org.apache.lucene.search

## Class MatchNoDocsQuery

- java.lang.Object
- - org.apache.lucene.search.Query
  - - org.apache.lucene.search.MatchNoDocsQuery

-     public class MatchNoDocsQuery
      extends Query

  A query that matches no documents.

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `MatchNoDocsQuery()` Default constructor
    `MatchNoDocsQuery(String reason)` Provides a reason explaining why this query was used

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `Weight` | `createWeight(IndexSearcher searcher, boolean needsScores, float boost)` Expert: Constructs an appropriate Weight implementation for this query.
    `boolean` | `equals(Object o)` Override and implement query instance equivalence properly in a subclass.
    `int` | `hashCode()` Override and implement query hash code properly in a subclass.
    `String` | `toString(String field)` Prints a query to a string, with `field` assumed to be the default field and omitted.

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

      `classHash, rewrite, sameClassAs, toString`

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

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

- - ### Constructor Detail

    - #### MatchNoDocsQuery

          public MatchNoDocsQuery()

      Default constructor

    - #### MatchNoDocsQuery

          public MatchNoDocsQuery(String reason)

      Provides a reason explaining why this query was used

  - ### Method Detail

    - #### createWeight

          public Weight createWeight(IndexSearcher searcher,
                                     boolean needsScores,
                                     float boost)
                              throws IOException

      Description copied from class: `Query`
      Expert: Constructs an appropriate Weight implementation for this query.

      Only implemented by primitive queries, which re-write to themselves.

      Overrides:
        `createWeight` in class `Query`
        `needsScores` - True if document scores (`Scorer.score()`) are needed.
        `boost` - The boost that is propagated by the parent queries.
      Throws:
        `IOException`

    - #### toString

          public String toString(String field)

      Description copied from class: `Query`
      Prints a query to a string, with `field` assumed to be the default field and omitted.
      Specified by:
        `toString` in class `Query`

    - #### equals

          public boolean equals(Object o)

      Description copied from class: `Query`
      Override and implement query instance equivalence properly in a subclass. This is required so that `QueryCache` works properly. Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical that other instance. Utility methods are provided for certain repetitive code.
      Specified by:
        `equals` in class `Query`
      See Also:
        `Query.sameClassAs(Object)`, `Query.classHash()`

    - #### hashCode

          public int hashCode()

      Description copied from class: `Query`
      Override and implement query hash code properly in a subclass. This is required so that `QueryCache` works properly.
      Specified by:
        `hashCode` in class `Query`
      See Also:
        `Query.equals(Object)`

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