org.apache.lucene.document
Class Field

java.lang.Object
  org.apache.lucene.document.AbstractField
      org.apache.lucene.document.Field

All Implemented Interfaces:

Serializable, Fieldable

public final class Field
extends AbstractField
implements Fieldable, Serializable

A field is a section of a Document. Each field has two parts, a name and a value. Values may be free text, provided as a String or as a Reader, or they may be atomic keywords, which are not further processed. Such keywords may be used to represent dates, urls, etc. Fields are optionally stored in the index, so that they may be returned with hits on the document.

See Also:

Serialized Form

Nested Class Summary

static class	Field.Index Specifies whether and how a field should be indexed.
static class	Field.Store Specifies whether and how a field should be stored.
static class	Field.TermVector Specifies whether and how a field should have term vectors.

Field Summary

Fields inherited from class org.apache.lucene.document.AbstractField

binaryLength, binaryOffset, boost, fieldsData, isBinary, isCompressed, isIndexed, isStored, isTokenized, lazy, name, omitNorms, omitTf, storeOffsetWithTermVector, storePositionWithTermVector, storeTermVector

Constructor Summary

Field(String name, byte[] value, Field.Store store)
Create a stored field with binary value.

Field(String name, byte[] value, int offset, int length, Field.Store store)
Create a stored field with binary value.

Field(String name, Reader reader)
Create a tokenized and indexed field that is not stored.

Field(String name, Reader reader, Field.TermVector termVector)
Create a tokenized and indexed field that is not stored, optionally with storing term vectors.

Field(String name, String value, Field.Store store, Field.Index index)
Create a field by specifying its name, value and how it will be saved in the index.

Field(String name, String value, Field.Store store, Field.Index index, Field.TermVector termVector)
Create a field by specifying its name, value and how it will be saved in the index.

Field(String name, TokenStream tokenStream)
Create a tokenized and indexed field that is not stored.

Field(String name, TokenStream tokenStream, Field.TermVector termVector)
Create a tokenized and indexed field that is not stored, optionally with storing term vectors.

Method Summary

byte[]	binaryValue() Deprecated. This method must allocate a new byte[] if the AbstractField.getBinaryOffset() is non-zero or AbstractField.getBinaryLength() is not the full length of the byte[]. Please use AbstractField.getBinaryValue() instead, which simply returns the byte[].
Reader	readerValue() The value of the field as a Reader, or null.
void	setValue(byte[] value) Expert: change the value of this field.
void	setValue(byte[] value, int offset, int length) Expert: change the value of this field.
void	setValue(Reader value) Expert: change the value of this field.
void	setValue(String value) Expert: change the value of this field.
void	setValue(TokenStream value) Expert: change the value of this field.
String	stringValue() The value of the field as a String, or null.
TokenStream	tokenStreamValue() The value of the field as a TokesStream, or null.

Methods inherited from class org.apache.lucene.document.AbstractField

getBinaryLength, getBinaryOffset, getBinaryValue, getBinaryValue, getBoost, getOmitNorms, getOmitTf, isBinary, isCompressed, isIndexed, isLazy, isStored, isStoreOffsetWithTermVector, isStorePositionWithTermVector, isTermVectorStored, isTokenized, name, setBoost, setOmitNorms, setOmitTf, setStoreTermVector, toString

Methods inherited from class java.lang.Object

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

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

getBinaryLength, getBinaryOffset, getBinaryValue, getBinaryValue, getBoost, getOmitNorms, getOmitTf, isBinary, isCompressed, isIndexed, isLazy, isStored, isStoreOffsetWithTermVector, isStorePositionWithTermVector, isTermVectorStored, isTokenized, name, setBoost, setOmitNorms, setOmitTf

Constructor Detail

Field

public Field(String name,
             String value,
             Field.Store store,
             Field.Index index)

Create a field by specifying its name, value and how it will be saved in the index. Term vectors will not be stored in the index.

Parameters:

name - The name of the field

value - The string to process

store - Whether value should be stored in the index

index - Whether the field should be indexed, and if so, if it should be tokenized before indexing

Throws:

NullPointerException - if name or value is null

IllegalArgumentException - if the field is neither stored nor indexed

Field

public Field(String name,
             String value,
             Field.Store store,
             Field.Index index,
             Field.TermVector termVector)

Create a field by specifying its name, value and how it will be saved in the index.

Parameters:

name - The name of the field

value - The string to process

store - Whether value should be stored in the index

index - Whether the field should be indexed, and if so, if it should be tokenized before indexing

termVector - Whether term vector should be stored

Throws:

NullPointerException - if name or value is null

IllegalArgumentException - in any of the following situations:

• the field is neither stored nor indexed
• the field is not indexed but termVector is TermVector.YES

Field

public Field(String name,
             Reader reader)

Create a tokenized and indexed field that is not stored. Term vectors will not be stored. The Reader is read only when the Document is added to the index, i.e. you may not close the Reader until IndexWriter.addDocument(Document) has been called.

