Package org.apache.commons.collections.buffer

Class UnboundedFifoBuffer

java.lang.Object
java.util.AbstractCollection
org.apache.commons.collections.buffer.UnboundedFifoBuffer
All Implemented Interfaces:
Serializable, Iterable, Collection, Buffer
@Deprecated(since="2021-04-30") public class UnboundedFifoBuffer extends AbstractCollection implements Buffer, Serializable
Deprecated.
Apache Commons Collections version 3.x is being deprecated from AEMaaCS. The upgraded version 4.4 of Commons Collections is already included as replacement. Customers are advised to upgrade to this version of the library. Please note: the package name was changed to org.apache.commons.collections4. Further note that there are AEM APIs currently exposing the old collections classes; these will be updated in upcoming releases.
UnboundedFifoBuffer is a very efficient implementation of Buffer that can grow to any size. According to performance testing, it exhibits a constant access time, but it also outperforms ArrayList when used for the same purpose.

The removal order of an UnboundedFifoBuffer is based on the insertion order; elements are removed in the same order in which they were added. The iteration order is the same as the removal order.

The remove() and get() operations perform in constant time. The add(Object) operation performs in amortized constant time. All other operations perform in linear time or worse.

Note that this implementation is not synchronized. The following can be used to provide synchronized access to your UnboundedFifoBuffer: 

    Buffer fifo = BufferUtils.synchronizedBuffer(new UnboundedFifoBuffer());

This buffer prevents null objects from being added.

This class is Serializable from Commons Collections 3.1.

Since:
Commons Collections 3.0 (previously in main package v2.1)
See Also:

  • Constructor Details

    • UnboundedFifoBuffer

      public UnboundedFifoBuffer()
      Deprecated.
      Constructs an UnboundedFifoBuffer with the default number of elements. It is exactly the same as performing the following: 
         new UnboundedFifoBuffer(32);

    • UnboundedFifoBuffer

      public UnboundedFifoBuffer(int initialSize)
      Deprecated.
      Constructs an UnboundedFifoBuffer with the specified number of elements. The integer must be a positive integer.
      Parameters:
      initialSize - the initial size of the buffer
      Throws:
      IllegalArgumentException - if the size is less than 1

  • Method Details

    • size

      public int size()
      Deprecated.
      Returns the number of elements stored in the buffer.
      Specified by:
      size in interface Collection
      Specified by:
      size in class AbstractCollection
      Returns:
      this buffer's size

    • isEmpty

      public boolean isEmpty()
      Deprecated.
      Returns true if this buffer is empty; false otherwise.
      Specified by:
      isEmpty in interface Collection
      Overrides:
      isEmpty in class AbstractCollection
      Returns:
      true if this buffer is empty

    • add

      public boolean add(Object obj)
      Deprecated.
      Adds the given element to this buffer.
      Specified by:
      add in interface Collection
      Overrides:
      add in class AbstractCollection
      Parameters:
      obj - the element to add
      Returns:
      true, always
      Throws:
      NullPointerException - if the given element is null

    • get

      public Object get()
      Deprecated.
      Returns the next object in the buffer.
      Specified by:
      get in interface Buffer
      Returns:
      the next object in the buffer
      Throws:
      BufferUnderflowException - if this buffer is empty

    • remove

      public Object remove()
      Deprecated.
      Removes the next object from the buffer
      Specified by:
      remove in interface Buffer
      Returns:
      the removed object
      Throws:
      BufferUnderflowException - if this buffer is empty

    • iterator

      public Iterator iterator()
      Deprecated.
      Returns an iterator over this buffer's elements.
      Specified by:
      iterator in interface Collection
      Specified by:
      iterator in interface Iterable
      Specified by:
      iterator in class AbstractCollection
      Returns:
      an iterator over this buffer's elements