org.apache.lucene.search
Class Query

java.lang.Object
  extended by org.apache.lucene.search.Query
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable
Direct Known Subclasses:
BooleanQuery, FilteredQuery, MultiTermQuery, PhrasePrefixQuery, PhraseQuery, PrefixQuery, RangeQuery, SpanQuery, TermQuery

public abstract class Query
extends java.lang.Object
implements java.io.Serializable, java.lang.Cloneable

The abstract base class for queries.

Instantiable subclasses are:

A parser for queries is contained in:

See Also:
Serialized Form

Constructor Summary
Query()
           
 
Method Summary
 java.lang.Object clone()
          Returns a clone of this query.
 Query combine(Query[] queries)
          Expert: called when re-writing queries under MultiSearcher.
protected  Weight createWeight(Searcher searcher)
          Expert: Constructs an appropriate Weight implementation for this query.
 float getBoost()
          Gets the boost for this clause.
 Similarity getSimilarity(Searcher searcher)
          Expert: Returns the Similarity implementation to be used for this query.
static Query mergeBooleanQueries(Query[] queries)
          Expert: merges the clauses of a set of BooleanQuery's into a single BooleanQuery.
 Query rewrite(IndexReader reader)
          Expert: called to re-write queries into primitive queries.
 void setBoost(float b)
          Sets the boost for this query clause to b.
 java.lang.String toString()
          Prints a query to a string.
abstract  java.lang.String toString(java.lang.String field)
          Prints a query to a string, with field as the default field for terms.
 Weight weight(Searcher searcher)
          Expert: Constructs an initializes a Weight for a top-level query.
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

Query

public Query()
Method Detail

setBoost

public void setBoost(float b)
Sets the boost for this query clause to b. Documents matching this clause will (in addition to the normal weightings) have their score multiplied by b.


getBoost

public float getBoost()
Gets the boost for this clause. Documents matching this clause will (in addition to the normal weightings) have their score multiplied by b. The boost is 1.0 by default.


toString

public abstract java.lang.String toString(java.lang.String field)
Prints a query to a string, with field as the default field for terms.

The representation used is one that is readable by QueryParser (although, if the query was created by the parser, the printed representation may not be exactly what was parsed).


toString

public java.lang.String toString()
Prints a query to a string.

Overrides:
toString in class java.lang.Object

createWeight

protected Weight createWeight(Searcher searcher)
Expert: Constructs an appropriate Weight implementation for this query.

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


weight

public Weight weight(Searcher searcher)
              throws java.io.IOException
Expert: Constructs an initializes a Weight for a top-level query.

Throws:
java.io.IOException

rewrite

public Query rewrite(IndexReader reader)
              throws java.io.IOException
Expert: called to re-write queries into primitive queries.

Throws:
java.io.IOException

combine

public Query combine(Query[] queries)
Expert: called when re-writing queries under MultiSearcher.

Only implemented by derived queries, with no createWeight(Searcher) implementatation.


mergeBooleanQueries

public static Query mergeBooleanQueries(Query[] queries)
Expert: merges the clauses of a set of BooleanQuery's into a single BooleanQuery.

A utility for use by combine(Query[]) implementations.


getSimilarity

public Similarity getSimilarity(Searcher searcher)
Expert: Returns the Similarity implementation to be used for this query. Subclasses may override this method to specify their own Similarity implementation, perhaps one that delegates through that of the Searcher. By default the Searcher's Similarity implementation is returned.


clone

public java.lang.Object clone()
Returns a clone of this query.

Overrides:
clone in class java.lang.Object


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