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. More...

Inherits Lucene.Net.Documents.AbstractField, and Lucene.Net.Documents.IFieldable.

Public Types
enum	Store { YES, NO }
	Specifies whether and how a field should be stored. More...

enum	Index { NO, ANALYZED, NOT_ANALYZED, NOT_ANALYZED_NO_NORMS, ANALYZED_NO_NORMS }
	Specifies whether and how a field should be indexed. More...

enum	TermVector { NO, YES, WITH_POSITIONS, WITH_OFFSETS, WITH_POSITIONS_OFFSETS }
	Specifies whether and how a field should have term vectors. More...

Public Member Functions
void	SetValue (System.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.

void	SetValue (System.IO.TextReader value)
	Expert: change the value of this field. See setValue(String).

void	SetValue (byte[] value)
	Expert: change the value of this field. See setValue(String).

void	SetValue (byte[] value, int offset, int length)
	Expert: change the value of this field. See setValue(String).

void	SetTokenStream (TokenStream tokenStream)
	Expert: sets the token stream to be used for indexing and causes isIndexed() and isTokenized() to return true. May be combined with stored values from stringValue() or GetBinaryValue()

	Field (System.String name, System.String value, Store store, 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.

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

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

	Field (System.String name, System.IO.TextReader 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.

	Field (System.String name, System.IO.TextReader reader, 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.

	Field (System.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.

	Field (System.String name, TokenStream tokenStream, 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.

	Field (System.String name, byte[] value_Renamed, Store store)
	Create a stored field with binary value. Optionally the value may be compressed.

	Field (System.String name, byte[] value_Renamed, int offset, int length, Store store)
	Create a stored field with binary value. Optionally the value may be compressed.

Public Member Functions inherited from Lucene.Net.Documents.AbstractField
virtual byte[]	GetBinaryValue ()
	Return the raw byte[] for the binary field. Note that you must also call BinaryLength and BinaryOffset to know which range of bytes in this returned array belong to the field.

virtual byte[]	GetBinaryValue (byte[] result)
	Return the raw byte[] for the binary field. Note that you must also call BinaryLength and BinaryOffset 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 GetBinaryValue() or GetBinaryValue(). So if you subsequently re-use the same byte[] elsewhere it will alter this Fieldable's value.

override System.String	ToString ()
	Prints a Field for human consumption.

Properties
override string	StringValue `[get]`
	The value of the field as a String, or null. If null, the Reader value or binary value is used. Exactly one of stringValue(), readerValue(), and getBinaryValue() must be set.

override TextReader	ReaderValue `[get]`
	The value of the field as a Reader, or null. If null, the String value or binary value is used. Exactly one of stringValue(), readerValue(), and getBinaryValue() must be set.

override TokenStream	TokenStreamValue `[get]`
	The TokesStream for this field to be used when indexing, or null. If null, the Reader value or String value is analyzed to produce the indexed tokens.

Properties inherited from Lucene.Net.Documents.AbstractField
virtual float	Boost `[get, set]`
	Gets or sets the boost factor for hits for this field.

virtual string	Name `[get]`
	Returns the name of the field as an interned string. For example "date", "title", "body", ...

bool	IsStored `[get]`
	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.

bool	IsIndexed `[get]`
	True iff the value of the field is to be indexed, so that it may be searched on.

bool	IsTokenized `[get]`
	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.

bool	IsTermVectorStored `[get]`
	True iff the term or terms used to index this field are stored as a term vector, available from Lucene.Net.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.

virtual bool	IsStoreOffsetWithTermVector `[get]`
	True iff terms are stored as term vector together with their offsets (start and end position in source text).

virtual bool	IsStorePositionWithTermVector `[get]`
	True iff terms are stored as term vector together with their token positions.

