1 库依赖

Websocket++/Websocketpp依赖于boost(使用boost 1.74),Websocket++ 0.8.2版本,因为暂时没有使用wss,所以没有集成Openssl。

2 根据官方示例代码修改封装的WebsocketClient类

2.1 WebsocketClient代码

  • WebsocketClient.h
#ifndef WEBSOCKET_CLIENT_H
#define WEBSOCKET_CLIENT_H
// 不包含TLS Client
#include <websocketpp/config/asio_no_tls_client.hpp>
#include <websocketpp/client.hpp>
// 包含TLS Client
// #include <websocketpp/config/asio_client.hpp>
// #include <websocketpp/client.hpp>
#include <websocketpp/common/thread.hpp>
#include <websocketpp/common/memory.hpp>
#include <string>
#include <locale>
#include <codecvt>
typedef websocketpp::client<websocketpp::config::asio_client> client;
static std::wstring string_to_wstring(const std::string &s)
{
using default_convert = std::codecvt<wchar_t, char, std::mbstate_t>;
static std::wstring_convert<default_convert>conv(new default_convert("CHS"));
return conv.from_bytes(s);
}
static std::string wstring_to_string(const std::wstring &s)
{
using default_convert = std::codecvt<wchar_t, char, std::mbstate_t>;
static std::wstring_convert<default_convert>conv(new default_convert("CHS"));
return conv.to_bytes(s);
}
static std::string ansi_to_utf8(const std::string &s)
{
static std::wstring_convert<std::codecvt_utf8<wchar_t> > conv;
return conv.to_bytes(string_to_wstring(s));
}
static std::string utf8_to_ansi(const std::string& s)
{
static std::wstring_convert<std::codecvt_utf8<wchar_t> > conv;
return wstring_to_string(conv.from_bytes(s));
}
// 保存一个连接的metadata
class connection_metadata {
public:
typedef websocketpp::lib::shared_ptr<connection_metadata> ptr;
connection_metadata(websocketpp::connection_hdl hdl, std::string url)
: m_Hdl(hdl)
, m_Status("Connecting")
, m_Url(url)
, m_Server("N/A")
{}
void on_open(client * c, websocketpp::connection_hdl hdl) 
{
m_Status = "Open";
client::connection_ptr con = c->get_con_from_hdl(hdl);
m_Server = con->get_response_header("Server");
}
void on_fail(client * c, websocketpp::connection_hdl hdl)
{
m_Status = "Failed";
client::connection_ptr con = c->get_con_from_hdl(hdl);
m_Server = con->get_response_header("Server");
m_Error_reason = con->get_ec().message();
}
void on_close(client * c, websocketpp::connection_hdl hdl)
{
m_Status = "Closed";
client::connection_ptr con = c->get_con_from_hdl(hdl);
std::stringstream s;
s << "close code: " << con->get_remote_close_code() << " ("
<< websocketpp::close::status::get_string(con->get_remote_close_code())
<< "), close reason: " << con->get_remote_close_reason();
m_Error_reason = s.str();
}
void on_message(websocketpp::connection_hdl, client::message_ptr msg)
{
if (msg->get_opcode() == websocketpp::frame::opcode::text) 
{
std::string message = utf8_to_ansi(msg->get_payload());
std::cout << "收到来自服务器的消息:" << message << std::endl;
}
else 
{
std::string message = websocketpp::utility::to_hex(msg->get_payload());
}
}
websocketpp::connection_hdl get_hdl() const
{
return m_Hdl;
}
std::string get_status() const
{
return m_Status;
}
private:
websocketpp::connection_hdl m_Hdl;  // websocketpp表示连接的编号
std::string m_Status;               // 连接自动状态
std::string m_Url;                  // 连接的URI
std::string m_Server;               // 服务器信息
std::string m_Error_reason;         // 错误原因
};
class WebsocketClient
{
public:
WebsocketClient();
virtual~WebsocketClient();
public:
bool Connect(std::string const & url);
bool Close(std::string reason = "");
bool Send(std::string message);
