DocValues (Lucene 6.0.1 API)

java.lang.Object
- org.apache.lucene.index.DocValues

```
public final class DocValues
extends Object
```
This class contains utility methods and constants for DocValues

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static Bits`	`docsWithValue(SortedDocValues dv, int maxDoc)` Returns a Bits representing all documents from `dv` that have a value.
`static Bits`	`docsWithValue(SortedNumericDocValues dv, int maxDoc)` Returns a Bits representing all documents from `dv` that have a value.
`static Bits`	`docsWithValue(SortedSetDocValues dv, int maxDoc)` Returns a Bits representing all documents from `dv` that have a value.
`static BinaryDocValues`	`emptyBinary()` An empty BinaryDocValues which returns `BytesRef.EMPTY_BYTES` for every document
`static NumericDocValues`	`emptyNumeric()` An empty NumericDocValues which returns zero for every document
`static SortedDocValues`	`emptySorted()` An empty SortedDocValues which returns `BytesRef.EMPTY_BYTES` for every document
`static SortedNumericDocValues`	`emptySortedNumeric(int maxDoc)` An empty SortedNumericDocValues which returns zero values for every document
`static RandomAccessOrds`	`emptySortedSet()` An empty SortedDocValues which returns `SortedSetDocValues.NO_MORE_ORDS` for every document
`static BinaryDocValues`	`getBinary(LeafReader reader, String field)` Returns BinaryDocValues for the field, or `emptyBinary()` if it has none.
`static Bits`	`getDocsWithField(LeafReader reader, String field)` Returns Bits for the field, or `Bits` matching nothing if it has none.
`static NumericDocValues`	`getNumeric(LeafReader reader, String field)` Returns NumericDocValues for the field, or `emptyNumeric()` if it has none.
`static SortedDocValues`	`getSorted(LeafReader reader, String field)` Returns SortedDocValues for the field, or `emptySorted()` if it has none.
`static SortedNumericDocValues`	`getSortedNumeric(LeafReader reader, String field)` Returns SortedNumericDocValues for the field, or `emptySortedNumeric(int)` if it has none.
`static SortedSetDocValues`	`getSortedSet(LeafReader reader, String field)` Returns SortedSetDocValues for the field, or `emptySortedSet()` if it has none.
`static SortedNumericDocValues`	`singleton(NumericDocValues dv, Bits docsWithField)` Returns a multi-valued view over the provided NumericDocValues
`static RandomAccessOrds`	`singleton(SortedDocValues dv)` Returns a multi-valued view over the provided SortedDocValues
`static NumericDocValues`	`unwrapSingleton(SortedNumericDocValues dv)` Returns a single-valued view of the SortedNumericDocValues, if it was previously wrapped with `singleton(NumericDocValues, Bits)`, or null.
`static SortedDocValues`	`unwrapSingleton(SortedSetDocValues dv)` Returns a single-valued view of the SortedSetDocValues, if it was previously wrapped with `singleton(SortedDocValues)`, or null.
`static Bits`	`unwrapSingletonBits(SortedNumericDocValues dv)` Returns the documents with a value for the SortedNumericDocValues, if it was previously wrapped with `singleton(NumericDocValues, Bits)`, or null.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - emptyBinary
```
public static final BinaryDocValues emptyBinary()
```
    An empty BinaryDocValues which returns BytesRef.EMPTY_BYTES for every document
  - emptyNumeric
```
public static final NumericDocValues emptyNumeric()
```
    An empty NumericDocValues which returns zero for every document
  - emptySorted
```
public static final SortedDocValues emptySorted()
```
    An empty SortedDocValues which returns BytesRef.EMPTY_BYTES for every document
  - emptySortedNumeric
```
public static final SortedNumericDocValues emptySortedNumeric(int maxDoc)
```
    An empty SortedNumericDocValues which returns zero values for every document
  - emptySortedSet
```
public static final RandomAccessOrds emptySortedSet()
```
    An empty SortedDocValues which returns SortedSetDocValues.NO_MORE_ORDS for every document
  - singleton
```
public static RandomAccessOrds singleton(SortedDocValues dv)
```
    Returns a multi-valued view over the provided SortedDocValues
  - unwrapSingleton
```
public static SortedDocValues unwrapSingleton(SortedSetDocValues dv)
```
    Returns a single-valued view of the SortedSetDocValues, if it was previously wrapped with singleton(SortedDocValues), or null.
  - unwrapSingleton
```
public static NumericDocValues unwrapSingleton(SortedNumericDocValues dv)
```
    Returns a single-valued view of the SortedNumericDocValues, if it was previously wrapped with singleton(NumericDocValues, Bits), or null.
    
