public final class

Field

extends AbstractField
implements Serializable Fieldable
java.lang.Object
   ↳ org.apache.lucene.document.AbstractField
     ↳ org.apache.lucene.document.Field

Class Overview

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.

Summary

Nested Classes
enum Field.Index Specifies whether and how a field should be indexed. 
enum Field.Store Specifies whether and how a field should be stored. 
enum Field.TermVector Specifies whether and how a field should have term vectors. 
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Inherited Fields
From class org.apache.lucene.document.AbstractField
Public Constructors
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, boolean internName, 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, 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, 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.
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.
Public Methods
Reader readerValue()
The value of the field as a Reader, or null.
void setTokenStream(TokenStream tokenStream)
Expert: sets the token stream to be used for indexing and causes isIndexed() and isTokenized() to return true.
void setValue(Reader value)
Expert: change the value of this field.
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(String value)

Expert: change the value of this field.

String stringValue()
The value of the field as a String, or null.
TokenStream tokenStreamValue()
The TokesStream for this field to be used when indexing, or null.
[Expand]
Inherited Methods
From class org.apache.lucene.document.AbstractField
From class java.lang.Object
From interface org.apache.lucene.document.Fieldable

Public Constructors

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

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

public Field (String name, boolean internName, 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
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
IllegalArgumentException in any of the following situations:
  • the field is neither stored nor indexed
  • the field is not indexed but termVector is TermVector.YES

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 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

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 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

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 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

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 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

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

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

Public Methods

public Reader readerValue ()

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.

public 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()

public void setValue (Reader value)

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

public void setValue (byte[] value)

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

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

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

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.

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

public String stringValue ()

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.

public TokenStream tokenStreamValue ()

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.