org.apache.lucene.codecs

Class StoredFieldsWriter.MergeVisitor

java.lang.Object

org.apache.lucene.index.StoredFieldVisitor

org.apache.lucene.codecs.StoredFieldsWriter.MergeVisitor

All Implemented Interfaces:

IndexableField

Enclosing class:

StoredFieldsWriter

protected class StoredFieldsWriter.MergeVisitor
extends StoredFieldVisitor
implements IndexableField

A visitor that adds every field it sees.

Use like this:

 MergeVisitor visitor = new MergeVisitor(mergeState, readerIndex);
 for (...) {
   startDocument();
   storedFieldsReader.visitDocument(docID, visitor);
   finishDocument();
 }
 

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.index.StoredFieldVisitor

StoredFieldVisitor.Status

Constructor Summary

Constructors

Constructor and Description
StoredFieldsWriter.MergeVisitor(MergeState mergeState, int readerIndex) Create new merge visitor.

Method Summary

Methods

Modifier and Type	Method and Description
void	binaryField(FieldInfo fieldInfo, byte[] value) Process a binary field.
BytesRef	binaryValue() Non-null if this field has a binary value
float	boost() Returns the field's index-time boost.
void	doubleField(FieldInfo fieldInfo, double value) Process a double numeric field.
IndexableFieldType	fieldType() IndexableFieldType describing the properties of this field.
void	floatField(FieldInfo fieldInfo, float value) Process a float numeric field.
void	intField(FieldInfo fieldInfo, int value) Process a int numeric field.
void	longField(FieldInfo fieldInfo, long value) Process a long numeric field.
String	name() Field name
StoredFieldVisitor.Status	needsField(FieldInfo fieldInfo) Hook before processing a field.
Number	numericValue() Non-null if this field has a numeric value
Reader	readerValue() Non-null if this field has a Reader value
void	stringField(FieldInfo fieldInfo, byte[] value) Process a string field; the provided byte[] value is a UTF-8 encoded string value.
String	stringValue() Non-null if this field has a string value
TokenStream	tokenStream(Analyzer analyzer, TokenStream reuse) Creates the TokenStream used for indexing this field.

Methods inherited from class java.lang.Object

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

Constructor Detail

StoredFieldsWriter.MergeVisitor

public StoredFieldsWriter.MergeVisitor(MergeState mergeState,
                               int readerIndex)

Create new merge visitor.

Method Detail

binaryField

public void binaryField(FieldInfo fieldInfo,
               byte[] value)
                 throws IOException

Description copied from class: StoredFieldVisitor

Process a binary field.

Overrides:

binaryField in class StoredFieldVisitor

value - newly allocated byte array with the binary contents.

Throws:

IOException

stringField

public void stringField(FieldInfo fieldInfo,
               byte[] value)
                 throws IOException

Description copied from class: StoredFieldVisitor

Process a string field; the provided byte[] value is a UTF-8 encoded string value.

Overrides:

stringField in class StoredFieldVisitor

Throws:

IOException

intField

public void intField(FieldInfo fieldInfo,
            int value)
              throws IOException

Description copied from class: StoredFieldVisitor

Process a int numeric field.

Overrides:

intField in class StoredFieldVisitor

Throws:

IOException

longField

public void longField(FieldInfo fieldInfo,
             long value)
               throws IOException

Description copied from class: StoredFieldVisitor

Process a long numeric field.

Overrides:

longField in class StoredFieldVisitor

Throws:

IOException

floatField

public void floatField(FieldInfo fieldInfo,
              float value)
                throws IOException

Description copied from class: StoredFieldVisitor

Process a float numeric field.

Overrides:

floatField in class StoredFieldVisitor

Throws:

IOException

doubleField

public void doubleField(FieldInfo fieldInfo,
               double value)
                 throws IOException

Description copied from class: StoredFieldVisitor

Process a double numeric field.

Overrides:

doubleField in class StoredFieldVisitor

Throws:

IOException

needsField

public StoredFieldVisitor.Status needsField(FieldInfo fieldInfo)
                                     throws IOException

Description copied from class: StoredFieldVisitor

Hook before processing a field. Before a field is processed, this method is invoked so that subclasses can return a StoredFieldVisitor.Status representing whether they need that particular field or not, or to stop processing entirely.

Specified by:

needsField in class StoredFieldVisitor

Throws:

IOException

name

public String name()

Description copied from interface: IndexableField

Field name

Specified by:

name in interface IndexableField

fieldType

public IndexableFieldType fieldType()

Description copied from interface: IndexableField

IndexableFieldType describing the properties of this field.

Specified by:

fieldType 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

stringValue

public String stringValue()

Description copied from interface: IndexableField

Non-null if this field has a string value

Specified by:

stringValue 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

readerValue

public Reader readerValue()

Description copied from interface: IndexableField

Non-null if this field has a Reader value

Specified by:

readerValue in interface IndexableField

boost

public float boost()

Description copied from interface: IndexableField

Returns the field's index-time boost.

Only fields can have an index-time boost, if you want to simulate a "document boost", then you must pre-multiply it across all the relevant fields yourself.

The boost is used to compute the norm factor for the field. By default, in the Similarity.computeNorm(FieldInvertState) method, the boost value is multiplied by the length normalization factor and then rounded by DefaultSimilarity.encodeNormValue(float) before it is stored in the index. One should attempt to ensure that this product does not overflow the range of that encoding.

It is illegal to return a boost other than 1.0f for a field that is not indexed (IndexableFieldType.indexOptions() is IndexOptions.NONE) or omits normalization values (IndexableFieldType.omitNorms() returns true).

Specified by:

boost in interface IndexableField

See Also:

Similarity.computeNorm(FieldInvertState), DefaultSimilarity.encodeNormValue(float)

tokenStream

public TokenStream tokenStream(Analyzer analyzer,
                      TokenStream reuse)
                        throws IOException

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 its 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

Throws:

IOException - Can be thrown while creating the TokenStream