org.eclipse.rdf4j.common.iteration

## Class UnionIteration<E,X extends Exception>

- java.lang.Object
- - org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E,X>
  - - org.eclipse.rdf4j.common.iteration.LookAheadIteration<E,X>
    - - org.eclipse.rdf4j.common.iteration.UnionIteration<E,X>

- All Implemented Interfaces:
    AutoCloseable, CloseableIteration<E,X>, Iteration<E,X>

      public class UnionIteration<E,X extends Exception>
      extends LookAheadIteration<E,X>

  An Iteration that returns the bag union of the results of a number of Iterations. 'Bag union' means that the UnionIteration does not filter duplicate objects.

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `UnionIteration(Iterable<? extends Iteration<? extends E,X>> args)` Creates a new UnionIteration that returns the bag union of the results of a number of Iterations.
    `UnionIteration(Iteration<? extends E,X>... args)` Creates a new UnionIteration that returns the bag union of the results of a number of Iterations.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `protected E` | `getNextElement()` Gets the next element.
    `protected void` | `handleClose()` Called by `AbstractCloseableIteration.close()` when it is called for the first time.

    - ### Methods inherited from class org.eclipse.rdf4j.common.iteration.LookAheadIteration

      `hasNext, next, remove`

    - ### Methods inherited from class org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration

      `close, isClosed`

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

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

    - ### Methods inherited from interface org.eclipse.rdf4j.common.iteration.Iteration

      `stream`

- - ### Constructor Detail

    - #### UnionIteration

          public UnionIteration(Iteration<? extends E,X>... args)

      Creates a new UnionIteration that returns the bag union of the results of a number of Iterations.
      Parameters:
        `args` - The Iterations containing the elements to iterate over.

    - #### UnionIteration

          public UnionIteration(Iterable<? extends Iteration<? extends E,X>> args)

      Creates a new UnionIteration that returns the bag union of the results of a number of Iterations.
      Parameters:
        `args` - The Iterations containing the elements to iterate over.

  - ### Method Detail

    - #### getNextElement

          protected E getNextElement()
                              throws X extends Exception

      Description copied from class: `LookAheadIteration`
      Gets the next element. Subclasses should implement this method so that it returns the next element.
      Specified by:
        `getNextElement` in class `LookAheadIteration<E,X extends Exception>`
      Returns:
        The next element, or `null` if no more elements are available.
      Throws:
        `X extends Exception`

    - #### handleClose

          protected void handleClose()
                              throws X extends Exception

      Description copied from class: `AbstractCloseableIteration`
      Called by `AbstractCloseableIteration.close()` when it is called for the first time. This method is only called once on each iteration. By default, this method does nothing.
      Overrides:
        `handleClose` in class `LookAheadIteration<E,X extends Exception>`
      Throws:
        `X`
        `X extends Exception`

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