J2EE/Quarkus/Undertow - 处理复制之间的WebSocket会话

下面是一个使用J2EE、Quarkus和Undertow处理WebSocket会话复制的示例代码：

首先，你需要创建一个WebSocket端点类，用于处理客户端连接和消息：

import javax.enterprise.context.ApplicationScoped;
import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;

@ApplicationScoped
@ServerEndpoint("/websocket")
public class WebSocketEndpoint {

    @OnOpen
    public void onOpen(Session session) {
        // 处理新的客户端连接
        // ...
    }

    @OnMessage
    public void onMessage(String message, Session session) {
        // 处理客户端发送的消息
        // ...
    }

    @OnClose
    public void onClose(Session session) {
        // 处理客户端断开连接
        // ...
    }

    @OnError
    public void onError(Session session, Throwable error) {
        // 处理错误
        // ...
    }
}

接下来，你需要创建一个WebSocket拦截器，用于在会话复制时处理WebSocket会话的跟踪：

import io.undertow.servlet.api.Session;
import io.undertow.servlet.spec.HttpSessionImpl;
import io.undertow.servlet.spec.WebSocketHttpSessionFacade;
import io.quarkus.runtime.annotations.RegisterForReflection;
import io.quarkus.undertow.runtime.UndertowWebSocketSession;

import javax.enterprise.event.Event;
import javax.inject.Inject;
import javax.servlet.http.HttpSession;
import javax.websocket.*;

@RegisterForReflection // 注册类以便在运行时进行反射
@ClientEndpoint
public class WebSocketReplicationInterceptor {

    @Inject
    Event<WebSocketSessionEvent> webSocketSessionEvent;

    @OnOpen
    public void onOpen(Session session) {
        // 将WebSocket会话存储在HTTP会话中
        HttpSession httpSession = getSession(session);
        httpSession.setAttribute("WebSocketSession", session);

        // 发布WebSocket会话事件
        webSocketSessionEvent.fire(new WebSocketSessionEvent(session, WebSocketSessionEvent.Type.OPEN));
    }

    @OnMessage
    public void onMessage(String message, Session session) {
        // 处理客户端发送的消息
        // ...
    }

    @OnClose
    public void onClose(Session session, CloseReason closeReason) {
        // 从HTTP会话中删除WebSocket会话
        HttpSession httpSession = getSession(session);
        httpSession.removeAttribute("WebSocketSession");

        // 发布WebSocket会话事件
        webSocketSessionEvent.fire(new WebSocketSessionEvent(session, WebSocketSessionEvent.Type.CLOSE));
    }

    @OnError
    public void onError(Session session, Throwable error) {
        // 处理错误
        // ...
    }

    private HttpSession getSession(Session session) {
        if (session instanceof UndertowWebSocketSession) {
            UndertowWebSocketSession undertowSession = (UndertowWebSocketSession) session;
            WebSocketHttpSessionFacade sessionFacade = (WebSocketHttpSessionFacade) undertowSession.getHttpSession();
            return sessionFacade.getUndertowSession().getDeployment().getSession(sessionFacade.getUndertowSession().getSessionId());
        } else {
            throw new IllegalStateException("Unsupported WebSocketSession implementation: " + session.getClass().getName());
        }
    }
}

最后，你需要注册WebSocket端点和拦截器：

import io.quarkus.runtime.StartupEvent;

import javax.enterprise.context.ApplicationScoped;
import javax.enterprise.event.Observes;
import javax.websocket.DeploymentException;
import javax.websocket.server.ServerContainer;
import javax.websocket.server.ServerEndpointConfig;

@ApplicationScoped
public class WebSocketConfig {

    void onStart(@Observes StartupEvent ev, ServerContainer serverContainer) throws DeploymentException {
        // 注册WebSocket端点
        ServerEndpointConfig.Builder endpointConfigBuilder = ServerEndpointConfig.Builder.create(WebSocketEndpoint.class, "/websocket");
        ServerEndpointConfig endpointConfig = endpointConfigBuilder.build();
        serverContainer.addEndpoint(endpointConfig);

        // 注册WebSocket拦截器
        serverContainer.addEndpoint(WebSocketReplicationInterceptor.class);
    }
}

这样，你就可以使用J2EE、Quarkus和Undertow处理WebSocket会话复制了。