connection_metadata::ptr GetConnectionMetadataPtr();
private:
connection_metadata::ptr m_ConnectionMetadataPtr;
client m_WebsocketClient;
websocketpp::lib::shared_ptr<websocketpp::lib::thread> m_Thread; // 线程
};
#endif // !WEBSOCKET_ENDPOINT_H
  • WebsocketClient.cpp
#include "WebsocketClient.h"
WebsocketClient::WebsocketClient()
{
m_WebsocketClient.clear_access_channels(websocketpp::log::alevel::all);  // 开启全部接入日志级别
m_WebsocketClient.clear_error_channels(websocketpp::log::elevel::all);   // 开启全部错误日志级别
m_WebsocketClient.init_asio();       // 初始化asio
m_WebsocketClient.start_perpetual(); // 避免请求为空时退出,实际上,也是避免asio退出
// 独立运行client::run()的线程,主要是避免阻塞
m_Thread = websocketpp::lib::make_shared<websocketpp::lib::thread>(&client::run, &m_WebsocketClient);
}
WebsocketClient::~WebsocketClient()
{
m_WebsocketClient.stop_perpetual();
if (m_ConnectionMetadataPtr != nullptr && m_ConnectionMetadataPtr->get_status() == "Open")
{
websocketpp::lib::error_code ec;
m_WebsocketClient.close(m_ConnectionMetadataPtr->get_hdl(), websocketpp::close::status::going_away, "", ec); // 关闭连接
if (ec) {
std::cout << "> Error initiating close: " << ec.message() << std::endl;
}
}
m_Thread->join();
}
bool WebsocketClient::Connect(std::string const & url)
{
websocketpp::lib::error_code ec;
// 创建connect的共享指针,注意,此时创建并没有实际建立
client::connection_ptr con = m_WebsocketClient.get_connection(url, ec);  
if (ec) {
std::cout << "> Connect initialization error: " << ec.message() << std::endl;
return false;
}
// 创建连接的metadata信息,并保存
connection_metadata::ptr metadata_ptr = websocketpp::lib::make_shared<connection_metadata>(con->get_handle(), url);
m_ConnectionMetadataPtr = metadata_ptr;
// 注册连接打开的Handler
con->set_open_handler(websocketpp::lib::bind(
&connection_metadata::on_open,
metadata_ptr,
&m_WebsocketClient,
websocketpp::lib::placeholders::_1
));
// 注册连接失败的Handler
con->set_fail_handler(websocketpp::lib::bind(
&connection_metadata::on_fail,
metadata_ptr,
&m_WebsocketClient,
websocketpp::lib::placeholders::_1
));
// 注册连接关闭的Handler
con->set_close_handler(websocketpp::lib::bind(
&connection_metadata::on_close,
metadata_ptr,
&m_WebsocketClient,
websocketpp::lib::placeholders::_1
));
// 注册连接接收消息的Handler
con->set_message_handler(websocketpp::lib::bind(
&connection_metadata::on_message,
metadata_ptr,
websocketpp::lib::placeholders::_1,
websocketpp::lib::placeholders::_2
));
// 进行连接
m_WebsocketClient.connect(con);
std::cout << "Websocket连接成功" << std::endl;
return true;
}
bool WebsocketClient::Close(std::string reason)
{
websocketpp::lib::error_code ec;
if (m_ConnectionMetadataPtr != nullptr)
{
int close_code = websocketpp::close::status::normal;
// 关闭连接
m_WebsocketClient.close(m_ConnectionMetadataPtr->get_hdl(), close_code, reason, ec);
if (ec) {
std::cout << "> Error initiating close: " << ec.message() << std::endl;
return false;
}
std::cout << "关闭Websocket连接成功" << std::endl;
}
return true;
}
bool WebsocketClient::Send(std::string message)
{
websocketpp::lib::error_code ec;
if (m_ConnectionMetadataPtr != nullptr)
{
// 连接发送数据
m_WebsocketClient.send(m_ConnectionMetadataPtr->get_hdl(), ansi_to_utf8(message), websocketpp::frame::opcode::text, ec);
if (ec) {
std::cout << "> Error sending message: " << ec.message() << std::endl;
return false;
}
std::cout << "发送数据成功" << std::endl;
}
return true;
}
connection_metadata::ptr WebsocketClient::GetConnectionMetadataPtr()
{
return m_ConnectionMetadataPtr;
}

