Java set persistent environment variable

Question

I have set environment varible through

System.setProperty("mykey" : "itsvalue");

I am retrieving it as :

System.getProperty("mykey");

I get the mykey retrieved properly, but when I restart my service, mykey also get erased. How to save the mykey so that it remains persistent even after service restart?

I don't want to save it in database or cache.

Answer 1

If you just store key value pairs java already has api for this purpose.

You can use preferences API to store key value pairs.

https://www.javaworld.com/article/2071328/the-preferences-api.html

If you have lot of entries better use Database.