org.apache.lucene.index

Interface IndexableField

All Known Implementing Classes:

BinaryDocValuesField, ByteDocValuesField, DerefBytesDocValuesField, DoubleDocValuesField, DoubleField, Field, FloatDocValuesField, FloatField, IntDocValuesField, IntField, LongDocValuesField, LongField, NumericDocValuesField, PackedLongDocValuesField, ShortDocValuesField, SortedBytesDocValuesField, SortedDocValuesField, SortedNumericDocValuesField, SortedSetDocValuesField, StoredField, StraightBytesDocValuesField, StringField, TextField

public interface IndexableField

Represents a single field for indexing. IndexWriter consumes Iterable<IndexableField> as a document.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Method Summary

Methods

Modifier and Type	Method and Description
BytesRef	binaryValue() Non-null if this field has a binary value
float	boost() Returns the field's index-time boost.
IndexableFieldType	fieldType() IndexableFieldType describing the properties of this field.
String	name() Field name
Number	numericValue() Non-null if this field has a numeric value
Reader	readerValue() Non-null if this field has a Reader value
String	stringValue() Non-null if this field has a string value
TokenStream	tokenStream(Analyzer analyzer, TokenStream reuse) Creates the TokenStream used for indexing this field.

Method Detail

name

String name()

Field name

fieldType

IndexableFieldType fieldType()

IndexableFieldType describing the properties of this field.

boost

float boost()

Returns the field's index-time boost.

Only fields can have an index-time boost, if you want to simulate a "document boost", then you must pre-multiply it across all the relevant fields yourself.

The boost is used to compute the norm factor for the field. By default, in the Similarity.computeNorm(FieldInvertState) method, the boost value is multiplied by the length normalization factor and then rounded by DefaultSimilarity.encodeNormValue(float) before it is stored in the index. One should attempt to ensure that this product does not overflow the range of that encoding.

It is illegal to return a boost other than 1.0f for a field that is not indexed (IndexableFieldType.indexed() is false) or omits normalization values (IndexableFieldType.omitNorms() returns true).

See Also:

Similarity.computeNorm(FieldInvertState), DefaultSimilarity.encodeNormValue(float)

binaryValue

BytesRef binaryValue()

Non-null if this field has a binary value

stringValue

String stringValue()

Non-null if this field has a string value

readerValue

Reader readerValue()

Non-null if this field has a Reader value

numericValue

Number numericValue()

Non-null if this field has a numeric value

tokenStream

TokenStream tokenStream(Analyzer analyzer,
                      TokenStream reuse)
                        throws IOException

Creates the TokenStream used for indexing this field. If appropriate, implementations should use the given Analyzer to create the TokenStreams.

Parameters:

analyzer - Analyzer that should be used to create the TokenStreams from

reuse - TokenStream for a previous instance of this field name. This allows custom field types (like StringField and NumericField) that do not use the analyzer to still have good performance. Note: the passed-in type may be inappropriate, for example if you mix up different types of Fields for the same field name. So its the responsibility of the implementation to check.

Returns:

TokenStream value for indexing the document. Should always return a non-null value if the field is to be indexed

Throws:

IOException - Can be thrown while creating the TokenStream