Class NGramPhraseQuery

  • public class NGramPhraseQuery
    extends Query
    This is a PhraseQuery which is optimized for n-gram phrase query. For example, when you query "ABCD" on a 2-gram field, you may want to use NGramPhraseQuery rather than PhraseQuery, because NGramPhraseQuery will rewrite(IndexReader) the query to "AB/0 CD/2", while PhraseQuery will query "AB/0 BC/1 CD/2" (where term/position).
    • Constructor Detail

    • Method Detail

      • 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.
        rewrite in class Query
      • equals

        public boolean equals(Object other)
        Description copied from class: Query
        Override and implement query instance equivalence properly in a subclass. This is required so that QueryCache works properly. Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical that other instance. Utility methods are provided for certain repetitive code.
        Specified by:
        equals in class Query
        See Also:
        Query.sameClassAs(Object), Query.classHash()
      • getN

        public int getN()
        Return the n in n-gram
      • getTerms

        public Term[] getTerms()
        Return the list of terms.
      • getPositions

        public int[] getPositions()
        Return the list of relative positions that each term should appear at.
      • 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.
        Specified by:
        toString in class Query