@Bean
    @ConditionalOnMissingBean(WebsocketDataChangedListener.class)
    public DataChangedListener websocketDataChangedListener() {
        return new WebsocketDataChangedListener();
    }
Config event listener data changed listener.

@return the data changed listener
shenyu-admin/src/main/java/org/apache/shenyu/admin/config/WebSocketSyncConfiguration.java