Class ScandinavianNormalizationFilter
- java.lang.Object
-
- org.apache.lucene.util.AttributeSource
-
- org.apache.lucene.analysis.TokenStream
-
- org.apache.lucene.analysis.TokenFilter
-
- org.apache.lucene.analysis.miscellaneous.ScandinavianNormalizationFilter
-
- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
public final class ScandinavianNormalizationFilter extends TokenFilter
This filter normalize use of the interchangeable Scandinavian characters æÆäÄöÖøØ and folded variants (aa, ao, ae, oe and oo) by transforming them to åÅæÆøØ.It's a semantically less destructive solution than
ScandinavianFoldingFilter
, most useful when a person with a Norwegian or Danish keyboard queries a Swedish index and vice versa. This filter does not the common Swedish folds of å and ä to a nor ö to o.blåbærsyltetøj == blåbärsyltetöj == blaabaarsyltetoej but not blabarsyltetoj räksmörgås == ræksmørgås == ræksmörgaos == raeksmoergaas but not raksmorgas
- See Also:
ScandinavianFoldingFilter
-
-
Nested Class Summary
-
Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.State
-
-
Field Summary
Fields Modifier and Type Field Description private static char
aa
private static char
AA
private static char
ae
private static char
AE
private static char
ae_se
private static char
AE_se
private CharTermAttribute
charTermAttribute
private static char
oe
private static char
OE
private static char
oe_se
private static char
OE_se
-
Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
-
Fields inherited from class org.apache.lucene.analysis.TokenStream
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
-
-
Constructor Summary
Constructors Constructor Description ScandinavianNormalizationFilter(TokenStream input)
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
incrementToken()
Consumers (i.e.,IndexWriter
) use this method to advance the stream to the next token.-
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end, reset
-
Methods inherited from class org.apache.lucene.util.AttributeSource
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
-
-
-
-
Field Detail
-
charTermAttribute
private final CharTermAttribute charTermAttribute
-
AA
private static final char AA
- See Also:
- Constant Field Values
-
aa
private static final char aa
- See Also:
- Constant Field Values
-
AE
private static final char AE
- See Also:
- Constant Field Values
-
ae
private static final char ae
- See Also:
- Constant Field Values
-
AE_se
private static final char AE_se
- See Also:
- Constant Field Values
-
ae_se
private static final char ae_se
- See Also:
- Constant Field Values
-
OE
private static final char OE
- See Also:
- Constant Field Values
-
oe
private static final char oe
- See Also:
- Constant Field Values
-
OE_se
private static final char OE_se
- See Also:
- Constant Field Values
-
oe_se
private static final char oe_se
- See Also:
- Constant Field Values
-
-
Constructor Detail
-
ScandinavianNormalizationFilter
public ScandinavianNormalizationFilter(TokenStream input)
-
-
Method Detail
-
incrementToken
public boolean incrementToken() throws java.io.IOException
Description copied from class:TokenStream
Consumers (i.e.,IndexWriter
) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriateAttributeImpl
s with the attributes of the next token.The producer must make no assumptions about the attributes after the method has been returned: the caller may arbitrarily change it. If the producer needs to preserve the state for subsequent calls, it can use
AttributeSource.captureState()
to create a copy of the current attribute state.This method is called for every token of a document, so an efficient implementation is crucial for good performance. To avoid calls to
AttributeSource.addAttribute(Class)
andAttributeSource.getAttribute(Class)
, references to allAttributeImpl
s that this stream uses should be retrieved during instantiation.To ensure that filters and consumers know which attributes are available, the attributes must be added during instantiation. Filters and consumers are not required to check for availability of attributes in
TokenStream.incrementToken()
.- Specified by:
incrementToken
in classTokenStream
- Returns:
- false for end of stream; true otherwise
- Throws:
java.io.IOException
-
-