Parameters:

name - The name of the field

reader - The reader with the content

Throws:

NullPointerException - if name or reader is null

Field

public Field(String name,
             Reader reader,
             Field.TermVector termVector)

Create a tokenized and indexed field that is not stored, optionally with storing term vectors. The Reader is read only when the Document is added to the index, i.e. you may not close the Reader until IndexWriter.addDocument(Document) has been called.

Parameters:

name - The name of the field

reader - The reader with the content

termVector - Whether term vector should be stored

Throws:

NullPointerException - if name or reader is null

Field

public Field(String name,
             TokenStream tokenStream)

Create a tokenized and indexed field that is not stored. Term vectors will not be stored. This is useful for pre-analyzed fields. The TokenStream is read only when the Document is added to the index, i.e. you may not close the TokenStream until IndexWriter.addDocument(Document) has been called.

Parameters:

name - The name of the field

tokenStream - The TokenStream with the content

Throws:

NullPointerException - if name or tokenStream is null

Field

public Field(String name,
             TokenStream tokenStream,
             Field.TermVector termVector)

Create a tokenized and indexed field that is not stored, optionally with storing term vectors. This is useful for pre-analyzed fields. The TokenStream is read only when the Document is added to the index, i.e. you may not close the TokenStream until IndexWriter.addDocument(Document) has been called.

Parameters:

name - The name of the field

tokenStream - The TokenStream with the content

termVector - Whether term vector should be stored

Throws:

NullPointerException - if name or tokenStream is null

Field

public Field(String name,
             byte[] value,
             Field.Store store)

Create a stored field with binary value. Optionally the value may be compressed.

Parameters:

name - The name of the field

value - The binary value

store - How value should be stored (compressed or not)

Throws:

IllegalArgumentException - if store is Store.NO

Field

public Field(String name,
             byte[] value,
             int offset,
             int length,
             Field.Store store)

Create a stored field with binary value. Optionally the value may be compressed.

Parameters:

name - The name of the field

value - The binary value

offset - Starting offset in value where this Field's bytes are

length - Number of bytes to use for this Field, starting at offset

store - How value should be stored (compressed or not)

Throws:

IllegalArgumentException - if store is Store.NO

Method Detail

stringValue

public String stringValue()

The value of the field as a String, or null. If null, the Reader value, binary value, or TokenStream value is used. Exactly one of stringValue(), readerValue(), getBinaryValue(), and tokenStreamValue() must be set.

Specified by:

stringValue in interface Fieldable

readerValue

public Reader readerValue()

The value of the field as a Reader, or null. If null, the String value, binary value, or TokenStream value is used. Exactly one of stringValue(), readerValue(), getBinaryValue(), and tokenStreamValue() must be set.

Specified by:

readerValue in interface Fieldable

binaryValue

public byte[] binaryValue()

Deprecated. This method must allocate a new byte[] if the AbstractField.getBinaryOffset() is non-zero or AbstractField.getBinaryLength() is not the full length of the byte[]. Please use AbstractField.getBinaryValue() instead, which simply returns the byte[].

The value of the field in Binary, or null. If null, the Reader value, String value, or TokenStream value is used. Exactly one of stringValue(), readerValue(), getBinaryValue(), and tokenStreamValue() must be set.

Specified by:

binaryValue in interface Fieldable

tokenStreamValue

public TokenStream tokenStreamValue()

The value of the field as a TokesStream, or null. If null, the Reader value, String value, or binary value is used. Exactly one of stringValue(), readerValue(), getBinaryValue(), and tokenStreamValue() must be set.

Specified by:

tokenStreamValue in interface Fieldable

setValue

public void setValue(String value)

Expert: change the value of this field. This can be used during indexing to re-use a single Field instance to improve indexing speed by avoiding GC cost of new'ing and reclaiming Field instances. Typically a single Document instance is re-used as well. This helps most on small documents.

Note that you should only use this method after the Field has been consumed (ie, the Document containing this Field has been added to the index). Also, each Field instance should only be used once within a single Document instance. See ImproveIndexingSpeed for details.

setValue

public void setValue(Reader value)

Expert: change the value of this field. See setValue(String).

setValue

public void setValue(byte[] value)

Expert: change the value of this field. See setValue(String).

setValue

public void setValue(byte[] value,
                     int offset,
                     int length)

Expert: change the value of this field. See setValue(String).

setValue

public void setValue(TokenStream value)

Expert: change the value of this field. See setValue(String).