public abstract class TokenFilter extends TokenStream
This is an abstract class; subclasses must override TokenStream.incrementToken()
.
TokenStream
AttributeSource.State
Modifier and Type | Field and Description |
---|---|
protected TokenStream |
input
The source of tokens for this filter.
|
DEFAULT_TOKEN_ATTRIBUTE_FACTORY
Modifier | Constructor and Description |
---|---|
protected |
TokenFilter(TokenStream input)
Construct a token stream filtering the given input.
|
Modifier and Type | Method and Description |
---|---|
void |
close()
Releases resources associated with this stream.
|
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). |
void |
reset()
This method is called by a consumer before it begins consumption using
TokenStream.incrementToken() . |
incrementToken
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString
protected final TokenStream input
protected TokenFilter(TokenStream input)
public void end() throws IOException
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.
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()
.
NOTE:
The default implementation chains the call to the input TokenStream, so
be sure to call super.end()
first when overriding this method.
end
in class TokenStream
IOException
- If an I/O error occurspublic void close() throws IOException
If you override this method, always call super.close()
, otherwise
some internal state will not be correctly reset (e.g., Tokenizer
will
throw IllegalStateException
on reuse).
NOTE:
The default implementation chains the call to the input TokenStream, so
be sure to call super.close()
when overriding this method.
close
in interface Closeable
close
in interface AutoCloseable
close
in class TokenStream
IOException
public void reset() throws IOException
TokenStream.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
throw IllegalStateException
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.
reset
in class TokenStream
IOException
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