Field (Lucene 7.2.0 API)

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

All Implemented Interfaces:

IndexableField

Direct Known Subclasses:

BinaryDocValuesField, BinaryPoint, DoublePoint, DoubleRange, FloatPoint, FloatRange, IntPoint, IntRange, LongPoint, LongRange, NumericDocValuesField, SortedDocValuesField, SortedNumericDocValuesField, SortedSetDocValuesField, StoredField, StringField, TextField
```
public class Field
extends Object
implements IndexableField
```
Expert: directly create a field for a document. Most users should use one of the sugar subclasses:
- TextField: Reader or String indexed for full-text search
- StringField: String indexed verbatim as a single token
- IntPoint: int indexed for exact/range queries.
- LongPoint: long indexed for exact/range queries.
- FloatPoint: float indexed for exact/range queries.
- DoublePoint: double indexed for exact/range queries.
- SortedDocValuesField: byte[] indexed column-wise for sorting/faceting
- SortedSetDocValuesField: SortedSet<byte[]> indexed column-wise for sorting/faceting
- NumericDocValuesField: long indexed column-wise for sorting/faceting
- SortedNumericDocValuesField: SortedSet<long> indexed column-wise for sorting/faceting
- StoredField: Stored-only value for retrieving in summary results
A field is a section of a Document. Each field has three parts: name, type and value. Values may be text (String, Reader or pre-analyzed TokenStream), binary (byte[]), or numeric (a Number). Fields are optionally stored in the index, so that they may be returned with hits on the document.
NOTE: the field type is an IndexableFieldType. Making changes to the state of the IndexableFieldType will impact any Field it is used in. It is strongly recommended that no changes be made after Field instantiation.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class Field.Store
Specifies whether and how a field should be stored.

Nested Classes
Modifier and Type	Class and Description
`static class`	`Field.Store` Specifies whether and how a field should be stored.

Field Summary

Fields
Modifier and Type	Field and Description
`protected Object`	`fieldsData` Field's value
`protected String`	`name` Field's name
`protected TokenStream`	`tokenStream` Pre-analyzed tokenStream for indexed fields; this is separate from fieldsData because you are allowed to have both; eg maybe field has a String value but you customize how it's tokenized
`protected IndexableFieldType`	`type` Field's type

Constructor Summary

Constructors
Modifier	Constructor and Description
	`Field(String name, byte[] value, IndexableFieldType type)` Create field with binary value.
	`Field(String name, byte[] value, int offset, int length, IndexableFieldType type)` Create field with binary value.
	`Field(String name, BytesRef bytes, IndexableFieldType type)` Create field with binary value.
`protected`	`Field(String name, IndexableFieldType type)` Expert: creates a field with no initial value.
	`Field(String name, Reader reader, IndexableFieldType type)` Create field with Reader value.
	`Field(String name, String value, IndexableFieldType type)` Create field with String value.
	`Field(String name, TokenStream tokenStream, IndexableFieldType type)` Create field with TokenStream value.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`BytesRef`	`binaryValue()` Non-null if this field has a binary value
`IndexableFieldType`	`fieldType()` Returns the `FieldType` for this field.
`String`	`name()` Field name
`Number`	`numericValue()` Non-null if this field has a numeric value
`Reader`	`readerValue()` The value of the field as a Reader, or null.
`void`	`setBytesValue(byte[] value)` Expert: change the value of this field.
`void`	`setBytesValue(BytesRef value)` Expert: change the value of this field.
`void`	`setByteValue(byte value)` Expert: change the value of this field.
`void`	`setDoubleValue(double value)` Expert: change the value of this field.
`void`	`setFloatValue(float value)` Expert: change the value of this field.
`void`	`setIntValue(int value)` Expert: change the value of this field.
`void`	`setLongValue(long value)` Expert: change the value of this field.
`void`	`setReaderValue(Reader value)` Expert: change the value of this field.
`void`	`setShortValue(short value)` Expert: change the value of this field.
`void`	`setStringValue(String value)` Expert: change the value of this field.
`void`	`setTokenStream(TokenStream tokenStream)` Expert: sets the token stream to be used for indexing and causes isIndexed() and isTokenized() to return true.
`String`	`stringValue()` The value of the field as a String, or null.
`TokenStream`	`tokenStream(Analyzer analyzer, TokenStream reuse)` Creates the TokenStream used for indexing this field.
`TokenStream`	`tokenStreamValue()` The TokenStream for this field to be used when indexing, or null.
`String`	`toString()` Prints a Field for human consumption.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - type
```
protected final IndexableFieldType type
```
    Field's type
  - name
```
protected final String name
```
    Field's name
  - fieldsData
```
protected Object fieldsData
```
    Field's value
  - tokenStream
```
protected TokenStream tokenStream
```
    Pre-analyzed tokenStream for indexed fields; this is separate from fieldsData because you are allowed to have both; eg maybe field has a String value but you customize how it's tokenized
- Constructor Detail
  - Field
```
protected Field(String name,
                IndexableFieldType type)
```
    Expert: creates a field with no initial value. Intended only for custom Field subclasses.
    
