The boost is multiplied by {@link org.apache.lucene.document.Document#getBoost()} of the document * containing this field. If a document has multiple fields with the same * name, all such values are multiplied together. This product is then * used to compute the norm factor for the field. By * default, in the {@link * org.apache.lucene.search.Similarity#computeNorm(String, * FieldInvertState)} method, the boost value is multiplied * by the {@link * org.apache.lucene.search.Similarity#lengthNorm(String, * int)} and then rounded by {@link org.apache.lucene.search.Similarity#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. * * @see org.apache.lucene.document.Document#setBoost(float) * @see org.apache.lucene.search.Similarity#computeNorm(String, FieldInvertState) * @see org.apache.lucene.search.Similarity#encodeNormValue(float) */ void setBoost(float boost); /** Returns the boost factor for hits for this field. * *
The default value is 1.0. * *
Note: this value is not stored directly with the document in the index. * Documents returned from {@link org.apache.lucene.index.IndexReader#document(int)} and * {@link org.apache.lucene.search.Searcher#doc(int)} may thus not have the same value present as when * this field was indexed. * * @see #setBoost(float) */ float getBoost(); /** Returns the name of the field as an interned string. * For example "date", "title", "body", ... */ String name(); /** The value of the field as a String, or null. *
* For indexing, if isStored()==true, the stringValue() will be used as the stored field value
* unless isBinary()==true, in which case getBinaryValue() will be used.
*
* If isIndexed()==true and isTokenized()==false, this String value will be indexed as a single token.
* If isIndexed()==true and isTokenized()==true, then tokenStreamValue() will be used to generate indexed tokens if not null,
* else readerValue() will be used to generate indexed tokens if not null, else stringValue() will be used to generate tokens.
*/
public String stringValue();
/** The value of the field as a Reader, which can be used at index time to generate indexed tokens.
* @see #stringValue()
*/
public Reader readerValue();
/** The TokenStream for this field to be used when indexing, or null.
* @see #stringValue()
*/
public TokenStream tokenStreamValue();
/** True if the value of the field is to be stored in the index for return
with search hits. */
boolean isStored();
/** True if the value of the field is to be indexed, so that it may be
searched on. */
boolean isIndexed();
/** True if the value of the field should be tokenized as text prior to
indexing. Un-tokenized fields are indexed as a single word and may not be
Reader-valued. */
boolean isTokenized();
/** True if the term or terms used to index this field are stored as a term
* vector, available from {@link org.apache.lucene.index.IndexReader#getTermFreqVector(int,String)}.
* These methods do not provide access to the original content of the field,
* only to terms used to index it. If the original content must be
* preserved, use the stored attribute instead.
*
* @see org.apache.lucene.index.IndexReader#getTermFreqVector(int, String)
*/
boolean isTermVectorStored();
/**
* True if terms are stored as term vector together with their offsets
* (start and end positon in source text).
*/
boolean isStoreOffsetWithTermVector();
/**
* True if terms are stored as term vector together with their token positions.
*/
boolean isStorePositionWithTermVector();
/** True if the value of the field is stored as binary */
boolean isBinary();
/** True if norms are omitted for this indexed field */
boolean getOmitNorms();
/** Expert:
*
* If set, omit normalization factors associated with this indexed field.
* This effectively disables indexing boosts and length normalization for this field.
*/
void setOmitNorms(boolean omitNorms);
/**
* Indicates whether a Field is Lazy or not. The semantics of Lazy loading are such that if a Field is lazily loaded, retrieving
* it's values via {@link #stringValue()} or {@link #getBinaryValue()} is only valid as long as the {@link org.apache.lucene.index.IndexReader} that
* retrieved the {@link Document} is still open.
*
* @return true if this field can be loaded lazily
*/
boolean isLazy();
/**
* Returns offset into byte[] segment that is used as value, if Field is not binary
* returned value is undefined
* @return index of the first character in byte[] segment that represents this Field value
*/
abstract int getBinaryOffset();
/**
* Returns length of byte[] segment that is used as value, if Field is not binary
* returned value is undefined
* @return length of byte[] segment that represents this Field value
*/
abstract int getBinaryLength();
/**
* Return the raw byte[] for the binary field. Note that
* you must also call {@link #getBinaryLength} and {@link
* #getBinaryOffset} to know which range of bytes in this
* returned array belong to the field.
* @return reference to the Field value as byte[].
*/
abstract byte[] getBinaryValue();
/**
* Return the raw byte[] for the binary field. Note that
* you must also call {@link #getBinaryLength} and {@link
* #getBinaryOffset} to know which range of bytes in this
* returned array belong to the field.
* About reuse: if you pass in the result byte[] and it is * used, likely the underlying implementation will hold * onto this byte[] and return it in future calls to * {@link #getBinaryValue()}. * So if you subsequently re-use the same byte[] elsewhere * it will alter this Fieldable's value. * @param result User defined buffer that will be used if * possible. If this is null or not large enough, a new * buffer is allocated * @return reference to the Field value as byte[]. */ abstract byte[] getBinaryValue(byte[] result); /** @see #setOmitTermFreqAndPositions */ boolean getOmitTermFreqAndPositions(); /** Expert: * * If set, omit term freq, positions and payloads from * postings for this field. * *
NOTE: While this option reduces storage space * required in the index, it also means any query * requiring positional information, such as {@link * PhraseQuery} or {@link SpanQuery} subclasses will * silently fail to find results. */ void setOmitTermFreqAndPositions(boolean omitTermFreqAndPositions); }