[Fix] Make WebSocket ServerEndpointExporter conditional to avoid ServerContainer not available

[zhang-arvin]

What changes were proposed in this pull request

Make the WebSocket ServerEndpointExporter bean conditional on the websocket.enabled property (default: true), so that the application can start gracefully when the javax.websocket.server.ServerContainer is not available.

Why are the changes needed?

When flink-shaded-hadoop-3-uber jar is placed in the lib/ directory, it conflicts with the embedded server's WebSocket implementation, causing the ServerContainer to be unavailable. This results in the application failing to start with:

java.lang.IllegalStateException: javax.websocket.server.ServerContainer not available

This fix makes the WebSocket support optional, allowing users to disable WebSocket by setting websocket.enabled=false when they encounter classpath conflicts.

Fix: #3907

How was this patch tested?

• Manual verification: The @ConditionalOnProperty annotation is a standard Spring Boot mechanism that is widely used in the project.
• The existing behavior is preserved: when websocket.enabled is not set (or set to true), the ServerEndpointExporter bean is created as before.
• When websocket.enabled=false, the bean is not created, and the application starts without WebSocket support. The MessageServiceImpl.push() method already handles the case where WebSocket is unavailable via try-catch.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud