websocketpp库使用非常方便，开源，可跨平台，内部实现全部是head文件，无cpp，接口简单易用。源码路径比如 https://github.com/zaphoyd/websocketpp.git
使用方法是，先下载源码包并复制道工程的include目录下。
--include
--websocketpp
然后在代码#include "utility_client.hpp"即可调用其接口进行websocket通信。以linux为例具体使用的方法代码示例：
websockettalker.h:
#ifndef WEBSOCKETTALKER_H
#define WEBSOCKETTALKER_H
#include "dao.h"
#include "utility_client.hpp"
#include "pthread.h"
#include "vector"using namespace std;
class CloudTalker;
class WebsocketTalker
{
public:WebsocketTalker(CloudTalker* talker, const string& remoteAddr, const string& name);~WebsocketTalker();string GetStatus();string GetMessage();bool Subscribe(const string& deviceId, const string& token);void handleNbData(const string& msg);private:CloudTalker* mTalker;static void* thread_loop(void* pVoid);pthread_t recv_thread;websocket_endpoint mEndpoint;int mId;string addr = "";bool should_exit = false;vector<DevInfo> mImeiTable;DAO* mDevDbDao = NULL;
};#endif // WEBSOCKETTALKER_Hwebsockettalker.cpp:
#include "websockettalker.h"
#include "cloudtalker.h"
#include "udptalker.h"
#include <boost/algorithm/string.hpp>using namespace boost;
#define JSON_PATH_DEV "path/to/devDB.json"
WebsocketTalker::WebsocketTalker(CloudTalker* talker, const string& remoteAddr, const string& name)
{string messageclient;addr = "ws://" + remoteAddr + ":8081/webSocketServer?" + name; //格式为cout <<"full address is:" <<addr <<endl;mTalker = talker;mDevDbDao = new DAO();pthread_create(&recv_thread, nullptr, thread_loop, this);
}/***********************************************************
* 描述: 处理数据
* 入参: wholeMsg - 要处理的数据
* 出参: 无
* 返回: 无
************************************************************/
void WebsocketTalker::handleData(const string& wholeMsg)
{cout <<endl;}/***********************************************************
* 描述: websocket通信线程
* 入参: pVoid - WebsocketTalker指针
* 出参: 无
* 返回: 无
************************************************************/
void* WebsocketTalker::thread_loop(void* pVoid)
{WebsocketTalker* p = (WebsocketTalker*) pVoid;string status = "";string wholeMsg = "";int cont = 0;unsigned int len = 0;while(!p->should_exit){p->mImeiTable.clear();printf("WEBSOCKET WANT TO CREATE CONNECT FOR NBIOT DATA\n");p->mDevDbDao->getNBAndShareImeiAll(JSON_PATH_DEV, p->mImeiTable);len = p->mImeiTable.size();if(len == 0){int cnt = 0;printf("nb/share dev list is zero\n");while(!p->should_exit && cnt++ <4){usleep(500000);}cnt = 0;continue;}p->mId = p->mEndpoint.connect(p->addr);if (p->mId == -1){cout << "Created connection failed! mId=" << p->mId<< endl;}else{while(!p->should_exit){usleep(50000);status = p->GetStatus();if(status.length() && status != "Connecting")break;}if(p->should_exit){printf("exit 1\n");break;}for(unsigned int i=0; i<len; i++){cout<<"subscribe dev: " << p->mImeiTable[i].IMEi<< "with token: "<<p->mImeiTable[i].Token<<endl;p->Subscribe(p->mImeiTable[i].IMEi, p->mImeiTable[i].Token);cont = 0;while(!p->should_exit){usleep(50000);status = p->GetStatus();if(status == "Message")break;if(cont++ > 40){printf("websocket data receive subscribe status timeout\n");//cont = 0;break;}}if(p->should_exit || cont > 40){printf("exit 2\n");break;}wholeMsg = p->GetMessage();printf("[%s(%d)%s] msg=%s\n", __FUNCTION__, __LINE__, __TIME__, wholeMsg.data());cont = 0;/*循环接收消息 */while(!p->should_exit){if(cont++ > 40){printf("websocket data receive timeout\n");//cont = 0;break;}status = p->GetStatus();//printf("get status: %s\n", status.c_str());if(status == "Message"){wholeMsg = p->GetMessage();printf("[%s(%d)%s;] GOT SUBSCRIBED DATA, msg=%s\n", __FUNCTION__, __LINE__, __TIME__, wholeMsg.data());p->handleNbData(wholeMsg);cont = 0;break;}usleep(50000);}if(p->should_exit){printf("exit 3\n");break;}}p->mEndpoint.close(p->mId, websocketpp::close::status::normal, "close");if(p->should_exit){printf("exit 3\n");break;}}usleep(2000000);//sleep long time could be.}return NULL;
}
string WebsocketTalker::GetStatus()
{return mEndpoint.get_metadata(mId)->get_status();
}string WebsocketTalker::GetMessage()
{return mEndpoint.get_metadata(mId)->get_message();
}bool WebsocketTalker::Subscribe(const string& deviceId, const string& token)
{string str;str = "{\"type\":\"address\",\"msg\":\"" + deviceId + "\",\"token\":\"" + token +"\"}";printf("[%s(%d)] %s\n", __FUNCTION__, __LINE__, str.data());mEndpoint.send(mId, str);return true;
}WebsocketTalker::~WebsocketTalker()
{printf("exit wstalker\n");if(mDevDbDao != NULL){delete mDevDbDao;}should_exit = true;pthread_join(recv_thread, NULL);printf("exit wstalker done\n");
}dao.h:
#ifndef DAO_H
#define DAO_H#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include "json/json.h"#ifndef UNUSED
#define UNUSED(x) (void)(x)
#endifusing namespace std;typedef struct
{string IMEi;string Type;string Token;
}DevInfo;class DAO{public:DAO(){}// 10. get device information transform to <vector> from json, "device information contain {IMEI, type, token, index}"int getNBAndShareImeiAll(const char* dfile_path, vector<DevInfo>& imeiTable){fstream dev_f;dev_f.open(dfile_path, ios::in | ios::out);if (!dev_f.is_open()){cout << "Open file error !" << endl;}Json::Value val;Json::Value root_arr;JSONCPP_STRING errs;//bool did;DevInfo devInfo;Json::CharReaderBuilder rbuilder;rbuilder["collectComments"] = false;bool parse_ok = Json::parseFromStream(rbuilder, dev_f, &root_arr, &errs);if(!parse_ok){cout << "Parse json file error !" << endl;}else{const Json::Value arrayObj = root_arr;cout << " ------ Printf Device information: ------ " << endl;try{for (unsigned int i = 0; i < arrayObj.size(); i++){if(arrayObj[i]["Type"].asString() == "LORA"){devInfo ={arrayObj[i]["IMEi"].asString(),arrayObj[i]["Type"].asString(),arrayObj[i]["Token"].asString()};imeiTable.push_back(devInfo);}}}catch (const Json::LogicError &ex){cout << " Parse json string error!" << endl;}}dev_f.close();return 0;}};#endif // DAO_HdevDB.json:
[{"IMEi" : "6789999","Token" : "jfkl","Type" : "LORA"},{"IMEi" : "00124b00","Token" : "0","Type" : "xxx"},]json的解析使用jsoncpp库，可自行安装。
)
)
)
