用QWebSocketServer写websocket服务端

1. 引入必要的头文件

#include <QCoreApplication>
#include <QWebSocketServer>
#include <QWebSocket>
#include <QDebug>
#include <QObject>

• QCoreApplication：用于创建控制台应用的事件循环。
• QWebSocketServer：提供 WebSocket 服务端的接口，用于监听和管理客户端连接。
• QWebSocket：表示每个客户端连接的 WebSocket 通道。
• QDebug：用于输出调试信息。
• QObject：所有 Qt 对象的基类，提供信号和槽机制。

2. 定义 WebSocketServer 类 

class WebSocketServer : public QObject
{Q_OBJECTpublic:WebSocketServer(quint16 port, QObject *parent = nullptr);~WebSocketServer();private slots:void onNewConnection();void onTextMessageReceived(const QString &message);void onClientDisconnected();void onClosed();private:QWebSocketServer *m_server;QList<QWebSocket *> m_clients;
};

• WebSocketServer 类：自定义的 WebSocket 服务端类，继承自 QObject。
• 构造函数：接受一个端口号，创建并启动 WebSocket 服务端。
• 析构函数：关闭服务端并清理所有客户端连接。
• 槽函数：用于处理新连接、接收消息、客户端断开连接、和服务端关闭的事件。
• 私有成员变量：
  • m_server：QWebSocketServer 对象，用于监听和处理客户端连接。
  • m_clients：存储所有连接的客户端。

3. 构造函数和析构函数 

WebSocketServer::WebSocketServer(quint16 port, QObject *parent): QObject(parent), m_server(new QWebSocketServer(QStringLiteral("Echo Server"),QWebSocketServer::NonSecureMode, this))
{if (m_server->listen(QHostAddress::Any, port)) {qDebug() << "WebSocket server listening on port" << port;connect(m_server, &QWebSocketServer::newConnection, this, &WebSocketServer::onNewConnection);connect(m_server, &QWebSocketServer::closed, this, &WebSocketServer::onClosed);}
}WebSocketServer::~WebSocketServer() {m_server->close();qDeleteAll(m_clients.begin(), m_clients.end());
}

• 构造函数：启动服务端监听指定的端口，并连接 newConnection 信号（处理新客户端连接）和 closed 信号（处理服务端关闭）。
• 析构函数：关闭服务端并清理所有客户端连接，以确保内存不会泄漏。

4. 处理新客户端连接

void WebSocketServer::onNewConnection() {QWebSocket *client = m_server->nextPendingConnection();connect(client, &QWebSocket::textMessageReceived, this, &WebSocketServer::onTextMessageReceived);connect(client, &QWebSocket::disconnected, this, &WebSocketServer::onClientDisconnected);m_clients << client;qDebug() << "New client connected";
}

 onNewConnection：在 newConnection 信号触发时调用，处理新的客户端连接。

• 获取新连接的 QWebSocket 对象。
• 将新客户端的 textMessageReceived 信号连接到 onTextMessageReceived 槽函数，用于处理客户端发送的消息。
• 将 disconnected 信号连接到 onClientDisconnected 槽函数，用于清理断开的客户端。
• 将新连接添加到客户端列表 m_clients 中，方便后续管理。

5. 处理客户端消息 

void WebSocketServer::onTextMessageReceived(const QString &message) {QWebSocket *senderClient = qobject_cast<QWebSocket *>(sender());if (senderClient) {qDebug() << "Message received:" << message;senderClient->sendTextMessage("Echo: " + message);}
}

onTextMessageReceived：当客户端发送文本消息时被调用。

• sender() 获取发送该信号的客户端对象，将其转换为 QWebSocket 类型。
• 输出接收到的消息，并将其回显给客户端。

 6. 处理客户端断开连接

void WebSocketServer::onClientDisconnected() {QWebSocket *client = qobject_cast<QWebSocket *>(sender());if (client) {m_clients.removeAll(client);client->deleteLater();qDebug() << "Client disconnected";}
}

onClientDisconnected：在客户端断开连接时调用。

• 获取断开连接的客户端对象，将其从 m_clients 列表中移除。
• 调用 deleteLater() 延迟删除对象，释放其内存。

7. 处理服务端关闭 

void WebSocketServer::onClosed() {qDebug() << "Server closed";
}

 整体代码

 

#include <QCoreApplication>
#include <QWebSocketServer>
#include <QWebSocket>
#include <QDebug>
#include <QObject>class WebSocketServer : public QObject
{Q_OBJECTpublic:WebSocketServer(quint16 port, QObject *parent = nullptr) : QObject(parent), m_server(new QWebSocketServer(QStringLiteral("Echo Server"),QWebSocketServer::NonSecureMode, this)){if (m_server->listen(QHostAddress::Any, port)) {qDebug() << "WebSocket server listening on port" << port;connect(m_server, &QWebSocketServer::newConnection, this, &WebSocketServer::onNewConnection);connect(m_server, &QWebSocketServer::closed, this, &WebSocketServer::onClosed);}}~WebSocketServer() {m_server->close();qDeleteAll(m_clients.begin(), m_clients.end());}private slots:void onNewConnection() {QWebSocket *client = m_server->nextPendingConnection();connect(client, &QWebSocket::textMessageReceived, this, &WebSocketServer::onTextMessageReceived);connect(client, &QWebSocket::disconnected, this, &WebSocketServer::onClientDisconnected);m_clients << client;qDebug() << "New client connected";}void onTextMessageReceived(const QString &message) {QWebSocket *senderClient = qobject_cast<QWebSocket *>(sender());if (senderClient) {qDebug() << "Message received:" << message;senderClient->sendTextMessage("Echo: " + message);}}void onClientDisconnected() {QWebSocket *client = qobject_cast<QWebSocket *>(sender());if (client) {m_clients.removeAll(client);client->deleteLater();qDebug() << "Client disconnected";}}void onClosed() {qDebug() << "Server closed";}private:QWebSocketServer *m_server;QList<QWebSocket *> m_clients;
};int main(int argc, char *argv[]) {QCoreApplication a(argc, argv);WebSocketServer server(9000);return a.exec();
}