When dealing with tokens please note that there are many things to consider some of which you have already mentioned
- Refreshing the token - you can create a scheduled task to fetch the token, maybe use service caching ?
- Where do you want to store it- you have mentioned that it is a properties file- you may need to consider the security risks here.
- How can you pass it to a service - Global variables , read files?
- What happens if the token has actually expired/ is an invalid token? - would you regenerate the token?
A good discussion on a similar topic of storing /refreshing tokens is at Integration Server handling JWT third party (consumer service) - Forum - webMethods - Software AG Tech Community & Forums
That being said, the ultimate decision would depend on your requirements. Looking forward for an interesting discussion on this.
-NP