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java.lang.Object org.apache.lucene.util.AttributeSource org.apache.lucene.analysis.TokenStream org.apache.lucene.analysis.Tokenizer org.apache.lucene.analysis.CharTokenizer
public abstract class CharTokenizer
An abstract base class for simple, character-oriented tokenizers.
Nested Class Summary |
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Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource |
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AttributeSource.AttributeFactory, AttributeSource.State |
Field Summary |
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Fields inherited from class org.apache.lucene.analysis.Tokenizer |
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input |
Constructor Summary | |
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CharTokenizer(AttributeSource.AttributeFactory factory,
Reader input)
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CharTokenizer(AttributeSource source,
Reader input)
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CharTokenizer(Reader input)
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Method Summary | |
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void |
end()
This method is called by the consumer after the last token has been consumed, after TokenStream.incrementToken() returned false
(using the new TokenStream API). |
boolean |
incrementToken()
Consumers (i.e., IndexWriter ) use this method to advance the stream to
the next token. |
protected abstract boolean |
isTokenChar(char c)
Returns true iff a character should be included in a token. |
protected char |
normalize(char c)
Called on each token character to normalize it before it is added to the token. |
void |
reset(Reader input)
Expert: Reset the tokenizer to a new reader. |
Methods inherited from class org.apache.lucene.analysis.Tokenizer |
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close, correctOffset |
Methods inherited from class org.apache.lucene.analysis.TokenStream |
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reset |
Methods inherited from class org.apache.lucene.util.AttributeSource |
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addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, restoreState, toString |
Methods inherited from class java.lang.Object |
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clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
Constructor Detail |
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public CharTokenizer(Reader input)
public CharTokenizer(AttributeSource source, Reader input)
public CharTokenizer(AttributeSource.AttributeFactory factory, Reader input)
Method Detail |
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protected abstract boolean isTokenChar(char c)
protected char normalize(char c)
public final boolean incrementToken() throws IOException
TokenStream
IndexWriter
) use this method to advance the stream to
the next token. Implementing classes must implement this method and update
the appropriate AttributeImpl
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)
and AttributeSource.getAttribute(Class)
,
references to all AttributeImpl
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()
.
incrementToken
in class TokenStream
IOException
public final void end()
TokenStream
TokenStream.incrementToken()
returned false
(using the new TokenStream
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.
end
in class TokenStream
public void reset(Reader input) throws IOException
Tokenizer
reset
in class Tokenizer
IOException
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