Overview | Package | Class | Use | Tree | Deprecated | Help
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

## org.apache.lucene.search
Class ScoringRewrite<Q extends Query>

    java.lang.Object
      org.apache.lucene.search.MultiTermQuery.RewriteMethod
          org.apache.lucene.search.ScoringRewrite<Q>

    public abstract class ScoringRewrite<Q extends Query>

extends MultiTermQuery.RewriteMethod

Base rewrite method that translates each term into a query, and keeps the scores as computed by the query.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.
  Only public to be accessible by spans package.

Field Summary
`static MultiTermQuery.RewriteMethod` | `CONSTANT_SCORE_BOOLEAN_QUERY_REWRITE` Like `SCORING_BOOLEAN_QUERY_REWRITE` except scores are not computed.
`static ScoringRewrite<BooleanQuery>` | `SCORING_BOOLEAN_QUERY_REWRITE` A rewrite method that first translates each term into `BooleanClause.Occur.SHOULD` clause in a BooleanQuery, and keeps the scores as computed by the query.

Constructor Summary
`ScoringRewrite()`

Method Summary
`protected void` | `addClause(Q topLevel, Term term, int docCount, float boost)` Add a MultiTermQuery term to the top-level query
`protected abstract void` | `addClause(Q topLevel, Term term, int docCount, float boost, TermContext states)`
`protected abstract void` | `checkMaxClauseCount(int count)` This method is called after every new term to check if the number of max clauses (e.g.
`protected abstract Q` | `getTopLevelQuery()` Return a suitable top-level Query for holding all expanded terms.
`Q` | `rewrite(IndexReader reader, MultiTermQuery query)`

Methods inherited from class org.apache.lucene.search.MultiTermQuery.RewriteMethod
`getTermsEnum`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### SCORING_BOOLEAN_QUERY_REWRITE

    public static final ScoringRewrite<BooleanQuery> SCORING_BOOLEAN_QUERY_REWRITE

  A rewrite method that first translates each term into `BooleanClause.Occur.SHOULD` clause in a BooleanQuery, and keeps the scores as computed by the query. Note that typically such scores are meaningless to the user, and require non-trivial CPU to compute, so it's almost always better to use `MultiTermQuery.CONSTANT_SCORE_AUTO_REWRITE_DEFAULT` instead.

  NOTE: This rewrite method will hit `BooleanQuery.TooManyClauses` if the number of terms exceeds `BooleanQuery.getMaxClauseCount()`.

  See Also:
    `MultiTermQuery.setRewriteMethod(org.apache.lucene.search.MultiTermQuery.RewriteMethod)`

### CONSTANT_SCORE_BOOLEAN_QUERY_REWRITE

    public static final MultiTermQuery.RewriteMethod CONSTANT_SCORE_BOOLEAN_QUERY_REWRITE

  Like `SCORING_BOOLEAN_QUERY_REWRITE` except scores are not computed. Instead, each matching document receives a constant score equal to the query's boost.

  NOTE: This rewrite method will hit `BooleanQuery.TooManyClauses` if the number of terms exceeds `BooleanQuery.getMaxClauseCount()`.

  See Also:
    `MultiTermQuery.setRewriteMethod(org.apache.lucene.search.MultiTermQuery.RewriteMethod)`

Constructor Detail

### ScoringRewrite

    public ScoringRewrite()

Method Detail

### checkMaxClauseCount

    protected abstract void checkMaxClauseCount(int count)
                                         throws IOException

  This method is called after every new term to check if the number of max clauses (e.g. in BooleanQuery) is not exceeded. Throws the corresponding `RuntimeException`.

  Throws:
    `IOException`

### rewrite

    public final Q rewrite(IndexReader reader,
                           MultiTermQuery query)
                                  throws IOException

  Specified by:
    `rewrite` in class `MultiTermQuery.RewriteMethod`
  Throws:
    `IOException`

### getTopLevelQuery

    protected abstract Q getTopLevelQuery()
                                                 throws IOException

  Return a suitable top-level Query for holding all expanded terms.

  Throws:
    `IOException`

### addClause

    protected final void addClause(Q topLevel,
                                   Term term,
                                   int docCount,
                                   float boost)
                            throws IOException

  Add a MultiTermQuery term to the top-level query

  Throws:
    `IOException`

### addClause

    protected abstract void addClause(Q topLevel,
                                      Term term,
                                      int docCount,
                                      float boost,
                                      TermContext states)
                               throws IOException

  Throws:
    `IOException`

Overview | Package | Class | Use | Tree | Deprecated | Help
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

Copyright © 2000-2013 Apache Software Foundation. All Rights Reserved.