Class JapaneseCompletionFilter
- java.lang.Object
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- org.apache.lucene.util.AttributeSource
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- org.apache.lucene.analysis.TokenStream
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- org.apache.lucene.analysis.TokenFilter
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- org.apache.lucene.analysis.ja.JapaneseCompletionFilter
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- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
,Unwrappable<TokenStream>
public final class JapaneseCompletionFilter extends TokenFilter
ATokenFilter
that adds Japanese romanized tokens to the term attribute. Also, this keeps original tokens (surface forms). Main usage of this filter is Query Auto-Completion.Supported romanization systems: (modified) Hepburn-shiki, Kunrei-shiki (Nihon-shiki) and Wāpuro shiki.
This does not strictly comply with the romanization systems listed above, but tries to cover possible keystroke supported by various Input Methods. e.g.: Circumflex / Macron representing Chōonpu (長音符) are not supported.
The romanization behaviour changes according to its
JapaneseCompletionFilter.Mode
. The default mode isJapaneseCompletionFilter.Mode.INDEX
.Note: This filter must be applied AFTER half-width and full-width normalization. Please ensure that a width normalizer such as
CJKWidthCharFilter
orCJKWidthFilter
is included in your analysis chain. IF THE WIDTH NORMALIZATION IS NOT PERFORMED, THIS DOES NOT WORK AS EXPECTED. See also:JapaneseCompletionAnalyzer
.
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Nested Class Summary
Nested Classes Modifier and Type Class Description private static class
JapaneseCompletionFilter.CompletionToken
private static class
JapaneseCompletionFilter.CompletionTokenGenerator
static class
JapaneseCompletionFilter.Mode
Completion mode-
Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.State
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Field Summary
Fields Modifier and Type Field Description static JapaneseCompletionFilter.Mode
DEFAULT_MODE
private boolean
inputStreamConsumed
private OffsetAttribute
offsetAtt
private PositionIncrementAttribute
posIncAtt
private ReadingAttribute
readingAttr
private CharTermAttribute
termAttr
private JapaneseCompletionFilter.CompletionTokenGenerator
tokenGenerator
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Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
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Fields inherited from class org.apache.lucene.analysis.TokenStream
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
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Constructor Summary
Constructors Constructor Description JapaneseCompletionFilter(TokenStream input)
Creates a newJapaneseCompletionFilter
with default configurationsJapaneseCompletionFilter(TokenStream input, JapaneseCompletionFilter.Mode mode)
Creates a newJapaneseCompletionFilter
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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.private void
mayIncrementToken()
void
reset()
This method is called by a consumer before it begins consumption usingTokenStream.incrementToken()
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Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end, unwrap
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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 Detail
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DEFAULT_MODE
public static final JapaneseCompletionFilter.Mode DEFAULT_MODE
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termAttr
private final CharTermAttribute termAttr
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readingAttr
private final ReadingAttribute readingAttr
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posIncAtt
private final PositionIncrementAttribute posIncAtt
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offsetAtt
private final OffsetAttribute offsetAtt
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tokenGenerator
private final JapaneseCompletionFilter.CompletionTokenGenerator tokenGenerator
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inputStreamConsumed
private boolean inputStreamConsumed
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Constructor Detail
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JapaneseCompletionFilter
public JapaneseCompletionFilter(TokenStream input)
Creates a newJapaneseCompletionFilter
with default configurations
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JapaneseCompletionFilter
public JapaneseCompletionFilter(TokenStream input, JapaneseCompletionFilter.Mode mode)
Creates a newJapaneseCompletionFilter
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Method Detail
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reset
public void reset() throws java.io.IOException
Description copied from class:TokenFilter
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).NOTE: The default implementation chains the call to the input TokenStream, so be sure to call
super.reset()
when overriding this method.- Overrides:
reset
in classTokenFilter
- Throws:
java.io.IOException
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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
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mayIncrementToken
private void mayIncrementToken() throws java.io.IOException
- Throws:
java.io.IOException
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