bool	IsBinary `[get]`
	True iff the value of the filed is stored as binary

virtual int	BinaryLength `[get]`
	Returns length of byte[] segment that is used as value, if Field is not binary returned value is undefined

virtual int	BinaryOffset `[get]`
	Returns offset into byte[] segment that is used as value, if Field is not binary returned value is undefined

virtual bool	OmitNorms `[get, set]`
	True if norms are omitted for this indexed field

virtual bool	OmitTermFreqAndPositions `[get, set]`
	Expert:

virtual bool	IsLazy `[get]`

abstract TokenStream	TokenStreamValue `[get]`

abstract TextReader	ReaderValue `[get]`

abstract string	StringValue `[get]`

Properties inherited from Lucene.Net.Documents.IFieldable
float	Boost `[get, set]`
	Gets or sets the boost factor for hits for this field. This value will be multiplied into the score of all hits on this this field of this document.

string	Name `[get]`
	Returns the name of the field as an interned string. For example "date", "title", "body", ...

string	StringValue `[get]`
	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.

TextReader	ReaderValue `[get]`
	The value of the field as a Reader, which can be used at index time to generate indexed tokens.

TokenStream	TokenStreamValue `[get]`
	The TokenStream for this field to be used when indexing, or null.

bool	IsStored `[get]`
	True if the value of the field is to be stored in the index for return with search hits.

bool	IsIndexed `[get]`
	True if the value of the field is to be indexed, so that it may be searched on.

bool	IsTokenized `[get]`
	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.

bool	IsTermVectorStored `[get]`
	True if the term or terms used to index this field are stored as a term vector, available from Lucene.Net.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.

bool	IsStoreOffsetWithTermVector `[get]`
	True if terms are stored as term vector together with their offsets (start and end positon in source text).

bool	IsStorePositionWithTermVector `[get]`
	True if terms are stored as term vector together with their token positions.

bool	IsBinary `[get]`
	True if the value of the field is stored as binary

bool	OmitNorms `[get, set]`
	True if norms are omitted for this indexed field.

bool	IsLazy `[get]`
	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 StringValue() or GetBinaryValue() is only valid as long as the Lucene.Net.Index.IndexReader that retrieved the Document is still open.

int	BinaryOffset `[get]`
	Returns offset into byte[] segment that is used as value, if Field is not binary returned value is undefined

int	BinaryLength `[get]`
	Returns length of byte[] segment that is used as value, if Field is not binary returned value is undefined

bool	OmitTermFreqAndPositions `[get, set]`

Detailed Description

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.

Definition at line 35 of file Field.cs.

Member Enumeration Documentation

enum Lucene.Net.Documents.Field.Index

Specifies whether and how a field should be indexed.

Enumerator
NO	Do not index the field value. This field can thus not be searched, but one can still access its contents provided it is stored.
ANALYZED	Index the tokens produced by running the field's value through an Analyzer. This is useful for common text.
NOT_ANALYZED	Index the field's value without using an Analyzer, so it can be searched. As no analyzer is used the value will be stored as a single term. This is useful for unique Ids like product numbers.
NOT_ANALYZED_NO_NORMS	Expert: Index the field's value without an Analyzer, and also disable the storing of norms. Note that you can also separately enable/disable norms by setting AbstractField.OmitNorms. No norms means that index-time field and document boosting and field length normalization are disabled. The benefit is less memory usage as norms take up one byte of RAM per indexed field for every document in the index, during searching. Note that once you index a given field with norms enabled, disabling norms will have no effect. In other words, for this to have the above described effect on a field, all instances of that field must be indexed with NOT_ANALYZED_NO_NORMS from the beginning.
ANALYZED_NO_NORMS	Expert: Index the tokens produced by running the field's value through an Analyzer, and also separately disable the storing of norms. See NOT_ANALYZED_NO_NORMS for what norms are and why you may want to disable them.

Definition at line 53 of file Field.cs.

enum Lucene.Net.Documents.Field.Store

Specifies whether and how a field should be stored.

Enumerator
YES	Store the original field value in the index. This is useful for short texts like a document's title which should be displayed with the results. The value is stored in its original form, i.e. no analyzer is used before it is stored.
NO	Do not store the field value in the index.

Definition at line 38 of file Field.cs.

enum Lucene.Net.Documents.Field.TermVector

Specifies whether and how a field should have term vectors.