2.2 WebsocketClient类使用代码

#include "WebsocketClient.h"
int main() {
bool done = false;
std::string input;
WebsocketClient endpoint;
while (!done) {
std::cout << "Enter Command: ";
std::getline(std::cin, input);
if (input == "quit") {
done = true;
}
else if (input == "help") {
std::cout
<< "\nCommand List:\n"
<< "connect <ws uri>\n"
<< "send <message>\n"
<< "close [<close code:default=1000>] [<close reason>]\n"
<< "help: Display this help text\n"
<< "quit: Exit the program\n"
<< std::endl;
}
else if (input.substr(0, 7) == "connect") {
endpoint.Connect(input.substr(8));
}
else if (input.substr(0, 4) == "send") {
std::stringstream ss(input);
std::string cmd;
int id;
std::string message;
ss >> cmd;
std::getline(ss, message);
endpoint.Send(message);
}
else if (input.substr(0, 5) == "close") {
std::stringstream ss(input);
std::string cmd;
std::string reason;
ss >> cmd ;
std::getline(ss, reason);
endpoint.Close(reason);
}
else if (input.substr(0, 4) == "quit") {
done = true;
}
else {
std::cout << "> Unrecognized Command" << std::endl;
}
}
return 0;
}

3 Websocket++官方编写客户端示例教程

可参考链接:https://docs.websocketpp.org/md_tutorials_utility_client_utility_client.html

也可在Websocket++的文件夹\tutorials\utility_client找到该示例!
或者在Websocket++的文件夹\example\scratch_client找到该示例!

4 与Websocket++官方示例客户端的不同

  • 增加ansi与utf-8编码转换,中文字符不再乱码
  • 不适用官方使用id管理多个链接方式,这里认为的客户端只有一个长连接,而WebsocketClient只维护一个长连接即可

2020年9月16日更新:修改WebsocketClient类

修改信息
- 将open,close,message等回调函数移动到WebsocketClient内部
- 新增设置回调函数的公共接口

WebsocketClient.h

#ifndef WEBSOCKET_CLIENT_H
#define WEBSOCKET_CLIENT_H
// 不包含TLS Client
#include <websocketpp/config/asio_no_tls_client.hpp>
#include <websocketpp/client.hpp>
// 包含TLS Client
// #include <websocketpp/config/asio_client.hpp>
// #include <websocketpp/client.hpp>
#include <websocketpp/common/thread.hpp>
#include <websocketpp/common/memory.hpp>
#include <string>
#include <locale>
#include <codecvt>
typedef websocketpp::client<websocketpp::config::asio_client> client;
static std::wstring string_to_wstring(const std::string &s)
{
using default_convert = std::codecvt<wchar_t, char, std::mbstate_t>;
static std::wstring_convert<default_convert>conv(new default_convert("CHS"));
return conv.from_bytes(s);
}
static std::string wstring_to_string(const std::wstring &s)
{
using default_convert = std::codecvt<wchar_t, char, std::mbstate_t>;
static std::wstring_convert<default_convert>conv(new default_convert("CHS"));
return conv.to_bytes(s);
}
static std::string ansi_to_utf8(const std::string &s)
{
static std::wstring_convert<std::codecvt_utf8<wchar_t> > conv;
return conv.to_bytes(string_to_wstring(s));
}
static std::string utf8_to_ansi(const std::string& s)
{
static std::wstring_convert<std::codecvt_utf8<wchar_t> > conv;
return wstring_to_string(conv.from_bytes(s));
}
typedef std::function<void()> OnOpenFunc;
typedef std::function<void()> OnFailFunc;
typedef std::function<void()> OnCloseFunc;
typedef std::function<void(const std::string& message)> OnMessageFunc;
class WebsocketClient 
{
public:
WebsocketClient();
virtual~WebsocketClient();
public:
bool Connect(std::string const & url);
bool Close(std::string reason = "");
bool Send(std::string message);
connection_metadata::ptr GetConnectionMetadataPtr();
void OnOpen(client * c, websocketpp::connection_hdl hdl);
void OnFail(client * c, websocketpp::connection_hdl hdl);
void OnClose(client * c, websocketpp::connection_hdl hdl);
void OnMessage(websocketpp::connection_hdl, client::message_ptr msg);
void SetOnOpenFunc(OnOpenFunc func);
void SetOnFailFunc(OnFailFunc func);
void SetOnCloseFunc(OnCloseFunc func);
void SetMessageFunc(OnMessageFunc func);
private:
connection_metadata::ptr m_ConnectionMetadataPtr;
client m_WebsocketClient;
websocketpp::lib::shared_ptr<websocketpp::lib::thread> m_Thread; // 线程
OnOpenFunc m_OnOpenFunc;
OnFailFunc m_OnFailFunc;
OnCloseFunc m_OnCloseFunc;
OnMessageFunc m_MessageFunc;
};
#endif // !WEBSOCKET_ENDPOINT_H

