## org.apache.lucene.index
Class TermVectorMapper

    java.lang.Object
      org.apache.lucene.index.TermVectorMapper

Direct Known Subclasses:
  FieldSortedTermVectorMapper, PositionBasedTermVectorMapper, SortedTermVectorMapper

    public abstract class TermVectorMapper

extends Object

The TermVectorMapper can be used to map Term Vectors into your own structure instead of the parallel array structure used by `IndexReader.getTermFreqVector(int,String)`.

It is up to the implementation to make sure it is thread-safe.

Constructor Summary
`protected` `TermVectorMapper()`
`protected` `TermVectorMapper(boolean ignoringPositions, boolean ignoringOffsets)`

Method Summary
`boolean` `isIgnoringOffsets()`
`boolean` `isIgnoringPositions()` Indicate to Lucene that even if there are positions stored, this mapper is not interested in them and they can be skipped over.
`abstract void` `map(String term, int frequency, TermVectorOffsetInfo[] offsets, int[] positions)` Map the Term Vector information into your own structure
`void` `setDocumentNumber(int documentNumber)` Passes down the index of the document whose term vector is currently being mapped, once for each top level call to a term vector reader.
`abstract void` `setExpectations(String field, int numTerms, boolean storeOffsets, boolean storePositions)` Tell the mapper what to expect in regards to field, number of terms, offset and position storage.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### TermVectorMapper

    protected TermVectorMapper()

### TermVectorMapper

    protected TermVectorMapper(boolean ignoringPositions,
                               boolean ignoringOffsets)

Parameters:
  `ignoringPositions` - true if this mapper should tell Lucene to ignore positions even if they are stored
  `ignoringOffsets` - similar to ignoringPositions

Method Detail

### setExpectations

    public abstract void setExpectations(String field,
                                         int numTerms,
                                         boolean storeOffsets,
                                         boolean storePositions)

  Tell the mapper what to expect in regards to field, number of terms, offset and position storage. This method will be called once before retrieving the vector for a field. This method will be called before `map(String,int,TermVectorOffsetInfo[],int[])`.

  Parameters:
    `field` - The field the vector is for
    `numTerms` - The number of terms that need to be mapped
    `storeOffsets` - true if the mapper should expect offset information
    `storePositions` - true if the mapper should expect positions info

### map

    public abstract void map(String term,
                             int frequency,
                             TermVectorOffsetInfo[] offsets,
                             int[] positions)

  Map the Term Vector information into your own structure

  Parameters:
    `term` - The term to add to the vector
    `frequency` - The frequency of the term in the document
    `offsets` - null if the offset is not specified, otherwise the offset into the field of the term
    `positions` - null if the position is not specified, otherwise the position in the field of the term

### isIgnoringPositions

    public boolean isIgnoringPositions()

  Indicate to Lucene that even if there are positions stored, this mapper is not interested in them and they can be skipped over. Derived classes should set this to true if they want to ignore positions. The default is false, meaning positions will be loaded if they are stored.

  Returns:
    false

### isIgnoringOffsets

    public boolean isIgnoringOffsets()

  Returns:
    false
  See Also:
    `Same principal as {@link #isIgnoringPositions()}, but applied to offsets. false by default.`

### setDocumentNumber

    public void setDocumentNumber(int documentNumber)

  Passes down the index of the document whose term vector is currently being mapped, once for each top level call to a term vector reader.

  Default implementation IGNORES the document number. Override if your implementation needs the document number.

  NOTE: Document numbers are internal to Lucene and subject to change depending on indexing operations.

  Parameters:
    `documentNumber` - index of document currently being mapped

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