Spring, why don't we use synchronize?

Question

Java

How does multithreading work in a Spring application? It uses servlets, a thread is created per user, so why don't errors occur?
Without a framework, we have to synchronize methods, but here we call methods of other classes from the controller without synchronize, why doesn’t the code break?
Silly question, I know, but I would be very grateful for the answer.

Answer 1

Multithreading works exactly the same.
synchronized is used whether you use any frameworks or not.
Multithreaded applications can be written without any locks at all, resolving access to resources by architectural decisions, using immutable types, etc.