public final class CachingTokenFilter extends TokenFilter
CachingTokenFilter implements the optional method
TokenStream.reset(), which repositions the
stream to the first Token.
|Constructor and Description|
Create a new CachingTokenFilter around
|Modifier and Type||Method and Description|
This method is called by the consumer after the last token has been consumed, after
Rewinds the iterator to the beginning of the cached list.
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, restoreState, toString
public CachingTokenFilter(TokenStream input)
input, caching its token attributes, which can be replayed again after a call to
public final boolean incrementToken() throws IOException
IndexWriter) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriate
AttributeImpls 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
references to all
AttributeImpls 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
public final void end()
false(using the new
TokenStreamAPI). 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
The default implementation chains the call to the input TokenStream, so
be sure to call
super.end() first when overriding this method.
public void reset()
Note that this does not call reset() on the wrapped tokenstream ever, even the first time. You should reset() the inner tokenstream before wrapping it with CachingTokenFilter.
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