Package org.apache.lucene.queries.function.valuesource

## Class JoinDocFreqValueSource

- java.lang.Object
- - org.apache.lucene.queries.function.ValueSource
  - - org.apache.lucene.queries.function.valuesource.FieldCacheSource
    - - org.apache.lucene.queries.function.valuesource.JoinDocFreqValueSource

-     public class JoinDocFreqValueSource
      extends FieldCacheSource

  Use a field value and find the Document Frequency within another field.
  Since:
    solr 4.0

- - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `static String` | `NAME` |
    `protected String` | `qfield` |

    - ### Fields inherited from class org.apache.lucene.queries.function.valuesource.FieldCacheSource

      `field`

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `JoinDocFreqValueSource​(String field, String qfield)` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `String` | `description()` | description of field, used in explain()
    `boolean` | `equals​(Object o)` |
    `FunctionValues` | `getValues​(Map<Object,​Object> context, LeafReaderContext readerContext)` | Gets the values for this reader and the context that was previously passed to createWeight().
    `int` | `hashCode()` |

    - ### Methods inherited from class org.apache.lucene.queries.function.valuesource.FieldCacheSource

      `getField`

    - ### Methods inherited from class org.apache.lucene.queries.function.ValueSource

      `asDoubleValuesSource, asLongValuesSource, createWeight, fromDoubleValuesSource, getSortField, newContext, toString`

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

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

- - ### Field Detail

    - #### NAME

          public static final String NAME

      See Also:
        Constant Field Values

    - #### qfield

          protected final String qfield

  - ### Constructor Detail

    - #### JoinDocFreqValueSource

          public JoinDocFreqValueSource​(String field,
                                        String qfield)

  - ### Method Detail

    - #### description

          public String description()

      Description copied from class: `ValueSource`
      description of field, used in explain()
      Overrides:
        `description` in class `FieldCacheSource`

    - #### getValues

          public FunctionValues getValues​(Map<Object,​Object> context,
                                          LeafReaderContext readerContext)
                                   throws IOException

      Description copied from class: `ValueSource`
      Gets the values for this reader and the context that was previously passed to createWeight(). The values must be consumed in a forward docID manner, and you must call this method again to iterate through the values again.
      Specified by:
        `getValues` in class `ValueSource`
      Throws:
        `IOException`

    - #### equals

          public boolean equals​(Object o)

      Overrides:
        `equals` in class `FieldCacheSource`

    - #### hashCode

          public int hashCode()

      Overrides:
        `hashCode` in class `FieldCacheSource`