org.apache.lucene.document

Class AbstractField

java.lang.Object

org.apache.lucene.document.AbstractField

All Implemented Interfaces:

java.io.Serializable, Fieldable

Direct Known Subclasses:

Field

public abstract class AbstractField
extends java.lang.Object
implements Fieldable

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
float	getBoost() Returns the boost factor for hits for this field.
boolean	getOmitNorms() True if norms are omitted for this indexed field
boolean	isBinary() True iff the value of the filed is stored as binary
boolean	isCompressed() True if the value of the field is stored and compressed within the index
boolean	isIndexed() True iff the value of the field is to be indexed, so that it may be searched on.
boolean	isLazy() Indicates whether a Field is Lazy or not.
boolean	isStored() True iff the value of the field is to be stored in the index for return with search hits.
boolean	isStoreOffsetWithTermVector() True iff terms are stored as term vector together with their offsets (start and end positon in source text).
boolean	isStorePositionWithTermVector() True iff terms are stored as term vector together with their token positions.
boolean	isTermVectorStored() True iff the term or terms used to index this field are stored as a term vector, available from IndexReader.getTermFreqVector(int,String).
boolean	isTokenized() True iff the value of the field should be tokenized as text prior to indexing.
java.lang.String	name() Returns the name of the field as an interned string.
void	setBoost(float boost) Sets the boost factor hits on this field.
void	setOmitNorms(boolean omitNorms) Expert: If set, omit normalization factors associated with this indexed field.
java.lang.String	toString() Prints a Field for human consumption.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.lucene.document.Fieldable

binaryValue, readerValue, stringValue, tokenStreamValue

Method Detail

setBoost

public void setBoost(float boost)

Sets the boost factor hits on this field. This value will be multiplied into the score of all hits on this this field of this document.

The boost is multiplied by 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 multipled by the value Similarity.lengthNorm(String,int), and rounded by Similarity.encodeNorm(float) before it is stored in the index. One should attempt to ensure that this product does not overflow the range of that encoding.

Specified by:

setBoost in interface Fieldable

See Also:

Document.setBoost(float), Similarity.lengthNorm(String, int), Similarity.encodeNorm(float)

getBoost

public float getBoost()

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 IndexReader.document(int) and Hits.doc(int) may thus not have the same value present as when this field was indexed.

Specified by:

getBoost in interface Fieldable

See Also:

setBoost(float)

name

public java.lang.String name()

Returns the name of the field as an interned string. For example "date", "title", "body", ...

Specified by:

name in interface Fieldable

isStored

public final boolean isStored()

True iff the value of the field is to be stored in the index for return with search hits. It is an error for this to be true if a field is Reader-valued.

Specified by:

isStored in interface Fieldable

isIndexed

public final boolean isIndexed()

True iff the value of the field is to be indexed, so that it may be searched on.

Specified by:

isIndexed in interface Fieldable

isTokenized

public final boolean isTokenized()

True iff 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.

Specified by:

isTokenized in interface Fieldable

isCompressed

public final boolean isCompressed()

True if the value of the field is stored and compressed within the index

Specified by:

isCompressed in interface Fieldable

isTermVectorStored

public final boolean isTermVectorStored()

True iff the term or terms used to index this field are stored as a term vector, available from 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.

Specified by:

isTermVectorStored in interface Fieldable

See Also:

IndexReader.getTermFreqVector(int, String)

isStoreOffsetWithTermVector

public boolean isStoreOffsetWithTermVector()

True iff terms are stored as term vector together with their offsets (start and end positon in source text).

Specified by:

isStoreOffsetWithTermVector in interface Fieldable

isStorePositionWithTermVector

public boolean isStorePositionWithTermVector()

True iff terms are stored as term vector together with their token positions.

Specified by:

isStorePositionWithTermVector in interface Fieldable

isBinary

public final boolean isBinary()

True iff the value of the filed is stored as binary

Specified by:

isBinary in interface Fieldable

getOmitNorms

public boolean getOmitNorms()

True if norms are omitted for this indexed field

Specified by:

getOmitNorms in interface Fieldable

setOmitNorms

public void setOmitNorms(boolean omitNorms)

Expert: If set, omit normalization factors associated with this indexed field. This effectively disables indexing boosts and length normalization for this field.

Specified by:

setOmitNorms in interface Fieldable

isLazy

public boolean isLazy()

Description copied from interface: Fieldable

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 Fieldable.stringValue() or Fieldable.binaryValue() is only valid as long as the IndexReader that retrieved the Document is still open.

Specified by:

isLazy in interface Fieldable

Returns:

true if this field can be loaded lazily

toString

public final java.lang.String toString()

Prints a Field for human consumption.

Overrides:

toString in class java.lang.Object