Studio中創建應用工程創建好你的應用工程。

本示例新建的應用工程名稱爲httpclient_app，選擇的開發板爲developerkit。

編寫應用代碼

新建好的應用工程文件如下面所示：

.httpclient_app
├── .aos               # AliOS Things 3.0 應用工程描述
├── .vscode            # AliOS Studio 配置文件
├── Config.in          # Menuconfig 配置文件
├── README.md          # 應用說明文檔
├── aos.mk             # 編譯文件
├── app_main.c         # 應用示例代碼
└── k_app_config.h     # 內核配置

添加http組件

aos-cube會自動根據include的頭文件來自動添加組件。

http組件需要用到全局宏：BUILD_AOS，所以需要在aos.mk中額外增加一個全局宏定義：

GLOBAL_DEFINES += BUILD_AOS

天氣API說明

本示例使用http組件，發送http get請求獲取天氣數據，天氣的API是中國天氣網提供的API：http://www.weather.com.cn/data/sk/101210101.html，其中101210101代表是杭州。

使用curl命令可以測試該API接口：

$ curl http://www.weather.com.cn/data/sk/101210101.html
{"weatherinfo":{"city":"杭州","cityid":"101210101","temp":"24.8","WD":"東北風","WS":"小於3級","SD":"81%","AP":"1000.3hPa","njd":"暫無實況","WSE":"<3","time":"17:50","sm":"2.1","isRadar":"1","Radar":"JC_RADAR_AZ9571_JB"}}%

或者也可以在瀏覽器打開該鏈接測試API接口。

使用http組件

本示例主要使用到了http如下接口，詳細的http對外提供的接口和參數說明請參考include/network/http/http.h：

/* httpc 初始化 */
int8_t http_client_initialize(void);

/* 創建一個httpc實例 */
httpc_handle_t httpc_init(httpc_connection_t *settings);

/* 銷燬一個httpc實例 */
int8_t httpc_deinit(httpc_handle_t httpc);

/* 發送http請求 */
int8_t httpc_send_request(httpc_handle_t httpc, int8_t method, char *uri,
                          const char *hdr, const char *content_type,
                          const char *param, uint16_t param_len);

/* 構建http請求header */
int32_t httpc_construct_header(char *buf, uint16_t buf_size, const char *name, const char *data);

/* 等待接口http返回 */
int32_t httpc_recv_response(httpc_handle_t httpc, uint8_t *rsp, uint32_t rsp_size,
                            http_rsp_info_t *info, uint32_t timeout);

完整源碼

aos.mk：

NAME := httpclient_app

$(NAME)_MBINS_TYPE := app
$(NAME)_VERSION := 1.0.0
$(NAME)_SUMMARY := httpclient_app

$(NAME)_SOURCES += app_main.c

GLOBAL_DEFINES += BUILD_AOS

GLOBAL_INCLUDES += ./

$(NAME)_COMPONENTS_CUSTOMIZED := http yloop
$(NAME)_COMPONENTS += $($(NAME)_COMPONENTS_CUSTOMIZED)

app_main.c：

/*
 * Copyright (C) 2015-2017 Alibaba Group Holding Limited
 */

#include <stdio.h>

#include <aos/kernel.h>
#include <aos/yloop.h>
#include <http.h>
#include <network/network.h>

#define WIFI_SSID "aiot"
#define WIFI_PASSWD "12345678"

#define REQ_BUF_SIZE 2048
#define RSP_BUF_SIZE 4096
#define HTTP_UP_HDR_SIZE 128

/* weather api hostname */
#define WEATHER_HOSTNAME "http://www.weather.com.cn/"
/* weather api uri */
#define WEATHER_URI "data/sk/101210101.html"

static httpc_handle_t httpc_handle = 0;
static httpc_connection_t settings;

/* buffer for send & receive */
static uint8_t rsp_buf[RSP_BUF_SIZE] = {0};
static uint8_t req_buf[REQ_BUF_SIZE] = {0};

/* send http get request */
char *get_weather(void)
{
    int fd;
    char hdr[HTTP_UP_HDR_SIZE] = {0};
    int32_t ret;
    http_rsp_info_t rsp_info;

    http_client_initialize();

