Package io.quarkus.websockets.next

Annotation Interface OnOpen

@Retention(RUNTIME)
@Target(METHOD)
@Experimental("This API is experimental and may change in the future")
public @interface OnOpen

WebSocket and WebSocketClient endpoint methods annotated with this annotation are invoked when a new connection is opened. An endpoint may declare at most one method annotated with this annotation.

Execution model

• Methods annotated with RunOnVirtualThread are considered blocking and should be executed on a virtual thread.
• Methods annotated with Blocking are considered blocking and should be executed on a worker thread.
• Methods annotated with NonBlocking are considered non-blocking and should be executed on an event loop thread.

Execution model for methods which don't declare any of the annotation listed above is derived from the return type:

• Methods returning void are considered blocking and should be executed on a worker thread.
• Methods returning Uni or Multi are considered non-blocking and should be executed on an event loop thread.
• Methods returning any other type are considered blocking and should be executed on a worker thread.

Method parameters

The method may accept the following parameters:

• WebSocketConnection/WebSocketClientConnection; depending on the endpoint type
• HandshakeRequest
• String parameters annotated with PathParam

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element	Description
boolean	broadcast	Broadcasting is only supported for server endpoints annotated with WebSocket.

Element Details

broadcast

boolean broadcast

Broadcasting is only supported for server endpoints annotated with WebSocket.

Returns:

true if all the connected clients should receive the objects emitted by the annotated method

See Also:

• WebSocketConnection.broadcast()

Default:

false