Class Terms

    • Field Detail

      • EMPTY_ARRAY

        public static final Terms[] EMPTY_ARRAY
        Zero-length array of Terms.
    • Constructor Detail

      • Terms

        protected Terms()
        Sole constructor. (For invocation by subclass constructors, typically implicit.)
    • Method Detail

      • getTerms

        public static Terms getTerms​(LeafReader reader,
                                     String field)
                              throws IOException
        Returns the Terms index for this field, or EMPTY if it has none.
        Returns:
        terms instance, or an empty instance if field does not exist in this reader
        Throws:
        IOException - if an I/O error occurs.
      • iterator

        public abstract TermsEnum iterator()
                                    throws IOException
        Returns an iterator that will step through all terms. This method will not return null.
        Throws:
        IOException
      • intersect

        public TermsEnum intersect​(CompiledAutomaton compiled,
                                   BytesRef startTerm)
                            throws IOException
        Returns a TermsEnum that iterates over all terms and documents that are accepted by the provided CompiledAutomaton. If the startTerm is provided then the returned enum will only return terms > startTerm, but you still must call next() first to get to the first term. Note that the provided startTerm must be accepted by the automaton.

        This is an expert low-level API and will only work for NORMAL compiled automata. To handle any compiled automata you should instead use CompiledAutomaton.getTermsEnum(org.apache.lucene.index.Terms) instead.

        NOTE: the returned TermsEnum cannot seek.

        Throws:
        IOException
      • size

        public abstract long size()
                           throws IOException
        Returns the number of terms for this field, or -1 if this measure isn't stored by the codec. Note that, just like other term measures, this measure does not take deleted documents into account.
        Throws:
        IOException
      • getSumTotalTermFreq

        public abstract long getSumTotalTermFreq()
                                          throws IOException
        Returns the sum of TermsEnum.totalTermFreq() for all terms in this field. Note that, just like other term measures, this measure does not take deleted documents into account.
        Throws:
        IOException
      • getSumDocFreq

        public abstract long getSumDocFreq()
                                    throws IOException
        Returns the sum of TermsEnum.docFreq() for all terms in this field. Note that, just like other term measures, this measure does not take deleted documents into account.
        Throws:
        IOException
      • getDocCount

        public abstract int getDocCount()
                                 throws IOException
        Returns the number of documents that have at least one term for this field. Note that, just like other term measures, this measure does not take deleted documents into account.
        Throws:
        IOException
      • hasFreqs

        public abstract boolean hasFreqs()
        Returns true if documents in this field store per-document term frequency (PostingsEnum.freq()).
      • hasOffsets

        public abstract boolean hasOffsets()
        Returns true if documents in this field store offsets.
      • hasPositions

        public abstract boolean hasPositions()
        Returns true if documents in this field store positions.
      • hasPayloads

        public abstract boolean hasPayloads()
        Returns true if documents in this field store payloads.
      • getMin

        public BytesRef getMin()
                        throws IOException
        Returns the smallest term (in lexicographic order) in the field. Note that, just like other term measures, this measure does not take deleted documents into account. This returns null when there are no terms.
        Throws:
        IOException
      • getMax

        public BytesRef getMax()
                        throws IOException
        Returns the largest term (in lexicographic order) in the field. Note that, just like other term measures, this measure does not take deleted documents into account. This returns null when there are no terms.
        Throws:
        IOException
      • getStats

        public Object getStats()
                        throws IOException
        Expert: returns additional information about this Terms instance for debugging purposes.
        Throws:
        IOException