    /* create socket */
    if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        printf("alloc socket fd fail\n");
        goto exit;
    }
    memset(&settings, 0, sizeof(settings));
    settings.socket       = fd;
    settings.server_name  = WEATHER_HOSTNAME;
    settings.req_buf      = req_buf;
    settings.req_buf_size = REQ_BUF_SIZE;

    /* httpc initialization */
    if ((httpc_handle = httpc_init(&settings)) == 0) {
        printf("http session init fail\n");
        close(fd);
        goto exit;
    }

    /* construct httc header: set accept content type */
    if ((httpc_construct_header(
            hdr, HTTP_UP_HDR_SIZE, "Accept",
            "text/xml,text/javascript,text/html,application/json")) < 0) {
        printf("http construct header fail\n");
        goto exit;
    }

    /* send get request */
    if ((httpc_send_request(httpc_handle, HTTP_GET, WEATHER_URI, hdr,
                            "application/json", NULL, 0)) != HTTP_SUCCESS) {
        printf("httpc_send_request fail\n");
        goto exit;
    }

    /* get response */
    if ((httpc_recv_response(httpc_handle, rsp_buf, RSP_BUF_SIZE, &rsp_info,
                             10000)) < 0) {
        printf("httpc_recv_response fail\n");
        goto exit;
    }

    printf("http session %x, buf size %d bytes, recv %d bytes data", httpc_handle,
        RSP_BUF_SIZE, rsp_info.rsp_len);
    // if (rsp_info.rsp_len > 0) {
    //     printf("%s", rsp_buf);
    // }

    if (rsp_info.message_complete) {
        // printf("message_complete");
        close(settings.socket);
        httpc_deinit(httpc_handle);
        return rsp_info.body_start;
    }

exit:
    close(settings.socket);
    httpc_deinit(httpc_handle);
    return NULL;
}

/* task for get weather */
static void get_weather_task(void *arg)
{
    char *weather_data = NULL;

    /* get weather data */
    if((weather_data = get_weather()) != NULL){
        aos_msleep(200);
        printf("********************** weather data **********************\r\n");
        printf("%s\r\n", weather_data);
        printf("**********************************************************\r\n");
        return;
    }

    printf("weather request error\r\n");
}

/* wifi event */
static void wifi_service_event(input_event_t *event, void *priv_data)
{
    static char ip[16] = {0};
    static int get_weather_started = 0;

    if (event->type != EV_WIFI && event->code != CODE_WIFI_ON_GOT_IP) {
        return;
    }

    netmgr_wifi_get_ip(ip);

    /* start up only once */
    if (get_weather_started == 1) {
        return;
    }

    /* check if ip is available */
    if (0 == strcmp(ip, "0.0.0.0")) {
        printf("ip invailable\n");
        return;
    }
    get_weather_started = 1;
    printf("wifi connected, ip:%s\n", ip);

    aos_task_new("get_weather", get_weather_task, NULL, 1024 * 4);
}

/* task for connect wifi */
static void wifi_connect(void *arg)
{
    /* network init */
    netmgr_init();
    netmgr_start(false);
    aos_msleep(100);

    /* connect to wifi */
    printf("\r\nConnecting to wifi: ssid:[%s], passwd:[%s]\r\n", WIFI_SSID, WIFI_PASSWD);
    netmgr_connect(WIFI_SSID, WIFI_PASSWD, 10 * 1000);
}
/**********************user code*************************/
int application_start(int argc, char *argv[])
{
#ifdef WITH_SAL
    sal_add_dev(NULL, NULL);
    sal_init();
#endif

    /* register wifi event */
    aos_register_event_filter(EV_WIFI, wifi_service_event, NULL);

    aos_task_new("wifi_connect", wifi_connect, NULL, 2048);

