c++实现hvlib库websocket服务端和客户端

下面是使用 hvlib 库实现 WebSocket 服务端和客户端的 C++ 代码示例：

WebSocket 服务端：

#include "HttpServer.h"
#include "WebSocket.h"

using namespace hv;

class EchoWebSocketHandler : public WebSocketHandler {
public:
    virtual void onOpen(WebSocketChannel* channel) override {
        WebSocketHandler::onOpen(channel);
        printf("WebSocket onOpen: %s\n", channel->getPeerAddr().c_str());
    }

    virtual void onClose(WebSocketChannel* channel) override {
        WebSocketHandler::onClose(channel);
        printf("WebSocket onClose: %s\n", channel->getPeerAddr().c_str());
    }

    virtual void onMessage(WebSocketChannel* channel, const std::string& payload, bool isBinary) override {
        WebSocketHandler::onMessage(channel, payload, isBinary);
        printf("WebSocket onMessage: %s, isBinary=%d\n", payload.c_str(), isBinary);
        channel->send(payload, isBinary);
    }
};

int main() {
    HttpServer server;
    server.setReusePort(true);
    server.get("/hello", [](HttpRequest* req, HttpResponse* resp) {
        resp->body = "Hello, world!";
    });

    server.websocket("/echo", [](WebSocketChannel* channel) {
        channel->setHandler(new EchoWebSocketHandler);
    });

    server.listen("0.0.0.0", 8080);
    server.run();
    return 0;
}

WebSocket 客户端：

#include "WebSocketClient.h"

using namespace hv;

class EchoWebSocketClient : public WebSocketClient {
public:
    virtual void onOpen() override {
        WebSocketClient::onOpen();
        printf("WebSocket onOpen\n");
        send("Hello, WebSocket!", false);
    }

    virtual void onClose() override {
        WebSocketClient::onClose();
        printf("WebSocket onClose\n");
    }

    virtual void onMessage(const std::string& payload, bool isBinary) override {
        WebSocketClient::onMessage(payload, isBinary);
        printf("WebSocket onMessage: %s, isBinary=%d\n", payload.c_str(), isBinary);
        close();
    }
};

int main() {
    EventLoop loop;
    EchoWebSocketClient client;
    client.connect(&loop, "ws://127.0.0.1:8080/echo");
    loop.loop();
    return 0;
}

需要注意的是，在服务端使用 WebSocket 时，需要将连接升级为 WebSocket 连接，可以使用 `HttpServer` 类中的 `websocket` 方法来实现；在客户端使用 WebSocket 时，需要先建立连接，然后才能发送和接收消息。另外，需要注意正确处理 WebSocket 的生命周期事件，如 `onOpen`、`onClose`、`onMessage` 等。