How can real-time message push functionality be implemented in Java?

To achieve real-time message pushing in Java, you can use WebSocket technology. Here is a simple implementation process:

1. In Java, you can create a WebSocket server using the WebSocket API, for example, by using Java WebSocket libraries like Tyrus or Jetty.
2. Create a WebSocket endpoint class on the server side to handle WebSocket connections and message sending. You can create a WebSocket endpoint by inheriting from the javax.websocket.Endpoint class.
3. In the WebSocket endpoint class, implement methods such as onOpen, onMessage, onClose, and onError to handle events like WebSocket connection opening, message receiving, closing, and errors.
4. In the onOpen method, you can store the connected session object for future use.
5. In the onMessage method, you can process the received message content accordingly and send real-time messages to the client.
6. On the client side, create a WebSocket object using the WebSocket API in JavaScript to connect to the server.
7. Listen for real-time messages sent from the server by using the WebSocket object’s onmessage event in the client-side.
8. Messages can also be sent to the server from the client side using the send method of the WebSocket object.

By following the above steps, you can achieve real-time message pushing functionality in Java. When there is a new message on the server side, it will be sent in real-time to connected clients.