Enumerator
NO	Do not store term vectors.
YES	Store the term vectors of each document. A term vector is a list of the document's terms and their number of occurrences in that document.
WITH_POSITIONS	Store the term vector + token position information See Also YES
WITH_OFFSETS	Store the term vector + Token offset information See Also YES
WITH_POSITIONS_OFFSETS	Store the term vector + Token position and offset information See Also YES See Also WITH_POSITIONS See Also WITH_OFFSETS

Definition at line 100 of file Field.cs.

Constructor & Destructor Documentation

Lucene.Net.Documents.Field.Field	(	System.String	name,
		System.String	value,
		Store	store,
		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 </throws> <throws> IllegalArgumentException if the field is neither stored nor indexed </throws>

Definition at line 248 of file Field.cs.

Lucene.Net.Documents.Field.Field	(	System.String	name,
		System.String	value,
		Store	store,
		Index	index,
		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 </throws> <throws> IllegalArgumentException in any of the following situations: </throws>

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

Definition at line 275 of file Field.cs.

Lucene.Net.Documents.Field.Field	(	System.String	name,
		bool	internName,
		System.String	value,
		Store	store,
		Index	index,
		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
internName	Whether to .intern() name or not
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 </throws> <throws> IllegalArgumentException in any of the following situations: </throws>

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

Definition at line 304 of file Field.cs.

Lucene.Net.Documents.Field.Field	(	System.String	name,
		System.IO.TextReader	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 </throws>

Definition at line 352 of file Field.cs.

Lucene.Net.Documents.Field.Field	(	System.String	name,
		System.IO.TextReader	reader,
		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 </throws>

Definition at line 369 of file Field.cs.

Lucene.Net.Documents.Field.Field	(	System.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 </throws>

Definition at line 401 of file Field.cs.

Lucene.Net.Documents.Field.Field	(	System.String	name,
		TokenStream	tokenStream,
		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 </throws>

Definition at line 419 of file Field.cs.

Lucene.Net.Documents.Field.Field	(	System.String	name,
		byte[]	value_Renamed,
		Store	store
	)

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

Parameters

name	The name of the field
value_Renamed	The binary value
store	How `value` should be stored (compressed or not)

<throws> IllegalArgumentException if store is Store.NO </throws>

Definition at line 451 of file Field.cs.

Lucene.Net.Documents.Field.Field	(	System.String	name,
		byte[]	value_Renamed,
		int	offset,
		int	length,
		Store	store
	)

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

Parameters

name	The name of the field
value_Renamed	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 </throws>

Definition at line 469 of file Field.cs.

Member Function Documentation

void Lucene.Net.Documents.Field.SetTokenStream ( TokenStream tokenStream )

Expert: sets the token stream to be used for indexing and causes isIndexed() and isTokenized() to return true. May be combined with stored values from stringValue() or GetBinaryValue()

Definition at line 226 of file Field.cs.

void Lucene.Net.Documents.Field.SetValue ( System.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.

Each Field instance should only be used once within a single Document instance. See ImproveIndexingSpeed for details.

Definition at line 176 of file Field.cs.

void Lucene.Net.Documents.Field.SetValue ( System.IO.TextReader value )

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

Definition at line 186 of file Field.cs.

void Lucene.Net.Documents.Field.SetValue ( byte[] value )

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

Definition at line 200 of file Field.cs.

void Lucene.Net.Documents.Field.SetValue	(	byte[]	value,
		int	offset,
		int	length
	)

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

Definition at line 212 of file Field.cs.

Property Documentation

override TextReader Lucene.Net.Documents.Field.ReaderValue

get

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

Definition at line 151 of file Field.cs.

override string Lucene.Net.Documents.Field.StringValue

get

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

Definition at line 142 of file Field.cs.

override TokenStream Lucene.Net.Documents.Field.TokenStreamValue

get

The TokesStream for this field to be used when indexing, or null. If null, the Reader value or String value is analyzed to produce the indexed tokens.

Definition at line 159 of file Field.cs.

The documentation for this class was generated from the following file:

core/Document/Field.cs

Public Types

Public Member Functions

Properties

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Property Documentation