    See Also:
    
    unwrapSingletonBits(SortedNumericDocValues)
  - unwrapSingletonBits
```
public static Bits unwrapSingletonBits(SortedNumericDocValues dv)
```
    Returns the documents with a value for the SortedNumericDocValues, if it was previously wrapped with singleton(NumericDocValues, Bits), or null.
  - singleton
```
public static SortedNumericDocValues singleton(NumericDocValues dv,
                                               Bits docsWithField)
```
    Returns a multi-valued view over the provided NumericDocValues
  - docsWithValue
```
public static Bits docsWithValue(SortedDocValues dv,
                                 int maxDoc)
```
    Returns a Bits representing all documents from dv that have a value.
  - docsWithValue
```
public static Bits docsWithValue(SortedSetDocValues dv,
                                 int maxDoc)
```
    Returns a Bits representing all documents from dv that have a value.
  - docsWithValue
```
public static Bits docsWithValue(SortedNumericDocValues dv,
                                 int maxDoc)
```
    Returns a Bits representing all documents from dv that have a value.
  - getNumeric
```
public static NumericDocValues getNumeric(LeafReader reader,
                                          String field)
                                   throws IOException
```
    Returns NumericDocValues for the field, or emptyNumeric() if it has none.
    
    Returns:
    
    docvalues instance, or an empty instance if field does not exist in this reader.
    
    Throws:
    
    IllegalStateException - if field exists, but was not indexed with docvalues.
    
    IllegalStateException - if field has docvalues, but the type is not DocValuesType.NUMERIC.
    
    IOException - if an I/O error occurs.
  - getBinary
```
public static BinaryDocValues getBinary(LeafReader reader,
                                        String field)
                                 throws IOException
```
    Returns BinaryDocValues for the field, or emptyBinary() if it has none.
    
    Returns:
    
    docvalues instance, or an empty instance if field does not exist in this reader.
    
    Throws:
    
    IllegalStateException - if field exists, but was not indexed with docvalues.
    
    IllegalStateException - if field has docvalues, but the type is not DocValuesType.BINARY or DocValuesType.SORTED.
    
    IOException - if an I/O error occurs.
  - getSorted
```
public static SortedDocValues getSorted(LeafReader reader,
                                        String field)
                                 throws IOException
```
    Returns SortedDocValues for the field, or emptySorted() if it has none.
    
    Returns:
    
    docvalues instance, or an empty instance if field does not exist in this reader.
    
    Throws:
    
    IllegalStateException - if field exists, but was not indexed with docvalues.
    
    IllegalStateException - if field has docvalues, but the type is not DocValuesType.SORTED.
    
    IOException - if an I/O error occurs.
  - getSortedNumeric
```
public static SortedNumericDocValues getSortedNumeric(LeafReader reader,
                                                      String field)
                                               throws IOException
```
    Returns SortedNumericDocValues for the field, or emptySortedNumeric(int) if it has none.
    
    Returns:
    
    docvalues instance, or an empty instance if field does not exist in this reader.
    
    Throws:
    
    IllegalStateException - if field exists, but was not indexed with docvalues.
    
    IllegalStateException - if field has docvalues, but the type is not DocValuesType.SORTED_NUMERIC or DocValuesType.NUMERIC.
    
    IOException - if an I/O error occurs.
  - getSortedSet
```
public static SortedSetDocValues getSortedSet(LeafReader reader,
                                              String field)
                                       throws IOException
```
    Returns SortedSetDocValues for the field, or emptySortedSet() if it has none.
    
    Returns:
    
    docvalues instance, or an empty instance if field does not exist in this reader.
    
    Throws:
    
    IllegalStateException - if field exists, but was not indexed with docvalues.
    
    IllegalStateException - if field has docvalues, but the type is not DocValuesType.SORTED_SET or DocValuesType.SORTED.
    
    IOException - if an I/O error occurs.
  - getDocsWithField
```
public static Bits getDocsWithField(LeafReader reader,
                                    String field)
                             throws IOException
```
    Returns Bits for the field, or Bits matching nothing if it has none.
    
    Returns:
    
    bits instance, or an empty instance if field does not exist in this reader.
    
    Throws:
    
    IllegalStateException - if field exists, but was not indexed with docvalues.
    
    IOException - if an I/O error occurs.

Class DocValues

Method Summary

Methods inherited from class java.lang.Object

Method Detail

emptyBinary

emptyNumeric

emptySorted

emptySortedNumeric

emptySortedSet

singleton

unwrapSingleton

unwrapSingleton

unwrapSingletonBits

singleton

docsWithValue

docsWithValue

docsWithValue

getNumeric

getBinary

getSorted

getSortedNumeric

getSortedSet

getDocsWithField