How to dynamically add Predicate into List

Question

Is there any way to dynamically add Predicate into List in Java? For a brief illustration I've done it like this:

List<Predicate<String>> filters = Arrays.asList(
    t -> !Utilities.isNumeric(t)
);
filters.add(t -> !t.isEmpty());

But executing the filters.add results in UnsupportedOperationException. Fixed List like this is fine tho.

List<Predicate<String>> filters = Arrays.asList(
    t -> !Utilities.isNumeric(t),
    t -> !t.isEmpty()
);

Answer 1

Solution:

List<Predicate<String>> filters = new ArrayList<>(Arrays.asList(
    t -> !Utilities.isNumeric(t)
));

Explanation:

Arrays.asList returns a fixed-length list¹ wrapper for the array argument. Since it is fixed sized, methods that would change the size throw UnsupportedOperationException.

By feeding this to the ArrayList constructor, you create a new list, whose size can be changed.

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^{1 - .... but the list is NOT immutable. It can be modified by updating the backing array, or by using the List::set(int, T) method.}