    /* loop for schedule */
    aos_loop_run();
}

編譯運行

點擊編譯和燒錄。運行後，在串口日誌最後面就能看的獲取到的天氣信息。

運行效果：

[   0.050]<A>AOS sensor:  drv_acc_st_lsm6dsl_init successfully

[   0.060]<A>AOS sensor:  drv_gyro_st_lsm6dsl_init gyro do not need reset

[   0.070]<A>AOS sensor:  drv_gyro_st_lsm6dsl_init successfully

[   0.080]<A>AOS sensor:  drv_als_liteon_ltr553_init successfully

[   0.090]<A>AOS sensor:  drv_ps_liteon_ltr553_init successfully

[   0.100]<A>AOS sensor:  drv_baro_bosch_bmp280_init successfully

[   0.110]<A>AOS sensor:  drv_mag_memsic_mmc3680kj_init successfully

[   0.120]<A>AOS sensor:  drv_humi_sensirion_shtc1_init successfully

[   0.130]<A>AOS sensor:  drv_temp_sensirion_shtc1_init successfully

             Welcome to AliOS Things
[   0.150]<E>sal_wifi Uart dev is not configured, use the default cfg

uart 1 enter uart_receive_start_dma instance 0x40004800ip invailable

Connecting to wifi: ssid:[aiot], passwd:[12345678]
wifi connected, ip:192.168.43.111
[[hhttttppcc]][[000088665500]]  hhttttppcc__sseenndd__rreeqquueesstt,,  sseenndd  rreeqquueesstt  hheeaaddeerr

vGoErTk s/pdaactea//gsikt/h1u0b1/2A1l0i1O0S1-.Thhtimnlg sH/TbToPa/r1d./1d
2Ulsoepre-rAkgietn/ta:o sA/lbioOaSr-dH_TcTlPi-.Ccl i2e1n6t
1

Cache-Control: no-cache
Connection: close
Host: www.weather.com.cn
Accept: text/xml,text/javascript,text/html,application/json
Content-Type: application/json


socket 0, len 238
[httpc][009130] httpc_send_request, connect 0
[httpc][009160] httpc_send_request, send 238, ret 0
[httpc][019170] on_message_begin, HTTP response (headers), method GET
[httpc][019170] on_status, HTTP response status OK
[httpc][019180] print_header_field, len 4, Date
[httpc][019190] print_header_field, len 29, Wed, 09 Oct 2019 07:32:13 GMT
[httpc][019200] print_header_field, len 12, Content-Type
[httpc][019200] print_header_field, len 9, text/html
[httpc][019210] print_header_field, len 17, Transfer-Encoding
[httpc][019220] print_header_field, len 7, chunked
[httpc][019220] print_header_field, len 10, Connection
[httpc][019230] print_header_field, len 5, close
[httpc][019240] print_header_field, len 6, Server
[httpc][019240] print_header_field, len 9, openresty
[httpc][019250] print_header_field, len 16, X-Xss-Protection
[httpc][019260] print_header_field, len 1, 1
[httpc][019260] print_header_field, len 10, Set-Cookie
[httpc][019270] print_header_field, len 8, HttpOnly
[httpc][019280] print_header_field, len 3, Age
[httpc][019280] print_header_field, len 4, 2068
[httpc][019290] print_header_field, len 5, X-Via
[httpc][019300] print_header_field, len 125, 1.1 PSbjsdBGPvu28:10 (Cdn Cache Server V2.0), 1.1 zhdx147:10 (Cdn Cache Server V2.0), 1.1 huadxin69:7 (Cdn Cache Server V2.0)
[httpc][019320] on_headers_complete, headers complete
[httpc][019320] on_message_complete, HTTP GET response (complete)
http session 20002298, buf size 4096 bytes, recv 578 bytes data[  19.340]<E>sal_wifi HAL_SAL_Close 778 failed
********************** weather data **********************
{"weatherinfo":{"city":"杭州","cityid":"101210101","temp":"24.8","WD":"東北風","WS":"小於3級","SD":"81%","AP":"1000.3hPa","njd":"暫無實況","WSE":"<3","time":"17:50","sm":"2.1","isRadar":"1","Radar":"JC_RADAR_AZ9571_JB"}}

**********************************************************

參考文檔

• AliOS Things 3.0 應用開發指南
• 使用AliOS Things3.0 快速構建用戶應用BlinkAPP