Package org.apache.lucene.search.highlight

Class QueryScorer

  • All Implemented Interfaces:
    Scorer
    public class QueryScorer
extends java.lang.Object
implements Scorer
    Scorer implementation which scores text fragments by the number of unique query terms found. This class converts appropriate Querys to SpanQuerys and attempts to score only those terms that participated in generating the 'hit' on the document.

    • Field Detail

      • totalScore

        private float totalScore

      • foundTerms

        private java.util.Set<java.lang.String> foundTerms

      • fieldWeightedSpanTerms

        private java.util.Map<java.lang.String,​WeightedSpanTerm> fieldWeightedSpanTerms

      • maxTermWeight

        private float maxTermWeight

      • position

        private int position

      • defaultField

        private java.lang.String defaultField

      • expandMultiTermQuery

        private boolean expandMultiTermQuery

      • query

        private Query query

      • field

        private java.lang.String field

      • skipInitExtractor

        private boolean skipInitExtractor

      • wrapToCaching

        private boolean wrapToCaching

      • maxCharsToAnalyze

        private int maxCharsToAnalyze

      • usePayloads

        private boolean usePayloads

    • Constructor Detail

      • QueryScorer

        public QueryScorer​(Query query)
        Parameters:
        query - Query to use for highlighting

      • QueryScorer

        public QueryScorer​(Query query,
                   java.lang.String field)
        Parameters:
        query - Query to use for highlighting
        field - Field to highlight - pass null to ignore fields

      • QueryScorer

        public QueryScorer​(Query query,
                   IndexReader reader,
                   java.lang.String field)
        Parameters:
        query - Query to use for highlighting
        field - Field to highlight - pass null to ignore fields
        reader - IndexReader to use for quasi tf/idf scoring

      • QueryScorer

        public QueryScorer​(Query query,
                   IndexReader reader,
                   java.lang.String field,
                   java.lang.String defaultField)
        Parameters:
        query - to use for highlighting
        reader - IndexReader to use for quasi tf/idf scoring
        field - to highlight - pass null to ignore fields

      • QueryScorer

        public QueryScorer​(Query query,
                   java.lang.String field,
                   java.lang.String defaultField)
        Parameters:
        defaultField - - The default field for queries with the field name unspecified

    • Method Detail

      • getFragmentScore

        public float getFragmentScore()
        Description copied from interface: Scorer
        Called when the Highlighter has no more tokens for the current fragment - the Scorer returns the weighting it has derived for the most recent fragment, typically based on the results of Scorer.getTokenScore().
        Specified by:
        getFragmentScore in interface Scorer

      • getMaxTermWeight

        public float getMaxTermWeight()
        Returns:
        The highest weighted term (useful for passing to GradientFormatter to set top end of coloring scale).

      • getTokenScore

        public float getTokenScore()
        Description copied from interface: Scorer
        Called for each token in the current fragment. The Highlighter will increment the TokenStream passed to init on every call.
        Specified by:
        getTokenScore in interface Scorer
        Returns:
        a score which is passed to the Highlighter class to influence the mark-up of the text (this return value is NOT used to score the fragment)

      • init

        public TokenStream init​(TokenStream tokenStream)
                 throws java.io.IOException
        Description copied from interface: Scorer
        Called to init the Scorer with a TokenStream. You can grab references to the attributes you are interested in here and access them from Scorer.getTokenScore().
        Specified by:
        init in interface Scorer
        Parameters:
        tokenStream - the TokenStream that will be scored.
        Returns:
        either a TokenStream that the Highlighter should continue using (eg if you read the tokenSream in this method) or null to continue using the same TokenStream that was passed in.
        Throws:
        java.io.IOException - If there is a low-level I/O error

      • init

        private void init​(Query query,
                  java.lang.String field,
                  IndexReader reader,
                  boolean expandMultiTermQuery)

      • initExtractor

        private TokenStream initExtractor​(TokenStream tokenStream)
                           throws java.io.IOException
        Throws:
        java.io.IOException

      • startFragment

        public void startFragment​(TextFragment newFragment)
        Description copied from interface: Scorer
        Called when a new fragment is started for consideration.
        Specified by:
        startFragment in interface Scorer
        Parameters:
        newFragment - the fragment that will be scored next

      • isExpandMultiTermQuery

        public boolean isExpandMultiTermQuery()
        Returns:
        true if multi-term queries should be expanded

      • setExpandMultiTermQuery

        public void setExpandMultiTermQuery​(boolean expandMultiTermQuery)
        Controls whether or not multi-term queries are expanded against a MemoryIndex IndexReader.
        Parameters:
        expandMultiTermQuery - true if multi-term queries should be expanded

      • isUsePayloads

        public boolean isUsePayloads()
        Whether or not we should capture payloads in MemoryIndex at each position so that queries can access them. This does not apply to term vector based TokenStreams, which support payloads only when the term vector has them.

      • setUsePayloads

        public void setUsePayloads​(boolean usePayloads)

      • setWrapIfNotCachingTokenFilter

        public void setWrapIfNotCachingTokenFilter​(boolean wrap)
        By default, TokenStreams that are not of the type CachingTokenFilter are wrapped in a CachingTokenFilter to ensure an efficient reset - if you are already using a different caching TokenStream impl and you don't want it to be wrapped, set this to false. Note that term-vector based tokenstreams are detected and won't be wrapped either.

      • setMaxDocCharsToAnalyze

        public void setMaxDocCharsToAnalyze​(int maxDocCharsToAnalyze)