有什么方法可以简单地用c++发出HTTP请求吗?具体来说，我想下载一个页面(一个API)的内容，并检查内容，看看它是否包含1或0。是否也可以将内容下载到字符串中?
当前回答
这是我关于cURL的最小包装器，它能够以字符串的形式获取网页。例如，这对于单元测试很有用。它基本上是一个围绕C代码的RAII包装器。
在你的机器上安装libcurl libcurl-devel或等效的。
使用的例子:
CURLplusplus client;
string x = client.Get("http://google.com");
string y = client.Get("http://yahoo.com");
类的实现:
#include <curl/curl.h>
class CURLplusplus
{
private:
CURL* curl;
stringstream ss;
long http_code;
public:
CURLplusplus()
: curl(curl_easy_init())
, http_code(0)
{
}
~CURLplusplus()
{
if (curl) curl_easy_cleanup(curl);
}
std::string Get(const std::string& url)
{
CURLcode res;
curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, this);
ss.str("");
http_code = 0;
res = curl_easy_perform(curl);
if (res != CURLE_OK)
{
throw std::runtime_error(curl_easy_strerror(res));
}
curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &http_code);
return ss.str();
}
long GetHttpCode()
{
return http_code;
}
private:
static size_t write_data(void *buffer, size_t size, size_t nmemb, void *userp)
{
return static_cast<CURLplusplus*>(userp)->Write(buffer,size,nmemb);
}
size_t Write(void *buffer, size_t size, size_t nmemb)
{
ss.write((const char*)buffer,size*nmemb);
return size*nmemb;
}
};
其他回答
cesanta的猫鼬库似乎也支持这一点:https://github.com/cesanta/mongoose/blob/6.17/examples/http_client/http_client.c
你可以使用ACE这样做:
#include "ace/SOCK_Connector.h"
int main(int argc, ACE_TCHAR* argv[])
{
//HTTP Request Header
char* szRequest = "GET /video/nice.mp4 HTTP/1.1\r\nHost: example.com\r\n\r\n";
int ilen = strlen(szRequest);
//our buffer
char output[16*1024];
ACE_INET_Addr server (80, "example.com");
ACE_SOCK_Stream peer;
ACE_SOCK_Connector connector;
int ires = connector.connect(peer, server);
int sum = 0;
peer.send(szRequest, ilen);
while (true)
{
ACE_Time_Value timeout = ACE_Time_Value(15);
int rc = peer.recv_n(output, 16*1024, &timeout);
if (rc == -1)
{
break;
}
sum += rc;
}
peer.close();
printf("Bytes transffered: %d",sum);
return 0;
}
如果你想要c++的解决方案，你可以使用Qt，它有一个QHttp类。
你可以查看文档:
http->setHost("qt.nokia.com");
http->get(QUrl::toPercentEncoding("/index.html"));
Qt还有很多可以在普通c++应用程序中使用的功能。
这是我关于cURL的最小包装器，它能够以字符串的形式获取网页。例如，这对于单元测试很有用。它基本上是一个围绕C代码的RAII包装器。
在你的机器上安装libcurl libcurl-devel或等效的。
使用的例子:
CURLplusplus client;
string x = client.Get("http://google.com");
string y = client.Get("http://yahoo.com");
类的实现:
#include <curl/curl.h>
class CURLplusplus
{
private:
CURL* curl;
stringstream ss;
long http_code;
public:
CURLplusplus()
: curl(curl_easy_init())
, http_code(0)
{
}
~CURLplusplus()
{
if (curl) curl_easy_cleanup(curl);
}
std::string Get(const std::string& url)
{
CURLcode res;
curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, this);
ss.str("");
http_code = 0;
res = curl_easy_perform(curl);
if (res != CURLE_OK)
{
throw std::runtime_error(curl_easy_strerror(res));
}
curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &http_code);
return ss.str();
}
long GetHttpCode()
{
return http_code;
}
private:
static size_t write_data(void *buffer, size_t size, size_t nmemb, void *userp)
{
return static_cast<CURLplusplus*>(userp)->Write(buffer,size,nmemb);
}
size_t Write(void *buffer, size_t size, size_t nmemb)
{
ss.write((const char*)buffer,size*nmemb);
return size*nmemb;
}
};
你可以使用embeddedRest库。它是一个轻量级的头文件库。所以很容易将它包含到你的项目中，它不需要编译，因为里面没有。cpp文件。
从自述文件中请求示例。Md from repo:
#include "UrlRequest.hpp"
//...
UrlRequest request;
request.host("api.vk.com");
const auto countryId = 1;
const auto count = 1000;
request.uri("/method/database.getCities",{
{ "lang", "ru" },
{ "country_id", countryId },
{ "count", count },
{ "need_all", "1" },
});
request.addHeader("Content-Type: application/json");
auto response = std::move(request.perform());
if (response.statusCode() == 200) {
cout << "status code = " << response.statusCode() << ", body = *" << response.body() << "*" << endl;
}else{
cout << "status code = " << response.statusCode() << ", description = " << response.statusDescription() << endl;
}
