UnmodifiableLists

package functional;

import java.util.Collections;
import java.util.List;

public class UnmodifiableLists {

    public static void main(String[] args) {
        List<String> modifiableList = List.of("A", "B", "C");
        modifiableList.add("D"); //UnsupportedOperationException
        List<String> unmodifiableList = Collections.unmodifiableList(modifiableList);
        unmodifiableList.add("D"); // UnsupportedOperationException
        modifiableList.add("D"); //UnsupportedOperationException
    }
}