Package org.eclipse.rdf4j.common.iteration

## Class ConvertingIteration<S,​T,​X extends Exception>

- java.lang.Object
- - org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<T,​X>
  - - org.eclipse.rdf4j.common.iteration.ConvertingIteration<S,​T,​X>

- All Implemented Interfaces:
    `AutoCloseable`, `CloseableIteration<T,​X>`, `Iteration<T,​X>`
  Direct Known Subclasses:
    `BoundJoinConversionIteration`, `BoundJoinVALUESConversionIteration`, `ExtensionIterator`, `GroupedCheckConversionIteration`, `InsertBindingsIteration`, `ProjectionIterator`, `ServiceJoinConversionIteration`

      public abstract class ConvertingIteration<S,​T,​X extends Exception>
      extends AbstractCloseableIteration<T,​X>

  A CloseableIteration that converts an iteration over objects of type S (the source type) to an iteration over objects of type T (the target type).

- - ### Constructor Summary

    Constructors
    Modifier | Constructor | Description
    --- | --- | ---
    `protected` | `ConvertingIteration​(Iteration<? extends S,​? extends X> iter)` | Creates a new ConvertingIteration that operates on the supplied source type iteration.

  - ### Method Summary

    All Methods Instance Methods Abstract Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `protected abstract T` | `convert​(S sourceObject)` | Converts a source type object to a target type object.
    `protected void` | `handleClose()` | Closes this iteration as well as the wrapped iteration if it is a `CloseableIteration`.
    `boolean` | `hasNext()` | Checks whether the source type iteration contains more elements.
    `T` | `next()` | Returns the next element from the source type iteration.
    `void` | `remove()` | Calls remove() on the underlying Iteration.

    - ### 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

    - #### ConvertingIteration

          protected ConvertingIteration​(Iteration<? extends S,​? extends X> iter)

      Creates a new ConvertingIteration that operates on the supplied source type iteration.
      Parameters:
        `iter` - The source type iteration for this ConvertingIteration, must not be null.

  - ### Method Detail

    - #### convert

          protected abstract T convert​(S sourceObject)
                                throws X extends Exception

      Converts a source type object to a target type object.
      Throws:
        `X extends Exception`

    - #### hasNext

          public boolean hasNext()
                          throws X extends Exception

      Checks whether the source type iteration contains more elements.
      Returns:
        true if the source type iteration contains more elements, false otherwise.
      Throws:
        `X`
        `X`
        `X extends Exception`

    - #### next

          public T next()
                 throws X extends Exception

      Returns the next element from the source type iteration.
      Returns:
        the next element in the iteration.
      Throws:
        `X`
        `NoSuchElementException` - If all elements have been returned.
        `IllegalStateException` - If the iteration has been closed.
        `X extends Exception`

    - #### remove

          public void remove()
                      throws X extends Exception

      Calls remove() on the underlying Iteration.
      Throws:
        `UnsupportedOperationException` - If the wrapped Iteration does not support the remove operation.
        `IllegalStateException` - If the Iteration has been closed, or if `next()` has not yet been called, or `remove()` has already been called after the last call to `next()`.
        `X extends Exception`

    - #### handleClose

          protected void handleClose()
                              throws X extends Exception

      Closes this iteration as well as the wrapped iteration if it is a `CloseableIteration`.
      Overrides:
        `handleClose` in class `AbstractCloseableIteration<T,​X extends Exception>`
      Throws:
        `X`
        `X extends Exception`