Spring: Singleton/session scopes and concurrency

Question

Does singleton/session scopes of Spring beans require that access to all its fields must be synchronized? Say through \"synchronized\" keyword or using some classes from package

Answer 1

Basically for every user that initiates a session a new ShoppingCart will be created and scoped to that session per that user.

Your class is thread-safe. The initialization

private List items = new ArrayList();

is a thread-safe initialization and

addItem(Product item) is an atomic operation and is also therefore thread-safe.