About Question enthuware.ocpjp.v11.2.3638 :

[darshanjoshi]

As AccessController.doPrivileged method is not returning void, so below code will not compile.

public void setApprovedUsers(final List<String> userids) {
return AccessController.doPrivileged((PrivilegedAction<Void>) () -> {
this.userManager.setApprovedUsers(userids);
return null;
});
}

[admin]

doPrivileged returns whatever PrivilegedAction's run method returns (given by the type of PrivilegedAction). Here, it returns Void because PrivilegedAction is typed to <Void>.
You may also check the example given here: https://docs.oracle.com/javase/8/docs/t ... leged.html

[minajev3]

Sorry but I am pretty sure your guess is wrong
because if we just pass unmodifiableList - user(customer) will still have control over it using his original list
but the main rule is not trust to users and dont allow them more than necessary.

[admin]

You are right. It should use List.of instead of Collections.unmodifiableList. Fixed.
thank you for your feedback!

[palmada]

While working on a code cleaup project fo

Small typo

[admin]

Fixed.
thank you for your feedback!

[driesva]

IMHO List.of(userids) is not correct, it creates a List of a List...

[admin]

You are right. It should be copyOf.