The following is a C++ downloader program using the Wt library to download audio files. The code used in this program.
#include <Wt/Wt.h>
#include <Wt/Http/DiskCache.h>
#include <Wt/Http/HttpClient.h>
//
Define a function to get the server
static std::string get_proxy() {
/ / Use Wt::Http::get() function to send HTTP request
Wt::Http::Response response = Wt::Http::get("");
//
Check the response status
if (response.status() ! = Wt::Http::StatusOk) {
std::cerr << "Failed to get proxy server: " << response.statusText() << std::endl;
return "";
}
//
Parse JSON response
Wt ::Json::Value json = Wt::Json::parse(response.text());
return json.toString();
}
//
Define a class to handle audio download
class AudioDownloader : public Wt::WObject {
public:
// Constructor
AudioDownloader(const std::string& url)
: Wt::WObject()
, url_(url)
{
// Initialize the downloader
init();
}
private
:
// Initialize the downloader
void init() {
// Create a cache directory
cache_dir_ = Wt::Http::DiskCache::createCacheDirectory();
//
Create an HTTP client
client_ = Wt::Http::HttpClient::create();
//
Set up a proxy Server
set_proxy(get_proxy());
//
Start download
download();
}
//
Set server
void set_proxy(const std::string& proxy) {
if (!proxy.empty()) {
client_->setProxy(proxy ); }
}
//
Start
downloading
void download() {
// Use HTTP client to send GET request
Wt::Http::Response response = client_->get(url_);
//
Check response status
if (response. status() == Wt::Http::StatusOk) {
// Save the audio file to the cache directory
Wt::Http::DiskCache::saveResponseToCache(cache_dir_, url_, response);
} else {
std::cerr << " Failed to download audio: " << response.statusText() << std::endl;
}
}
//
Callback function after the audio download is completed
void onDownloadComplete() {
// Perform operations after the download is completed
// ...
}
private
:
std::string url_;
std::unique_ptr<Wt::Http::HttpClient> client_;
std::string cache_dir_;
};
//
Main function
int main(int argc, char** argv) {
//Initialize Wt library
Wt::WEnvironment::initialize(argc, argv);
//
Create an audio downloader
AudioDownloader downloader("http://www.qq.com/audio/");
//
Start downloading
downloader.onDownloadComplete() ;
//
Wait for the user to input keyboard keys
Wt::WEnvironment::waitForKey();
//
Destroy the Wt library
Wt::WEnvironment::uninitialize();
return
0;
}
This program first obtains the IP address of the server and then downloads the audio file using the HttpClient class of the Wt library. After the download is complete, the program calls onDownloadComplete()the function. In this function you can add the code that needs to be executed.