WebsocketClient.cpp

#include "WebsocketClient.h"
WebsocketClient::WebsocketClient()
{
m_WebsocketClient.clear_access_channels(websocketpp::log::alevel::all);  // 开启全部接入日志级别
m_WebsocketClient.clear_error_channels(websocketpp::log::elevel::all);   // 开启全部错误日志级别
m_WebsocketClient.init_asio();       // 初始化asio
m_WebsocketClient.start_perpetual(); // 避免请求为空时退出,实际上,也是避免asio退出
// 独立运行client::run()的线程,主要是避免阻塞
m_Thread = websocketpp::lib::make_shared<websocketpp::lib::thread>(&client::run, &m_WebsocketClient);
m_OnOpenFunc = nullptr;
m_OnFailFunc = nullptr;
m_OnCloseFunc = nullptr;
m_MessageFunc = nullptr;
}
WebsocketClient::~WebsocketClient()
{
m_WebsocketClient.stop_perpetual();
if (m_ConnectionMetadataPtr != nullptr && m_ConnectionMetadataPtr->get_status() == "Open")
{
websocketpp::lib::error_code ec;
m_WebsocketClient.close(m_ConnectionMetadataPtr->get_hdl(), websocketpp::close::status::going_away, "", ec); // 关闭连接
if (ec) {
std::cout << "> Error initiating close: " << ec.message() << std::endl;
}
}
m_Thread->join();
}
bool WebsocketClient::Connect(std::string const & url)
{
websocketpp::lib::error_code ec;
// 创建connect的共享指针,注意,此时创建并没有实际建立
client::connection_ptr con = m_WebsocketClient.get_connection(url, ec);  
if (ec) {
std::cout << "> Connect initialization error: " << ec.message() << std::endl;
return false;
}
// 创建连接的metadata信息,并保存
connection_metadata::ptr metadata_ptr = websocketpp::lib::make_shared<connection_metadata>(con->get_handle(), url);
m_ConnectionMetadataPtr = metadata_ptr;
// 注册连接打开的Handler
//con->set_open_handler(websocketpp::lib::bind(
//  &connection_metadata::on_open,
//  metadata_ptr,
//  &m_WebsocketClient,
//  websocketpp::lib::placeholders::_1
//));
con->set_open_handler(websocketpp::lib::bind(
&WebsocketClient::OnOpen,
this,
&m_WebsocketClient,
websocketpp::lib::placeholders::_1
));
// 注册连接失败的Handler
//con->set_fail_handler(websocketpp::lib::bind(
//  &connection_metadata::on_fail,
//  metadata_ptr,
//  &m_WebsocketClient,
//  websocketpp::lib::placeholders::_1
//));
con->set_fail_handler(websocketpp::lib::bind(
&WebsocketClient::OnFail,
this,
&m_WebsocketClient,
websocketpp::lib::placeholders::_1
));
// 注册连接关闭的Handler
//con->set_close_handler(websocketpp::lib::bind(
//  &connection_metadata::on_close,
//  metadata_ptr,
//  &m_WebsocketClient,
//  websocketpp::lib::placeholders::_1
//));
con->set_close_handler(websocketpp::lib::bind(
&WebsocketClient::OnClose,
this,
&m_WebsocketClient,
websocketpp::lib::placeholders::_1
));
// 注册连接接收消息的Handler
//con->set_message_handler(websocketpp::lib::bind(
//  &connection_metadata::on_message,
//  metadata_ptr,
//  websocketpp::lib::placeholders::_1,
