Package org.apache.commons.collections4.collection

Class PredicatedCollection.Builder<E>

java.lang.Object
org.apache.commons.collections4.collection.PredicatedCollection.Builder<E>
Type Parameters:
E - the element type
Enclosing class:
PredicatedCollection<E>
public static class PredicatedCollection.Builder<E> extends Object
Builder for creating predicated collections.

Create a Builder with a predicate to validate elements against, then add any elements to the builder. Elements that fail the predicate will be added to a rejected list. Finally, create or decorate a collection using the createPredicated[List,Set,Bag,Queue] methods.

An example: 

   Predicate<String> predicate = NotNullPredicate.notNullPredicate();
   PredicatedCollectionBuilder<String> builder = PredicatedCollection.builder(predicate);
   builder.add("item1");
   builder.add(null);
   builder.add("item2");
   List<String> predicatedList = builder.createPredicatedList();

At the end of the code fragment above predicatedList is protected by the predicate supplied to the builder, and it contains item1 and item2.

More elements can be added to the builder once a predicated collection has been created, but these elements will not be reflected in already created collections.

Since:
4.1

  • Constructor Details

    • Builder

      public Builder(Predicate<? super E> predicate)
      Constructs a PredicatedCollectionBuilder with the specified Predicate.
      Parameters:
      predicate - the predicate to use
      Throws:
      NullPointerException - if predicate is null

  • Method Details

    • add

      public PredicatedCollection.Builder<E> add(E item)
      Adds the item to the builder.

      If the predicate is true, it is added to the list of accepted elements, otherwise it is added to the rejected list.

      Parameters:
      item - the element to add
      Returns:
      the PredicatedCollectionBuilder.

    • addAll

      public PredicatedCollection.Builder<E> addAll(Collection<? extends E> items)
      Adds all elements from the given collection to the builder.

      All elements for which the predicate evaluates to true will be added to the list of accepted elements, otherwise they are added to the rejected list.

      Parameters:
      items - the elements to add to the builder
      Returns:
      the PredicatedCollectionBuilder.

    • createPredicatedBag

      public Bag<E> createPredicatedBag()
      Create a new predicated bag filled with the accepted elements.

      The builder is not modified by this method, so it is possible to create more collections or add more elements afterwards. Further changes will not propagate to the returned bag.

      Returns:
      a new predicated bag.

    • createPredicatedBag

      public Bag<E> createPredicatedBag(Bag<E> bag)
      Decorates the given bag with validating behavior using the predicate. All accepted elements are appended to the bag. If the bag already contains elements, they are validated.

      The builder is not modified by this method, so it is possible to create more collections or add more elements afterwards. Further changes will not propagate to the returned bag.

      Parameters:
      bag - the bag to decorate, must not be null
      Returns:
      the decorated bag.
      Throws:
      NullPointerException - if bag is null
      IllegalArgumentException - if bag contains invalid elements

    • createPredicatedList

      public List<E> createPredicatedList()
      Create a new predicated list filled with the accepted elements.

      The builder is not modified by this method, so it is possible to create more collections or add more elements afterwards. Further changes will not propagate to the returned list.

      Returns:
      a new predicated list.

    • createPredicatedList

      public List<E> createPredicatedList(List<E> list)
      Decorates the given list with validating behavior using the predicate. All accepted elements are appended to the list. If the list already contains elements, they are validated.

      The builder is not modified by this method, so it is possible to create more collections or add more elements afterwards. Further changes will not propagate to the returned list.

      Parameters:
      list - the List to decorate, must not be null
      Returns:
      the decorated list.
      Throws:
      NullPointerException - if list is null
      IllegalArgumentException - if list contains invalid elements

    • createPredicatedMultiSet

      public MultiSet<E> createPredicatedMultiSet()
      Create a new predicated multiset filled with the accepted elements.

      The builder is not modified by this method, so it is possible to create more collections or add more elements afterwards. Further changes will not propagate to the returned multiset.

      Returns:
      a new predicated multiset.

    • createPredicatedMultiSet

      public MultiSet<E> createPredicatedMultiSet(MultiSet<E> multiset)
      Decorates the given multiset with validating behavior using the predicate. All accepted elements are appended to the multiset. If the multiset already contains elements, they are validated.

      The builder is not modified by this method, so it is possible to create more collections or add more elements afterwards. Further changes will not propagate to the returned multiset.

      Parameters:
      multiset - the multiset to decorate, must not be null
      Returns:
      the decorated multiset.
      Throws:
      NullPointerException - if multiset is null
      IllegalArgumentException - if multiset contains invalid elements

    • createPredicatedQueue

      public Queue<E> createPredicatedQueue()
      Create a new predicated queue filled with the accepted elements.

      The builder is not modified by this method, so it is possible to create more collections or add more elements afterwards. Further changes will not propagate to the returned queue.

      Returns:
      a new predicated queue.

    • createPredicatedQueue

      public Queue<E> createPredicatedQueue(Queue<E> queue)
      Decorates the given queue with validating behavior using the predicate. All accepted elements are appended to the queue. If the queue already contains elements, they are validated.

      The builder is not modified by this method, so it is possible to create more collections or add more elements afterwards. Further changes will not propagate to the returned queue.

      Parameters:
      queue - the queue to decorate, must not be null
      Returns:
      the decorated queue.
      Throws:
      NullPointerException - if queue is null
      IllegalArgumentException - if queue contains invalid elements

    • createPredicatedSet

      public Set<E> createPredicatedSet()
      Create a new predicated set filled with the accepted elements.

      The builder is not modified by this method, so it is possible to create more collections or add more elements afterwards. Further changes will not propagate to the returned set.

      Returns:
      a new predicated set.

    • createPredicatedSet

      public Set<E> createPredicatedSet(Set<E> set)
      Decorates the given list with validating behavior using the predicate. All accepted elements are appended to the set. If the set already contains elements, they are validated.

      The builder is not modified by this method, so it is possible to create more collections or add more elements afterwards. Further changes will not propagate to the returned set.

      Parameters:
      set - the set to decorate, must not be null
      Returns:
      the decorated set.
      Throws:
      NullPointerException - if set is null
      IllegalArgumentException - if set contains invalid elements

    • rejectedElements

      public Collection<E> rejectedElements()
      Returns an unmodifiable collection containing all rejected elements.
      Returns:
      an unmodifiable collection