org.apache.lucene.util

## Class MergedIterator<T extends Comparable<T>>

- java.lang.Object
- - org.apache.lucene.util.MergedIterator<T>

- All Implemented Interfaces:
    Iterator<T>

      public final class MergedIterator<T extends Comparable<T>>
      extends Object
      implements Iterator<T>

  Provides a merged sorted view from several sorted iterators.

  If built with `removeDuplicates` set to true and an element appears in multiple iterators then it is deduplicated, that is this iterator returns the sorted union of elements.

  If built with `removeDuplicates` set to false then all elements in all iterators are returned.

  Caveats:

  - The behavior is undefined if the iterators are not actually sorted.
  - Null elements are unsupported.
  - If removeDuplicates is set to true and if a single iterator contains duplicates then they will not be deduplicated.
  - When elements are deduplicated it is not defined which one is returned.
  - If removeDuplicates is set to false then the order in which duplicates are returned isn't defined.
  NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `MergedIterator(boolean removeDuplicates, Iterator<T>... iterators)`
    `MergedIterator(Iterator<T>... iterators)`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `hasNext()`
    `T` | `next()`
    `void` | `remove()`

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

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

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

      `forEachRemaining`

- - ### Constructor Detail

    - #### MergedIterator

          public MergedIterator(Iterator<T>... iterators)

    - #### MergedIterator

          public MergedIterator(boolean removeDuplicates,
                                Iterator<T>... iterators)

  - ### Method Detail

    - #### hasNext

          public boolean hasNext()

      Specified by:
        `hasNext` in interface `Iterator<T extends Comparable<T>>`

    - #### next

          public T next()

      Specified by:
        `next` in interface `Iterator<T extends Comparable<T>>`

    - #### remove

          public void remove()

      Specified by:
        `remove` in interface `Iterator<T extends Comparable<T>>`

Copyright © 2000-2021 Apache Software Foundation. All Rights Reserved.