    Parameters:
    
    name - field name
    
    type - field type
    
    Throws:
    
    IllegalArgumentException - if either the name or type is null.
  - Field
```
public Field(String name,
             Reader reader,
             IndexableFieldType type)
```
    Create field with Reader value.
    
    Parameters:
    
    name - field name
    
    reader - reader value
    
    type - field type
    
    Throws:
    
    IllegalArgumentException - if either the name or type is null, or if the field's type is stored(), or if tokenized() is false.
    
    NullPointerException - if the reader is null
  - Field
```
public Field(String name,
             TokenStream tokenStream,
             IndexableFieldType type)
```
    Create field with TokenStream value.
    
    Parameters:
    
    name - field name
    
    tokenStream - TokenStream value
    
    type - field type
    
    Throws:
    
    IllegalArgumentException - if either the name or type is null, or if the field's type is stored(), or if tokenized() is false, or if indexed() is false.
    
    NullPointerException - if the tokenStream is null
  - Field
```
public Field(String name,
             byte[] value,
             IndexableFieldType type)
```
    Create field with binary value.
    NOTE: the provided byte[] is not copied so be sure not to change it until you're done with this field.
    
    Parameters:
    
    name - field name
    
    value - byte array pointing to binary content (not copied)
    
    type - field type
    
    Throws:
    
    IllegalArgumentException - if the field name is null, or the field's type is indexed()
    
    NullPointerException - if the type is null
  - Field
```
public Field(String name,
             byte[] value,
             int offset,
             int length,
             IndexableFieldType type)
```
    Create field with binary value.
    NOTE: the provided byte[] is not copied so be sure not to change it until you're done with this field.
    
    Parameters:
    
    name - field name
    
    value - byte array pointing to binary content (not copied)
    
    offset - starting position of the byte array
    
    length - valid length of the byte array
    
    type - field type
    
    Throws:
    
    IllegalArgumentException - if the field name is null, or the field's type is indexed()
    
    NullPointerException - if the type is null
  - Field
```
public Field(String name,
             BytesRef bytes,
             IndexableFieldType type)
```
    Create field with binary value.
    NOTE: the provided BytesRef is not copied so be sure not to change it until you're done with this field.
    
    Parameters:
    
    name - field name
    
    bytes - BytesRef pointing to binary content (not copied)
    
    type - field type
    
    Throws:
    
    IllegalArgumentException - if the field name is null, or the field's type is indexed()
    
    NullPointerException - if the type is null
  - Field
```
public Field(String name,
             String value,
             IndexableFieldType type)
```
    Create field with String value.
    
