Since Java 9 the methods requireNonNullElse and requireNonNullElseGet are part of the java.util.Objects class.
The method requireNonNullElse accepts two arguments.
The first argument is an object that will be returned if that object is not null.
The second argument is an object to be returned when the first argument is null.
With this method you can replace the following ternary operator if (a != null) ? a : b (or if (a == null) ? b : a) with Objects.requireNonNullElse(a, b).
The method requireNonNullElseGet allows to define a Supplier function as second argument.
The Supplier is only invoked when the first argument is null, so it is lazy and will only be invoked when the first argument is null.
