Package org.apache.commons.collections4.set

Class PredicatedSet<E>

  • Type Parameters:
    E - the type of the elements in this set
    All Implemented Interfaces:
    Serializable, Iterable<E>, Collection<E>, Set<E>
    Direct Known Subclasses:
    PredicatedSortedSet
    public class PredicatedSet<E>
extends PredicatedCollection<E>
implements Set<E>
    Decorates another Set to validate that all additions match a specified predicate.

    This set exists to provide validation for the decorated set. It is normally created to decorate an empty set. If an object cannot be added to the set, an IllegalArgumentException is thrown.

    One usage would be to ensure that no null entries are added to the set. 

    Set set = PredicatedSet.decorate(new HashSet(), NotNullPredicate.INSTANCE);

    This class is Serializable from Commons Collections 3.1.

    Since:
    3.0
    See Also:
    Serialized Form

    • Constructor Detail

      • PredicatedSet

        protected PredicatedSet​(Set<E> set,
                        Predicate<? super E> predicate)
        Constructor that wraps (not copies).

        If there are any elements already in the set being decorated, they are validated.

        Parameters:
        set - the set to decorate, must not be null
        predicate - the predicate to use for validation, must not be null
        Throws:
        NullPointerException - if set or predicate is null
        IllegalArgumentException - if the set contains invalid elements

    • Method Detail

      • predicatedSet

        public static <E> PredicatedSet<E> predicatedSet​(Set<E> set,
                                                 Predicate<? super E> predicate)
        Factory method to create a predicated (validating) set.

        If there are any elements already in the set being decorated, they are validated.

        Type Parameters:
        E - the element type
        Parameters:
        set - the set to decorate, must not be null
        predicate - the predicate to use for validation, must not be null
        Returns:
        a decorated set
        Throws:
        NullPointerException - if set or predicate is null
        IllegalArgumentException - if the set contains invalid elements
        Since:
        4.0