Package org.apache.lucene.index

Class TermVectors

java.lang.Object
org.apache.lucene.index.TermVectors
Direct Known Subclasses:
TermVectorsReader
public abstract class TermVectors extends Object
API for reading term vectors.

NOTE: This class is not thread-safe and should only be consumed in the thread where it was acquired.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final TermVectors
    EMPTY
    Instance that never returns term vectors

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    TermVectors()
    Sole constructor.

  • Method Summary

    Modifier and Type
    Method
    Description
    abstract Fields
    get(int doc)
    Returns term vectors for this document, or null if term vectors were not indexed.
    final Terms
    get(int doc, String field)
    Retrieve term vector for this document and field, or null if term vectors were not indexed.
    void
    prefetch(int docID)
    Optional method: Give a hint to this TermVectors instance that the given document will be read in the near future.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • EMPTY

      public static final TermVectors EMPTY
      Instance that never returns term vectors

  • Constructor Details

    • TermVectors

      protected TermVectors()
      Sole constructor. (For invocation by subclass constructors, typically implicit.)

  • Method Details

    • prefetch

      public void prefetch(int docID) throws IOException
      Optional method: Give a hint to this TermVectors instance that the given document will be read in the near future. This typically delegates to IndexInput.prefetch(long, long) and is useful to parallelize I/O across multiple documents.

      NOTE: This API is expected to be called on a small enough set of doc IDs that they could all fit in the page cache. If you plan on retrieving a very large number of documents, it may be a good idea to perform calls to prefetch(int) and get(int) in batches instead of prefetching all documents up-front.

      Throws:
      IOException

    • get

      public abstract Fields get(int doc) throws IOException
      Returns term vectors for this document, or null if term vectors were not indexed.

      The returned Fields instance acts like a single-document inverted index (the docID will be 0). If offsets are available they are in an OffsetAttribute available from the PostingsEnum.

      Throws:
      IOException

    • get

      public final Terms get(int doc, String field) throws IOException
      Retrieve term vector for this document and field, or null if term vectors were not indexed.

      The returned Terms instance acts like a single-document inverted index (the docID will be 0). If offsets are available they are in an OffsetAttribute available from the PostingsEnum.

      Throws:
      IOException