org.apache.lucene.search

## Class SortedNumericSortField

- java.lang.Object
- - org.apache.lucene.search.SortField
  - - org.apache.lucene.search.SortedNumericSortField

-     public class SortedNumericSortField
      extends SortField

  SortField for `SortedNumericDocValues`.

  A SortedNumericDocValues contains multiple values for a field, so sorting with this technique "selects" a value as the representative sort value for the document.

  By default, the minimum value in the list is selected as the sort value, but this can be customized.

  Like sorting by string, this also supports sorting missing values as first or last, via `setMissingValue(Object)`.

  See Also:
    `SortedNumericSelector`

- - ### Nested Class Summary

    - ### Nested classes/interfaces inherited from class org.apache.lucene.search.SortField

      `SortField.Type`

  - ### Field Summary

    - ### Fields inherited from class org.apache.lucene.search.SortField

      `FIELD_DOC, FIELD_SCORE, missingValue, STRING_FIRST, STRING_LAST`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `SortedNumericSortField(String field, SortField.Type type)` Creates a sort, by the minimum value in the set for the document.
    `SortedNumericSortField(String field, SortField.Type type, boolean reverse)` Creates a sort, possibly in reverse, by the minimum value in the set for the document.
    `SortedNumericSortField(String field, SortField.Type type, boolean reverse, SortedNumericSelector.Type selector)` Creates a sort, possibly in reverse, specifying how the sort value from the document's set is selected.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `equals(Object obj)` Returns true if `o` is equal to this.
    `FieldComparator<?>` | `getComparator(int numHits, int sortPos)` Returns the `FieldComparator` to use for sorting.
    `SortedNumericSelector.Type` | `getSelector()` Returns the selector in use for this sort
    `int` | `hashCode()` Returns a hash code for this `SortField` instance.
    `void` | `setMissingValue(Object missingValue)`
    `String` | `toString()`

    - ### Methods inherited from class org.apache.lucene.search.SortField

      `getBytesComparator, getComparatorSource, getField, getReverse, getType, needsScores, rewrite, setBytesComparator`

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

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### SortedNumericSortField

          public SortedNumericSortField(String field,
                                SortField.Type type)

      Creates a sort, by the minimum value in the set for the document.
      Parameters:
        `field` - Name of field to sort by. Must not be null.
        `type` - Type of values

    - #### SortedNumericSortField

          public SortedNumericSortField(String field,
                                SortField.Type type,
                                boolean reverse)

      Creates a sort, possibly in reverse, by the minimum value in the set for the document.
      Parameters:
        `field` - Name of field to sort by. Must not be null.
        `type` - Type of values
        `reverse` - True if natural order should be reversed.

    - #### SortedNumericSortField

          public SortedNumericSortField(String field,
                                SortField.Type type,
                                boolean reverse,
                                SortedNumericSelector.Type selector)

      Creates a sort, possibly in reverse, specifying how the sort value from the document's set is selected.
      Parameters:
        `field` - Name of field to sort by. Must not be null.
        `type` - Type of values
        `reverse` - True if natural order should be reversed.
        `selector` - custom selector type for choosing the sort value from the set.

  - ### Method Detail

    - #### getSelector

          public SortedNumericSelector.Type getSelector()

      Returns the selector in use for this sort

    - #### hashCode

          public int hashCode()

      Description copied from class: `SortField`
      Returns a hash code for this `SortField` instance. If a `FieldComparatorSource` was provided, it must properly implement hashCode (unless a singleton is always used).
      Overrides:
        `hashCode` in class `SortField`

    - #### equals

          public boolean equals(Object obj)

      Description copied from class: `SortField`
      Returns true if `o` is equal to this. If a `FieldComparatorSource` was provided, it must properly implement equals (unless a singleton is always used).
      Overrides:
        `equals` in class `SortField`

    - #### toString

          public String toString()

      Overrides:
        `toString` in class `SortField`

    - #### setMissingValue

          public void setMissingValue(Object missingValue)

      Overrides:
        `setMissingValue` in class `SortField`

    - #### getComparator

          public FieldComparator<?> getComparator(int numHits,
                                         int sortPos)
                                           throws IOException

      Description copied from class: `SortField`
      Returns the `FieldComparator` to use for sorting.
      Overrides:
        `getComparator` in class `SortField`
      Parameters:
        `numHits` - number of top hits the queue will store
        `sortPos` - position of this SortField within `Sort`. The comparator is primary if sortPos==0, secondary if sortPos==1, etc. Some comparators can optimize themselves when they are the primary sort.
      Returns:
        `FieldComparator` to use when sorting
      Throws:
        `IOException`

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