Class TrimFilter
- 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.miscellaneous.TrimFilter
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- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
public final class TrimFilter extends TokenFilter
Trims leading and trailing whitespace from Tokens in the stream.As of Lucene 4.4, this filter does not support updateOffsets=true anymore as it can lead to broken token streams.
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.AttributeFactory, AttributeSource.State
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Constructor Summary
Constructors Constructor Description TrimFilter(Version version, TokenStream in)
Create a newTrimFilter
on top ofin
.TrimFilter(Version version, TokenStream in, boolean updateOffsets)
Deprecated.Offset updates are not supported anymore as of Lucene 4.4.
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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.-
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end, reset
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Methods inherited from class org.apache.lucene.util.AttributeSource
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, restoreState, toString
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Constructor Detail
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TrimFilter
@Deprecated public TrimFilter(Version version, TokenStream in, boolean updateOffsets)
Deprecated.Offset updates are not supported anymore as of Lucene 4.4.Create a newTrimFilter
.- Parameters:
version
- the Lucene match versionin
- the stream to consumeupdateOffsets
- whether to update offsets
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TrimFilter
public TrimFilter(Version version, TokenStream in)
Create a newTrimFilter
on top ofin
.
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Method Detail
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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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