I set a global variable in Extended settings, like vList=value01,value02,value03,value04. How could I retrieve value0x from this variable? Any build-in service could be helpful?

Don’t use the Extended settings for non-platform variables. Try using the Global Variables or request for WxConfig from SAG. Otherwise, use a properties files for your package etc.

Thanks for your advice. Anyway, if I insist to do it my own way, how could I implement it? In other words, How could I retrieve value0x from this variable? Any build-in service could be helpful?

For your case, you can use get server property service from WmPublic/pub/utils folder. Pass the key and then tokenize the value using comma.

However use global variable on IS if you are on wM 9.0 and above for using configuration values. Or use ehcache capabilities to store and retrieve key-value pairs by creating a custom cache manager and cache on IS and make use of OOTB cache services present in WmPublic package.

On the otherside WxConfig is not free and it requires a license for sag gcs team.

I believe using global variable value on IS with 9.x and above this feature will work only for each independent name value pair and not with setting with comma or some other delimiter.

As Mahesh pointed in the first option would work for you with key get value with tokenization (delim as comma)

HTH,
RMG