使用Libcurl作为HTTP客户端请求-优快云博客

本文展示了一个使用C++编写的简易网络请求库，通过CURL库实现HTTP POST请求。该库包括HttpRequest类，用于初始化CURL，设置请求参数，执行请求并处理响应。

直接上代码

HttpRequest.h

#ifndef HTTP_REQUEST_H__
#define HTTP_REQUEST_H__
#include <string>
extern "C" {
#include <curl.h>
#include <easy.h>
};

class HttpRequest {
public:
	HttpClient();
	~HttpClient();

	std::string DoPost(const char* url, const char* params);

	static size_t CurlWriteData(void* data, size_t size, size_t nmemb, void* p);

	void AppendData(void* data, size_t size);

private:
	CURL* curl_;
	CURLcode curl_code_;
	curl_slist* curl_header_list_;
	std::string response_;
};

#endif // HTTP_REQUEST_H__

HttpRequest.cpp

#include "./http_request.h"

HttpRequest::HttpRequest() {
	curl_header_list_ = NULL;
}
HttpRequest::~HttpRequest() {
	if (curl_header_list_ != NULL) {
		curl_slist_free_all(curl_header_list_);
	}
}

size_t HttpRequest::CurlWriteData(void* data, size_t size, size_t nmemb, void *p) {
	HttpClient* _this = (HttpClient*)p;
	printf("nmemb: %d", nmemb);
	_this->AppendData(data, nmemb);
	return size * nmemb;
}


void HttpRequest::AppendData(void* data, size_t size) {
	response_.append((const char*)data, size);
}

std::string HttpRequest::DoPost(const char* url, const char* params) {
	curl_ = curl_easy_init();
	if (curl_ == NULL) {
		return "";
	}
	response_ = "";

	curl_easy_setopt(curl_, CURLOPT_TIMEOUT, 60); // 只等待60秒
	curl_easy_setopt(curl_, CURLOPT_URL, url);
	/* Now specify the POST data */
	curl_easy_setopt(curl_, CURLOPT_POSTFIELDS, params);
	curl_easy_setopt(curl_, CURLOPT_WRITEFUNCTION, HttpClient::CurlWriteData); 
	curl_easy_setopt(curl_, CURLOPT_WRITEDATA, this);
	curl_easy_setopt(curl_, CURLOPT_POST, 1);

	if (curl_header_list_ != NULL)
		curl_easy_setopt(curl_, CURLOPT_HTTPHEADER, curl_header_list_);

	/* Perform the request, res will get the return code */
	curl_code_ = curl_easy_perform(curl_);
	/* Check for errors */
	if (curl_code_ != CURLE_OK) {
		//printf("curl_easy_perform() failed: %s\n",curl_easy_strerror(curl_code_));
	}else {
		// 请求成功
	}
	/* always cleanup */
	curl_easy_cleanup(curl_);

	return response_;
}