更新时间:2024-06-27 GMT+08:00

C++

操作场景

使用C++语言调用APP认证的API时,您需要先获取SDK,参考API调用示例调用API。

前提条件

  1. 已获取API的调用信息,具体参见认证前准备
  2. 安装openssl库。
    apt-get install libssl-dev
  3. 安装curl库。
    apt-get install libcurl4-openssl-dev

获取SDK

请登录API网关控制台,参考《API网关用户指南》的“SDK”章节,进入SDK页面并下载SDK。

或直接下载SDK的最新版本,获取“ApiGateway-cpp-sdk.zip”压缩包,解压后目录结构如下:

名称

说明

hasher.cpp

SDK代码

hasher.h

header.h

RequestParams.cpp

RequestParams.h

signer.cpp

signer.h

Makefile

Makefile文件

main.cpp

示例代码

调用API示例

  1. 在main.cpp中加入以下引用。

    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <curl/curl.h>
    #include "signer.h"

  2. 生成一个新的Signer, 填入AppKey和AppSecret。

    1. 本示例以AK和SK保存在环境变量中为例,运行本示例前请先在本地环境中设置环境变量HUAWEICLOUD_SDK_AK和HUAWEICLOUD_SDK_SK。以Linux系统为例在本地将已获取的AK/SK设置为环境变量。
      1. 打开终端,输入以下命令打开环境变量配置文件。

        vi ~/.bashrc

      2. 设置环境变量,保存文件并退出编辑器。
        export HUAWEICLOUD_SDK_AK="已获取AK值" 
        export HUAWEICLOUD_SDK_SK="已获取SK值" 
      3. 输入以下命令使配置文件生效。

        source ~/.bashrc

    2. 生成一个新的Signer,填入已设置的环境变量。
      // Directly writing AK/SK in code is risky. For security, encrypt your AK/SK and store them in the configuration file or environment variables.
      // In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, set environment variables HUAWEICLOUD_SDK_AK and HUAWEICLOUD_SDK_SK.
      Signer signer(getenv("HUAWEICLOUD_SDK_AK"), getenv("HUAWEICLOUD_SDK_SK"));

  3. 生成一个新的RequestParams,指定方法名、域名、请求uri、查询字符串和body。

     RequestParams* request = new RequestParams("POST", "c967a237-cd6c-470e-906f-a8655461897e.apigw.exampleRegion.com", "/app1",
            "Action=ListUsers&Version=2010-05-08", "demo");

  4. 给请求添加x-stage头,内容为环境名。如果有需要,添加需要签名的其他头域。

    request->addHeader("x-stage", "RELEASE");

  5. 进行签名,执行此函数会将生成的签名头加入request变量中。

    signer.createSignature(request);

  6. 使用curl库访问API,查看访问结果。

    static size_t
    WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
    {
        size_t realsize = size * nmemb;
        struct MemoryStruct *mem = (struct MemoryStruct *)userp;
    
        mem->memory = (char*)realloc(mem->memory, mem->size + realsize + 1);
        if (mem->memory == NULL) {
            /* out of memory! */
            printf("not enough memory (realloc returned NULL)\n");
            return 0;
        }
    
        memcpy(&(mem->memory[mem->size]), contents, realsize);
        mem->size += realsize;
        mem->memory[mem->size] = 0;
    
        return realsize;
    }
    
    //send http request using curl library
    int perform_request(RequestParams* request)
    {
        CURL *curl;
        CURLcode res;
        struct MemoryStruct resp_header;
        resp_header.memory = (char*)malloc(1);
        resp_header.size = 0;
        struct MemoryStruct resp_body;
        resp_body.memory = (char*)malloc(1);
        resp_body.size = 0;
    
        curl_global_init(CURL_GLOBAL_ALL);
        curl = curl_easy_init();
    
        curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, request->getMethod().c_str());
        std::string url = "http://" + request->getHost() + request->getUri() + "?" + request->getQueryParams();
        curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
        struct curl_slist *chunk = NULL;
        std::set<Header>::iterator it;
        for (auto header : *request->getHeaders()) {
            std::string headerEntry = header.getKey() + ": " + header.getValue();
            printf("%s\n", headerEntry.c_str());
            chunk = curl_slist_append(chunk, headerEntry.c_str());
        }
        printf("-------------\n");
        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
        curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS, request->getPayload().c_str());
        curl_easy_setopt(curl, CURLOPT_NOBODY, 0L);
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
        curl_easy_setopt(curl, CURLOPT_HEADERDATA, (void *)&resp_header);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&resp_body);
        //curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
        res = curl_easy_perform(curl);
        if (res != CURLE_OK) {
            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
        }
        else {
            long status;
            curl_easy_getinfo(curl, CURLINFO_HTTP_CODE, &status);
            printf("status %d\n", status);
            printf(resp_header.memory);
            printf(resp_body.memory);
        }
        free(resp_header.memory);
        free(resp_body.memory);
        curl_easy_cleanup(curl);
    
        curl_global_cleanup();
    
        return 0;
    }

  7. 运行make命令编译,得到可执行文件main,执行main文件,查看结果。