WebSocket 会话中对象的处理

Question

我正在尝试在 Java 中构建一个 WebSocket 服务器，并与一个简单的 javascript WebSocketClient 连接。现在我想 "give" 每个传入的会话都是一个对象的唯一实例，该对象在 onopen 上创建，它们的方法在 onmessage 上调用并在 onclose 上销毁。我如何管理这些对象？有没有办法将它存储在会话中？或者服务器本身是否处理这些事情，我可以在 "Endpoint class"?

中定义一个私有变量

package com.xxx.server;

import java.io.BufferedReader;
import java.io.InputStreamReader;

import org.glassfish.tyrus.server.Server;

public class TestWebSocketServer {
    public static void main(String[] args) {
        runServer();
    }

    public static void runServer() {
        Server server = new Server("localhost", 21212, "/xxx", TestServerEndpoint.class);

        try {
            server.start();
            BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
            System.out.print("Please press a key to stop the server.");
            reader.readLine();
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            server.stop();
        }
    }
}

package com.xxx.server;

import java.io.IOException;
import java.util.logging.Logger;

import javax.websocket.CloseReason;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.CloseReason.CloseCodes;
import javax.websocket.server.ServerEndpoint;

@ServerEndpoint(value = "/TEST")
public class TestServerEndpoint {

    private Logger logger = Logger.getLogger(this.getClass().getName());

    @OnOpen
    public void onOpen(Session session) {
        logger.info("Connected ... " + session.getId());
    }

    @OnMessage
    public String onMessage(String message, Session session) {
        switch (message) {
        case "quit":
            try {
                session.close(new CloseReason(CloseCodes.NORMAL_CLOSURE, "Test ended"));
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
            break;
        }
        return message;
    }

    @OnClose
    public void onClose(Session session, CloseReason closeReason) {
        logger.info(String.format("Session %s closed because of %s", session.getId(), closeReason));
    }
}

Answer 1

您不需要自己处理这些对象，Java EE 服务器会处理它。您只需要在端点 class 中创建一个实例变量。例如，

@ServerEndpoint(value = "/test-server/")
public class TestWebSocketServer {
  private YourObject yourObject = new YourObject();
  //or instantiate it in constructor    
}

只要您打开与服务器的新 websocket 连接，JavaEE 服务器就会创建一个新的 yourObject，并会在您关闭连接时为垃圾收集做好准备。

WebSocket 会话中对象的处理

Handling of Objects in WebSocket Session

java

session

glassfish

websocket