Class Fields

java.lang.Object
org.apache.lucene.index.Fields
All Implemented Interfaces:
Iterable<String>
Direct Known Subclasses:
FieldsProducer, FilterAtomicReader.FilterFields, MultiFields

public abstract class Fields extends Object implements Iterable<String>
Flex API for access to fields and terms
  • Field Details

    • EMPTY_ARRAY

      public static final Fields[] EMPTY_ARRAY
      Zero-length Fields array.
  • Constructor Details

    • Fields

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

    • iterator

      public abstract Iterator<String> iterator()
      Returns an iterator that will step through all fields names. This will not return null.
      Specified by:
      iterator in interface Iterable<String>
    • terms

      public abstract Terms terms(String field) throws IOException
      Get the Terms for this field. This will return null if the field does not exist.
      Throws:
      IOException
    • size

      public abstract int size()
      Returns the number of fields or -1 if the number of distinct field names is unknown. If >= 0, iterator() will return as many field names.
    • getUniqueTermCount

      @Deprecated public long getUniqueTermCount() throws IOException
      Deprecated.
      iterate fields and add their size() instead. this method is only provided as a transition mechanism to access this statistic for 3.x indexes, which do not have this statistic per-field.
      Returns the number of terms for all fields, 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
      See Also: