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

All Implemented Interfaces:

Serializable, Cloneable
```
public class ConstantScoreQuery
extends Query
```
A query that wraps another query or a filter and simply returns a constant score equal to the query boost for every document that matches the filter or query. For queries it therefore simply strips of all scores and returns a constant one.
NOTE: if the wrapped filter is an instance of CachingWrapperFilter, you'll likely want to enforce deletions in the filter (using either CachingWrapperFilter.DeletesMode.RECACHE or CachingWrapperFilter.DeletesMode.DYNAMIC).

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type Class Description

protected class ConstantScoreQuery.ConstantScorer

protected class ConstantScoreQuery.ConstantWeight

Field Summary

Fields
Modifier and Type Field Description

protected Filter filter

protected Query query

Constructor Summary

Constructors
Constructor Description

ConstantScoreQuery(Filter filter)
Wraps a Filter as a Query.

ConstantScoreQuery(Query query)
Strips off scores from the passed in Query.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Weight`	`createWeight(Searcher searcher)`	Expert: Constructs an appropriate Weight implementation for this query.
`boolean`	`equals(Object o)`
`void`	`extractTerms(Set<Term> terms)`	Expert: adds all terms occurring in this query to the terms set.
`Filter`	`getFilter()`	Returns the encapsulated filter, returns `null` if a query is wrapped.
`Query`	`getQuery()`	Returns the encapsulated query, returns `null` if a filter is wrapped.
`int`	`hashCode()`
`Query`	`rewrite(IndexReader reader)`	Expert: called to re-write queries into primitive queries.
`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
clone, combine, getBoost, getSimilarity, mergeBooleanQueries, setBoost, toString, weight

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - filter
```
protected final Filter filter
```
  - query
```
protected final Query query
```
- Constructor Detail
  - ConstantScoreQuery
```
public ConstantScoreQuery(Query query)
```
    Strips off scores from the passed in Query. The hits will get a constant score dependent on the boost factor of this query.
  - ConstantScoreQuery
```
public ConstantScoreQuery(Filter filter)
```
    Wraps a Filter as a Query. The hits will get a constant score dependent on the boost factor of this query. If you simply want to strip off scores from a Query, no longer use new ConstantScoreQuery(new QueryWrapperFilter(query)), instead use ConstantScoreQuery(Query)!
- Method Detail
  - getFilter
```
public Filter getFilter()
```
    Returns the encapsulated filter, returns null if a query is wrapped.
  - getQuery
```
public Query getQuery()
```
    Returns the encapsulated query, returns null if a filter is wrapped.
  - rewrite
```
public Query rewrite(IndexReader reader)
              throws IOException
```
    Description copied from class: Query
    
    Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.
    
    Overrides:
    
    rewrite in class Query
    
    Throws:
    
    IOException
  - extractTerms
```
public void extractTerms(Set<Term> terms)
```
    Description copied from class: Query
    
    Expert: adds all terms occurring in this query to the terms set. Only works if this query is in its rewritten form.
    
    Overrides:
    
    extractTerms in class Query
  - createWeight
```
public Weight createWeight(Searcher searcher)
                    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
    
    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.
    The representation used is one that is supposed to be readable by QueryParser. However, there are the following limitations:
    
    If the query was created by the parser, the printed representation may not be exactly what was parsed. For example, characters that need to be escaped will be represented without the required backslash.
    
    Some of the more complicated queries (e.g. span queries) don't have a representation that can be parsed by QueryParser.
    Specified by:
    
    toString in class Query
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Query
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Query

Modifier and Type	Class	Description
`protected class`	`ConstantScoreQuery.ConstantScorer`
`protected class`	`ConstantScoreQuery.ConstantWeight`

Constructor	Description
`ConstantScoreQuery(Filter filter)`	Wraps a Filter as a Query.
`ConstantScoreQuery(Query query)`	Strips off scores from the passed in Query.

Class ConstantScoreQuery

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Field Detail

filter

query

Constructor Detail

ConstantScoreQuery

ConstantScoreQuery

Method Detail

getFilter

getQuery

rewrite

extractTerms

createWeight

toString

equals

hashCode