org.apache.lucene.document

Class Field

Implemented Interfaces:
Serializable

public final class Field
extends Object
implements 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.

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.

Constructor Summary

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 string, boolean store, boolean index, boolean token)
Deprecated. use Field(String,String,Field.Store,Field.Index) instead
Field(String name, String string, boolean store, boolean index, boolean token, boolean storeTermVector)
Deprecated. use Field(String,String,Field.Store,Field.Index,Field.TermVector) instead
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, byte[] value, Field.Store store)
Create a stored field with binary value.

Method Summary

static Field
Keyword(String name, Date value)
Deprecated. use Field(name, value, Field.Store.YES, Field.Index.UN_TOKENIZED) instead
static Field
Keyword(String name, String value)
Deprecated. use Field(name, value, Field.Store.YES, Field.Index.UN_TOKENIZED) instead
static Field
Text(String name, Reader value)
Deprecated. use Field(name, value) instead
static Field
Text(String name, Reader value, boolean storeTermVector)
Deprecated. use Field(name, value, storeTermVector) instead
static Field
Text(String name, String value)
Deprecated. use Field(name, value, Field.Store.YES, Field.Index.TOKENIZED) instead
static Field
Text(String name, String value, boolean storeTermVector)
Deprecated. use Field(name, value, Field.Store.YES, Field.Index.TOKENIZED, storeTermVector) instead
static Field
UnIndexed(String name, String value)
Deprecated. use Field(name, value, Field.Store.YES, Field.Index.NO) instead
static Field
UnStored(String name, String value)
Deprecated. use Field(name, value, Field.Store.NO, Field.Index.TOKENIZED) instead
static Field
UnStored(String name, String value, boolean storeTermVector)
Deprecated. use Field(name, value, Field.Store.NO, Field.Index.TOKENIZED, storeTermVector) instead
byte[]
binaryValue()
The value of the field in Binary, or null.
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
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
isStored()
True iff the value of the field is to be stored in the index for return with search hits.
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.
String
name()
Returns the name of the field as an interned string.
Reader
readerValue()
The value of the field as a Reader, or null.
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.
String
stringValue()
The value of the field as a String, or null.
String
toString()
Prints a Field for human consumption.

Constructor Details

Field

public Field(String name,
             Reader reader)
Create a tokenized and indexed field that is not stored. Term vectors will not be stored.
Parameters:
name - The name of the field
reader - The reader with the content

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.
Parameters:
name - The name of the field
reader - The reader with the content
termVector - Whether term vector should be stored

Field

public Field(String name,
             String string,
             boolean store,
             boolean index,
             boolean token)

Deprecated. use Field(String,String,Field.Store,Field.Index) instead

Create a field by specifying all parameters except for storeTermVector, which is set to false.

Field

public Field(String name,
             String string,
             boolean store,
             boolean index,
             boolean token,
             boolean storeTermVector)

Deprecated. use Field(String,String,Field.Store,Field.Index,Field.TermVector) instead

Parameters:
name - The name of the field
string - The string to process
store - true if the field should store the string
index - true if the field should be indexed
token - true if the field should be tokenized
storeTermVector - true if we should store the Term Vector info

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

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

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)

Method Details

Keyword

public static final Field Keyword(String name,
                                  Date value)

Deprecated. use Field(name, value, Field.Store.YES, Field.Index.UN_TOKENIZED) instead

Constructs a Date-valued Field that is not tokenized and is indexed, and stored in the index, for return with hits.

Keyword

public static final Field Keyword(String name,
                                  String value)

Deprecated. use Field(name, value, Field.Store.YES, Field.Index.UN_TOKENIZED) instead

Constructs a String-valued Field that is not tokenized, but is indexed and stored. Useful for non-text fields, e.g. date or url.

Text

public static final Field Text(String name,
                               Reader value)

Deprecated. use Field(name, value) instead

Constructs a Reader-valued Field that is tokenized and indexed, but is not stored in the index verbatim. Useful for longer text fields, like "body". Term vector will not be stored for this field.

Text

public static final Field Text(String name,
                               Reader value,
                               boolean storeTermVector)

Deprecated. use Field(name, value, storeTermVector) instead

Constructs a Reader-valued Field that is tokenized and indexed, but is not stored in the index verbatim. Useful for longer text fields, like "body".

Text

public static final Field Text(String name,
                               String value)

Deprecated. use Field(name, value, Field.Store.YES, Field.Index.TOKENIZED) instead

Constructs a String-valued Field that is tokenized and indexed, and is stored in the index, for return with hits. Useful for short text fields, like "title" or "subject". Term vector will not be stored for this field.

Text

public static final Field Text(String name,
                               String value,
                               boolean storeTermVector)

Deprecated. use Field(name, value, Field.Store.YES, Field.Index.TOKENIZED, storeTermVector) instead

Constructs a String-valued Field that is tokenized and indexed, and is stored in the index, for return with hits. Useful for short text fields, like "title" or "subject".

UnIndexed

public static final Field UnIndexed(String name,
                                    String value)

Deprecated. use Field(name, value, Field.Store.YES, Field.Index.NO) instead

Constructs a String-valued Field that is not tokenized nor indexed, but is stored in the index, for return with hits.

UnStored

public static final Field UnStored(String name,
                                   String value)

Deprecated. use Field(name, value, Field.Store.NO, Field.Index.TOKENIZED) instead

Constructs a String-valued Field that is tokenized and indexed, but that is not stored in the index. Term vector will not be stored for this field.

UnStored

public static final Field UnStored(String name,
                                   String value,
                                   boolean storeTermVector)

Deprecated. use Field(name, value, Field.Store.NO, Field.Index.TOKENIZED, storeTermVector) instead

Constructs a String-valued Field that is tokenized and indexed, but that is not stored in the index.

binaryValue

public byte[] binaryValue()
The value of the field in Binary, or null. If null, the Reader or String value is used. Exactly one of stringValue(), readerValue() and binaryValue() must be set.

getBoost

public float getBoost()

getOmitNorms

public boolean getOmitNorms()
True if norms are omitted for this indexed field

isBinary

public final boolean isBinary()
True iff the value of the filed is stored as binary

isCompressed

public final boolean isCompressed()
True if the value of the field is stored and compressed within the index

isIndexed

public final boolean isIndexed()
True iff the value of the field is to be indexed, so that it may be searched on.

isStoreOffsetWithTermVector

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

isStorePositionWithTermVector

public boolean isStorePositionWithTermVector()
True iff terms are stored as term vector together with their token positions.

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.

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.

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.

name

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

readerValue

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 binaryValue() must be set.

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.


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.

stringValue

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 binaryValue() must be set.

toString

public final String toString()
Prints a Field for human consumption.

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