How do pools work in java?

Question

Java

Please tell me what pools exist in java and how they work. If possible, then the article is good, it is possible in a foreign language. There is a lot of information about String pools, but I did not find the rest.
I will be grateful for any useful information.

Answer 1

Strange question)
The pool can be made for any object. In java, there is at least a Thread pool, more precisely, it can be created, unlike the String pool, which is in java by default.
If you are talking about connection pools, then there are a bunch of implementations.
Basically, I don't understand your question.