org.apache.commons.collections4.set

## Class PredicatedSet<E>

- java.lang.Object
- - org.apache.commons.collections4.collection.AbstractCollectionDecorator<E>
  - - org.apache.commons.collections4.collection.PredicatedCollection<E>
    - - org.apache.commons.collections4.set.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

- - ### Nested Class Summary

    - ### Nested classes/interfaces inherited from class org.apache.commons.collections4.collection.PredicatedCollection

      `PredicatedCollection.Builder<E>`

  - ### Field Summary

    - ### Fields inherited from class org.apache.commons.collections4.collection.PredicatedCollection

      `predicate`

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `protected` | `PredicatedSet(Set<E> set, Predicate<? super E> predicate)` Constructor that wraps (not copies).

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `protected Set<E>` | `decorated()` Gets the set being decorated.
    `boolean` | `equals(Object object)`
    `int` | `hashCode()`
    `static <E> PredicatedSet<E>` | `predicatedSet(Set<E> set, Predicate<? super E> predicate)` Factory method to create a predicated (validating) set.

    - ### Methods inherited from class org.apache.commons.collections4.collection.PredicatedCollection

      `add, addAll, builder, notNullBuilder, predicatedCollection, validate`

    - ### Methods inherited from class org.apache.commons.collections4.collection.AbstractCollectionDecorator

      `clear, contains, containsAll, isEmpty, iterator, remove, removeAll, removeIf, retainAll, setCollection, size, toArray, toArray, toString`

    - ### Methods inherited from class java.lang.Object

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

    - ### Methods inherited from interface java.util.Set

      `add, addAll, clear, contains, containsAll, isEmpty, iterator, remove, removeAll, retainAll, size, spliterator, toArray, toArray`

    - ### Methods inherited from interface java.util.Collection

      `parallelStream, removeIf, stream`

    - ### Methods inherited from interface java.lang.Iterable

      `forEach`

- - ### 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

    - #### decorated

          protected Set<E> decorated()

      Gets the set being decorated.
      Overrides:
        `decorated` in class `AbstractCollectionDecorator<E>`
      Returns:
        the decorated set

    - #### equals

          public boolean equals(Object object)

      Specified by:
        `equals` in interface `Collection<E>`
      Specified by:
        `equals` in interface `Set<E>`
      Overrides:
        `equals` in class `Object`

    - #### hashCode

          public int hashCode()

      Specified by:
        `hashCode` in interface `Collection<E>`
      Specified by:
        `hashCode` in interface `Set<E>`
      Overrides:
        `hashCode` in class `Object`

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