    Parameters:
    
    name - field name
    
    value - string value
    
    type - field type
    
    Throws:
    
    IllegalArgumentException - if either the name or value is null, or if the field's type is neither indexed() nor stored(), or if indexed() is false but storeTermVectors() is true.
    
    NullPointerException - if the type is null
- Method Detail
  - 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.
    
    Specified by:
    
    stringValue in interface IndexableField
  - 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.
    
    Specified by:
    
    readerValue in interface IndexableField
  - tokenStreamValue
```
public TokenStream tokenStreamValue()
```
    The TokenStream 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.
  - setStringValue
```
public void setStringValue(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.
  - setReaderValue
```
public void setReaderValue(Reader value)
```
    Expert: change the value of this field. See setStringValue(String).
  - setBytesValue
```
public void setBytesValue(byte[] value)
```
    Expert: change the value of this field. See setStringValue(String).
  - setBytesValue
```
public void setBytesValue(BytesRef value)
```
    Expert: change the value of this field. See setStringValue(String).
    NOTE: the provided BytesRef is not copied so be sure not to change it until you're done with this field.
  - setByteValue
```
public void setByteValue(byte value)
```
    Expert: change the value of this field. See setStringValue(String).
  - setShortValue
```
public void setShortValue(short value)
```
    Expert: change the value of this field. See setStringValue(String).
  - setIntValue
```
public void setIntValue(int value)
```
    Expert: change the value of this field. See setStringValue(String).
  - setLongValue
```
public void setLongValue(long value)
```
    Expert: change the value of this field. See setStringValue(String).
  - setFloatValue
```
public void setFloatValue(float value)
```
    Expert: change the value of this field. See setStringValue(String).
  - setDoubleValue
```
public void setDoubleValue(double value)
```
    Expert: change the value of this field. See setStringValue(String).
  - setTokenStream
```
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 binaryValue()
  - name
```
public String name()
```
    Description copied from interface: IndexableField
    
    Field name
    
    Specified by:
    
    name in interface IndexableField
  - numericValue
```
public Number numericValue()
```
    Description copied from interface: IndexableField
    
    Non-null if this field has a numeric value
    
    Specified by:
    
    numericValue in interface IndexableField
  - binaryValue
```
public BytesRef binaryValue()
```
    Description copied from interface: IndexableField
    
    Non-null if this field has a binary value
    
    Specified by:
    
    binaryValue in interface IndexableField
  - toString
```
public String toString()
```
    Prints a Field for human consumption.
    
    Overrides:
    
    toString in class Object
  - fieldType
```
public IndexableFieldType fieldType()
```
    Returns the FieldType for this field.
    
    Specified by:
    
    fieldType in interface IndexableField
  - tokenStream
```
public TokenStream tokenStream(Analyzer analyzer,
                               TokenStream reuse)
```
    Description copied from interface: IndexableField
    
    Creates the TokenStream used for indexing this field. If appropriate, implementations should use the given Analyzer to create the TokenStreams.
    
    Specified by:
    
    tokenStream in interface IndexableField
    
    Parameters:
    
    analyzer - Analyzer that should be used to create the TokenStreams from
    
    reuse - TokenStream for a previous instance of this field name. This allows custom field types (like StringField and NumericField) that do not use the analyzer to still have good performance. Note: the passed-in type may be inappropriate, for example if you mix up different types of Fields for the same field name. So it's the responsibility of the implementation to check.
    
    Returns:
    
    TokenStream value for indexing the document. Should always return a non-null value if the field is to be indexed

Class Field

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

type

name

fieldsData

tokenStream

Constructor Detail

Field

Field

Field

Field

Field

Field

Field

Method Detail

stringValue

readerValue

tokenStreamValue

setStringValue

setReaderValue

setBytesValue

setBytesValue

setByteValue

setShortValue

setIntValue

setLongValue

setFloatValue

setDoubleValue

setTokenStream

name

numericValue

binaryValue

toString

fieldType

tokenStream