org.apache.lucene.search.suggest.document

## Class ContextQuery

- java.lang.Object
- - org.apache.lucene.search.Query
  - - org.apache.lucene.search.suggest.document.CompletionQuery
    - - org.apache.lucene.search.suggest.document.ContextQuery

-     public class ContextQuery
      extends CompletionQuery

  A `CompletionQuery` that matches documents specified by a wrapped `CompletionQuery` supporting boosting and/or filtering by specified contexts.

  Use this query against `ContextSuggestField`

  Example of using a `CompletionQuery` with boosted contexts:

        CompletionQuery completionQuery = ...;
        ContextQuery query = new ContextQuery(completionQuery);
        query.addContext("context1", 2);
        query.addContext("context2", 1);

  NOTE:

  - This query can be constructed with `PrefixCompletionQuery`, `RegexCompletionQuery` or `FuzzyCompletionQuery` query.
  - To suggest across all contexts, use `addAllContexts()`. When no context is added, the default behaviour is to suggest across all contexts.
  - To apply the same boost to multiple contexts sharing the same prefix, Use `addContext(CharSequence, float, boolean)` with the common context prefix, boost and set `exact` to false.
  - Using this query against a `SuggestField` (not context enabled), would yield results ignoring any context filtering/boosting
  WARNING: This API is experimental and might change in incompatible ways in the next release.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `protected CompletionQuery` | `innerQuery` Inner completion query

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `ContextQuery(CompletionQuery query)` Constructs a context completion query that matches documents specified by `query`.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `addAllContexts()` Add all contexts with a boost of 1f
    `void` | `addContext(CharSequence context)` Adds an exact context with default boost of 1
    `void` | `addContext(CharSequence context, float boost)` Adds an exact context with boost
    `void` | `addContext(CharSequence context, float boost, boolean exact)` Adds a context with boost, set `exact` to false if the context is a prefix of any indexed contexts
    `Weight` | `createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost)`
    `boolean` | `equals(Object o)`
    `int` | `hashCode()`
    `String` | `toString(String field)`
    `void` | `visit(QueryVisitor visitor)`

    - ### Methods inherited from class org.apache.lucene.search.suggest.document.CompletionQuery

      `getField, getFilter, getTerm, rewrite`

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

      `classHash, sameClassAs, toString`

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

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

- - ### Field Detail

    - #### innerQuery

          protected CompletionQuery innerQuery

      Inner completion query

  - ### Constructor Detail

    - #### ContextQuery

          public ContextQuery(CompletionQuery query)

      Constructs a context completion query that matches documents specified by `query`.

      Use `addContext(CharSequence, float, boolean)` to add context(s) with boost

  - ### Method Detail

    - #### addContext

          public void addContext(CharSequence context)

      Adds an exact context with default boost of 1

    - #### addContext

          public void addContext(CharSequence context,
                                 float boost)

      Adds an exact context with boost

    - #### addContext

          public void addContext(CharSequence context,
                                 float boost,
                                 boolean exact)

      Adds a context with boost, set `exact` to false if the context is a prefix of any indexed contexts

    - #### addAllContexts

          public void addAllContexts()

      Add all contexts with a boost of 1f

    - #### toString

          public String toString(String field)

      Overrides:
        `toString` in class `CompletionQuery`

    - #### createWeight

          public Weight createWeight(IndexSearcher searcher,
                                     ScoreMode scoreMode,
                                     float boost)
                              throws IOException

      Overrides:
        `createWeight` in class `Query`
      Throws:
        `IOException`

    - #### equals

          public boolean equals(Object o)

      Specified by:
        `equals` in class `Query`

    - #### hashCode

          public int hashCode()

      Specified by:
        `hashCode` in class `Query`

    - #### visit

          public void visit(QueryVisitor visitor)

      Overrides:
        `visit` in class `Query`

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