Class CapitalizationFilter
- All Implemented Interfaces:
Closeable
,AutoCloseable
,Unwrappable<TokenStream>
This filter is particularly useful to build nice looking facet parameters. This filter is not appropriate if you intend to use a prefix query.
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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
FieldsModifier and TypeFieldDescriptionstatic final int
static final int
private final boolean
private final CharArraySet
private final int
private final int
private final int
private final Collection<char[]>
private final boolean
private final CharTermAttribute
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
ConstructorsConstructorDescriptionCreates a CapitalizationFilter with the default parameters.CapitalizationFilter
(TokenStream in, boolean onlyFirstWord, CharArraySet keep, boolean forceFirstLetter, Collection<char[]> okPrefix, int minWordLength, int maxWordCount, int maxTokenLength) Creates a CapitalizationFilter with the specified parameters. -
Method Summary
Modifier and TypeMethodDescriptionboolean
Consumers (i.e.,IndexWriter
) use this method to advance the stream to the next token.private void
processWord
(char[] buffer, int offset, int length, int wordCount) 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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Field Details
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DEFAULT_MAX_WORD_COUNT
public static final int DEFAULT_MAX_WORD_COUNT- See Also:
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DEFAULT_MAX_TOKEN_LENGTH
public static final int DEFAULT_MAX_TOKEN_LENGTH- See Also:
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onlyFirstWord
private final boolean onlyFirstWord -
keep
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forceFirstLetter
private final boolean forceFirstLetter -
okPrefix
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minWordLength
private final int minWordLength -
maxWordCount
private final int maxWordCount -
maxTokenLength
private final int maxTokenLength -
termAtt
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Constructor Details
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CapitalizationFilter
Creates a CapitalizationFilter with the default parameters. -
CapitalizationFilter
public CapitalizationFilter(TokenStream in, boolean onlyFirstWord, CharArraySet keep, boolean forceFirstLetter, Collection<char[]> okPrefix, int minWordLength, int maxWordCount, int maxTokenLength) Creates a CapitalizationFilter with the specified parameters.- Parameters:
in
- input tokenstreamonlyFirstWord
- should each word be capitalized or all of the words?keep
- a keep word list. Each word that should be kept separated by whitespace.forceFirstLetter
- Force the first letter to be capitalized even if it is in the keep list.okPrefix
- do not change word capitalization if a word begins with something in this list.minWordLength
- how long the word needs to be to get capitalization applied. If the minWordLength is 3, "and" > "And" but "or" stays "or".maxWordCount
- if the token contains more then maxWordCount words, the capitalization is assumed to be correct.maxTokenLength
- ???
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Method Details
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incrementToken
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:
IOException
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processWord
private void processWord(char[] buffer, int offset, int length, int wordCount)
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