EndpointEventListener (Tyrus 2.1.4 API)

```
@Beta
public interface EndpointEventListener
```
Listens to endpoint-level events that are interesting for monitoring.

Author:

Petr Janouch

Field Summary

Fields
Modifier and Type Field Description

static EndpointEventListener NO_OP
An instance of @EndpointEventListener that does not do anything.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`onError(java.lang.String sessionId, java.lang.Throwable t)`	Called when an error has occurred.
`void`	`onSessionClosed(java.lang.String sessionId)`	Called when a session has been closed.
`MessageEventListener`	`onSessionOpened(java.lang.String sessionId)`	Called when a session has been opened.

- Field Detail
  - NO_OP
```
static final EndpointEventListener NO_OP
```
    An instance of @EndpointEventListener that does not do anything.
- Method Detail
  - onSessionOpened
```
MessageEventListener onSessionOpened(java.lang.String sessionId)
```
    Called when a session has been opened.
    
    Parameters:
    
    sessionId - an ID of the newly opened session.
    
    Returns:
    
    listener that listens for message-level events.
  - onSessionClosed
```
void onSessionClosed(java.lang.String sessionId)
```
    Called when a session has been closed.
    
    Parameters:
    
    sessionId - an ID of the closed session.
  - onError
```
void onError(java.lang.String sessionId,
             java.lang.Throwable t)
```
    Called when an error has occurred.
    Errors that occur either during Endpoint.onOpen(jakarta.websocket.Session, jakarta.websocket.EndpointConfig), Endpoint.onClose(jakarta.websocket.Session, jakarta.websocket.CloseReason) and their annotated equivalent or when handling an incoming message, cause this listener to be called. It corresponds to the event of invocation of (jakarta.websocket.Session, Throwable) and its annotated equivalent.
    
    Parameters:
    
    sessionId - an ID of the session on which the error occurred.
    
    t - throwable that has been thrown.