Package org.apache.lucene.analysis.de
Class GermanNormalizationFilter
java.lang.Object
org.apache.lucene.util.AttributeSource
org.apache.lucene.analysis.TokenStream
org.apache.lucene.analysis.TokenFilter
org.apache.lucene.analysis.de.GermanNormalizationFilter
- All Implemented Interfaces:
Closeable
,AutoCloseable
,Unwrappable<TokenStream>
Normalizes German characters according to the heuristics of the German2 snowball algorithm.
It allows for the fact that ä, ö and ü are sometimes written as ae, oe and ue.
- 'ß' is replaced by 'ss'
- 'ä', 'ö', 'ü' are replaced by 'a', 'o', 'u', respectively.
- 'ae' and 'oe' are replaced by 'a', and 'o', respectively.
- 'ue' is replaced by 'u', when not following a vowel or q.
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.State
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Field Summary
Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
Fields inherited from class org.apache.lucene.analysis.TokenStream
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
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Constructor Summary
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Method Summary
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end, reset, unwrap
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
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Constructor Details
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GermanNormalizationFilter
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Method Details
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incrementToken
- Specified by:
incrementToken
in classTokenStream
- Throws:
IOException
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