//  websocketpp::lib::placeholders::_2
//));
con->set_message_handler(websocketpp::lib::bind(
&WebsocketClient::OnMessage,
this,
websocketpp::lib::placeholders::_1,
websocketpp::lib::placeholders::_2
));
// 进行连接
m_WebsocketClient.connect(con);
std::cout << "Websocket连接成功" << std::endl;
// 注意,不能在Websocket连接完成之后马上就发送消息,不然会出现Invalid State的错误,
// 导致消息发送不成功,所以在连接成功之后,主线程休眠1秒
std::this_thread::sleep_for(std::chrono::milliseconds(1000));
return true;
}
bool WebsocketClient::Close(std::string reason)
{
websocketpp::lib::error_code ec;
if (m_ConnectionMetadataPtr != nullptr)
{
int close_code = websocketpp::close::status::normal;
// 关闭连接
m_WebsocketClient.close(m_ConnectionMetadataPtr->get_hdl(), close_code, reason, ec);
if (ec) {
std::cout << "> Error initiating close: " << ec.message() << std::endl;
return false;
}
std::cout << "关闭Websocket连接成功" << std::endl;
}
return true;
}
bool WebsocketClient::Send(std::string message)
{
websocketpp::lib::error_code ec;
if (m_ConnectionMetadataPtr != nullptr)
{
// 连接发送数据
m_WebsocketClient.send(m_ConnectionMetadataPtr->get_hdl(),ansi_to_utf8(message), websocketpp::frame::opcode::text, ec);
if (ec) 
{
std::cout << "> Error sending message: " << ec.message() << std::endl;
std::string errorMessage = ec.message();
return false;
}
std::cout << "发送数据成功" << std::endl;
}
return true;
}
connection_metadata::ptr WebsocketClient::GetConnectionMetadataPtr()
{
return m_ConnectionMetadataPtr;
}
void WebsocketClient::OnOpen(client * c, websocketpp::connection_hdl hdl)
{
if (m_OnOpenFunc != nullptr)
{
m_OnOpenFunc();
}
}
void WebsocketClient::OnFail(client * c, websocketpp::connection_hdl hdl)
{
if (m_OnFailFunc != nullptr)
{
m_OnFailFunc();
}
}
void WebsocketClient::OnClose(client * c, websocketpp::connection_hdl hdl)
{
if (m_OnCloseFunc != nullptr)
{
m_OnCloseFunc();
}
}
void WebsocketClient::OnMessage(websocketpp::connection_hdl, client::message_ptr msg)
{
if (msg->get_opcode() == websocketpp::frame::opcode::text)
{
std::string message = utf8_to_ansi(msg->get_payload());
//std::cout << "收到来自服务器的消息:" << message << std::endl;
if (m_MessageFunc != nullptr)
{
m_MessageFunc(message);
}   
}
else
{
std::string message = websocketpp::utility::to_hex(msg->get_payload());
}
}
void WebsocketClient::SetOnOpenFunc(OnOpenFunc func)
{
m_OnOpenFunc = func;
}
void WebsocketClient::SetOnFailFunc(OnFailFunc func)
{
m_OnFailFunc = func;
}
void WebsocketClient::SetOnCloseFunc(OnCloseFunc func)
{
m_OnCloseFunc = func;
}
void WebsocketClient::SetMessageFunc(OnMessageFunc func)
{
m_MessageFunc = func;
}

另外在应用该类的时候发现了一个Websocket++的一个问题: 不能在Websocket连接完成之后马上就发送消息,不然会出现Invalid State的错误,导致消息发送不成功,所以在连接成功之后,主线程休眠1秒,这在代码中也有体现。