Class SimplePatternTokenizer
- All Implemented Interfaces:
Closeable
,AutoCloseable
RegExp
or (expert usage) a pre-built determinized Automaton
, to locate tokens. The regexp syntax is more limited than PatternTokenizer
,
but the tokenization is quite a bit faster. The provided regex should match valid token
characters (not token separator characters, like String.split
). The matching is greedy:
the longest match at a given start point will be the next token. Empty string tokens are never
produced.-
Nested Class Summary
Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.State
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate final char[]
private int
private int
private int
private final OffsetAttribute
private char[]
private int
private int
private final CharacterRunAutomaton
private final CharTermAttribute
private int
Fields inherited from class org.apache.lucene.analysis.TokenStream
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
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Constructor Summary
ConstructorsConstructorDescriptionSimplePatternTokenizer
(String regexp) SeeRegExp
for the accepted syntax.SimplePatternTokenizer
(AttributeFactory factory, String regexp, int determinizeWorkLimit) SeeRegExp
for the accepted syntax.SimplePatternTokenizer
(AttributeFactory factory, Automaton dfa) Runs a pre-built automaton.Runs a pre-built automaton. -
Method Summary
Modifier and TypeMethodDescriptionprivate void
appendToToken
(char ch) void
end()
This method is called by the consumer after the last token has been consumed, afterTokenStream.incrementToken()
returnedfalse
(using the newTokenStream
API).boolean
Consumers (i.e.,IndexWriter
) use this method to advance the stream to the next token.private int
private int
private void
pushBack
(int count) Pushes back the lastcount
characters in current token's buffer.void
reset()
This method is called by a consumer before it begins consumption usingTokenStream.incrementToken()
.Methods inherited from class org.apache.lucene.analysis.Tokenizer
close, correctOffset, setReader, setReaderTestPoint
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
-
termAtt
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offsetAtt
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runDFA
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pendingChars
private char[] pendingChars -
pendingLimit
private int pendingLimit -
pendingUpto
private int pendingUpto -
offset
private int offset -
tokenUpto
private int tokenUpto -
buffer
private final char[] buffer -
bufferLimit
private int bufferLimit -
bufferNextRead
private int bufferNextRead
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Constructor Details
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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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end
Description copied from class:TokenStream
This method is called by the consumer after the last token has been consumed, afterTokenStream.incrementToken()
returnedfalse
(using the newTokenStream
API). Streams implementing the old API should upgrade to use this feature.This method can be used to perform any end-of-stream operations, such as setting the final offset of a stream. The final offset of a stream might differ from the offset of the last token eg in case one or more whitespaces followed after the last token, but a WhitespaceTokenizer was used.
Additionally any skipped positions (such as those removed by a stopfilter) can be applied to the position increment, or any adjustment of other attributes where the end-of-stream value may be important.
If you override this method, always call
super.end()
.- Overrides:
end
in classTokenStream
- Throws:
IOException
- If an I/O error occurs
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reset
Description copied from class:TokenStream
This method is called by a consumer before it begins consumption usingTokenStream.incrementToken()
.Resets this stream to a clean state. Stateful implementations must implement this method so that they can be reused, just as if they had been created fresh.
If you override this method, always call
super.reset()
, otherwise some internal state will not be correctly reset (e.g.,Tokenizer
will throwIllegalStateException
on further usage).- Overrides:
reset
in classTokenizer
- Throws:
IOException
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pushBack
private void pushBack(int count) Pushes back the lastcount
characters in current token's buffer. -
appendToToken
private void appendToToken(char ch) -
nextCodeUnit
- Throws:
IOException
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nextCodePoint
- Throws:
IOException
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