Package org.apache.commons.collections4.queue

Class UnmodifiableQueue<E>

  • Type Parameters:
    E - the type of elements held in this queue
    All Implemented Interfaces:
    java.io.Serializable, java.lang.Iterable<E>, java.util.Collection<E>, java.util.Queue<E>, Unmodifiable
    public final class UnmodifiableQueue<E>
extends AbstractQueueDecorator<E>
implements Unmodifiable
    Decorates another Queue to ensure it can't be altered.

    Attempts to modify it will result in an UnsupportedOperationException.

    Since:
    4.0
    See Also:
    Serialized Form

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean add​(java.lang.Object object)  
      boolean addAll​(java.util.Collection<? extends E> coll)  
      void clear()  
      java.util.Iterator<E> iterator()  
      boolean offer​(E obj)  
      E poll()  
      E remove()  
      boolean remove​(java.lang.Object object)  
      boolean removeAll​(java.util.Collection<?> coll)  
      boolean removeIf​(java.util.function.Predicate<? super E> filter)  
      boolean retainAll​(java.util.Collection<?> coll)  
      static <E> java.util.Queue<E> unmodifiableQueue​(java.util.Queue<? extends E> queue)
      Factory method to create an unmodifiable queue.

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

      • Methods inherited from interface java.util.Collection

        contains, containsAll, equals, hashCode, isEmpty, parallelStream, size, spliterator, stream, toArray, toArray, toArray

      • Methods inherited from interface java.lang.Iterable

        forEach

    • Method Detail

      • unmodifiableQueue

        public static <E> java.util.Queue<E> unmodifiableQueue​(java.util.Queue<? extends E> queue)
        Factory method to create an unmodifiable queue.

        If the queue passed in is already unmodifiable, it is returned.

        Type Parameters:
        E - the type of the elements in the queue
        Parameters:
        queue - the queue to decorate, must not be null
        Returns:
        an unmodifiable Queue
        Throws:
        java.lang.NullPointerException - if queue is null

      • iterator

        public java.util.Iterator<E> iterator()
        Specified by:
        iterator in interface java.util.Collection<E>
        Specified by:
        iterator in interface java.lang.Iterable<E>
        Overrides:
        iterator in class AbstractCollectionDecorator<E>

      • add

        public boolean add​(java.lang.Object object)
        Specified by:
        add in interface java.util.Collection<E>
        Specified by:
        add in interface java.util.Queue<E>
        Overrides:
        add in class AbstractCollectionDecorator<E>

      • addAll

        public boolean addAll​(java.util.Collection<? extends E> coll)
        Specified by:
        addAll in interface java.util.Collection<E>
        Overrides:
        addAll in class AbstractCollectionDecorator<E>

      • remove

        public boolean remove​(java.lang.Object object)
        Specified by:
        remove in interface java.util.Collection<E>
        Overrides:
        remove in class AbstractCollectionDecorator<E>

      • removeIf

        public boolean removeIf​(java.util.function.Predicate<? super E> filter)
        Specified by:
        removeIf in interface java.util.Collection<E>
        Overrides:
        removeIf in class AbstractCollectionDecorator<E>
        Since:
        4.4

      • removeAll

        public boolean removeAll​(java.util.Collection<?> coll)
        Specified by:
        removeAll in interface java.util.Collection<E>
        Overrides:
        removeAll in class AbstractCollectionDecorator<E>

      • retainAll

        public boolean retainAll​(java.util.Collection<?> coll)
        Specified by:
        retainAll in interface java.util.Collection<E>
        Overrides:
        retainAll in class AbstractCollectionDecorator<E>