How to capture com.solacesystems.jcsmp.JCSMPErrorResponseException: 503

Ok... so you're shutting down the VPN to simulate a network outage? That's cool. The API will automatically attempt to reconnect for the amount of times specified in your JCSMPChannelProperties. By default, only once all reconnect attempts have failed will a (transport) exception be thrown up to the application to signal there was a failure.

But if the application wants to be notified of disconnect/reconnect events (e.g. to set a GUI element or something), then you gotta implement the JCSMPReconnectEventHandler when you create the Consumer object: https://docs.solace.com/API-Developer-Online-Ref-Documentation/java/com/solacesystems/jcsmp/JCSMPSession.html#getMessageConsumer(com.solacesystems.jcsmp.JCSMPReconnectEventHandler, com.solacesystems.jcsmp.XMLMessageListener)

Hope that helps!

Ok... first off... I misread/misunderstood your original question... you were looking to find how to capture the more detailed log/reason information in your exception, correct? Not just have your application be aware of connection issues? If the former, I don't think you can get the exact reason in the exception.

Anyhow... if it was the latter... in JMS, the JMS specification doesn't explicitly provide any mechanism to "listen" to disconnect/reconnect events. Only once your connection retry attempts are exhausted does the API throw a JMSException up to the applicaiton. Usually.

But in Solace, there is a way for a JMS app to hook up to these notification events... check out: https://docs.solace.com/Solace-JMS-API/Managing-Sessions.htm#Handling

It is possible to register an SolConnectionEventListener to receive callbacks whenever the connection state transitions. Here is an sample snippet:

SolConnectionEventSource eventSource = (SolConnectionEventSource) jmsConnection;
eventSource.setConnectionEventListener(new SolConnectionEventListener() {

@Override
public void onEvent(SolConnectionEvent event) {
System.out.println(event.getType());
}});

Javadocs can be found at:
https://docs.solace.com/API-Developer-Online-Ref-Documentation/jms/index.html
You will need to search for SolConnectionEventListener.