- java.lang.Object
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- org.apache.lucene.index.TermsEnum
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- org.apache.lucene.index.FilteredTermsEnum
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- All Implemented Interfaces:
BytesRefIterator
- Direct Known Subclasses:
AutomatonTermsEnum
,DocValuesConsumer.BitsFilteredTermsEnum
,SeekingTermSetTermsEnum
,SingleTermsEnum
,TermInSetQuery.SetEnum
public abstract class FilteredTermsEnum extends TermsEnum
Abstract class for enumerating a subset of all terms.Term enumerations are always ordered by
BytesRef.compareTo(org.apache.lucene.util.BytesRef)
. Each term in the enumeration is greater than all that precede it.Please note: Consumers of this enum cannot call
seek()
, it is forward only; it throwsUnsupportedOperationException
when a seeking method is called.
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Nested Class Summary
Nested Classes Modifier and Type Class Description protected static class
FilteredTermsEnum.AcceptStatus
Return value, if term should be accepted or the iteration shouldEND
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Nested classes/interfaces inherited from class org.apache.lucene.index.TermsEnum
TermsEnum.SeekStatus
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Field Summary
Fields Modifier and Type Field Description protected BytesRef
actualTerm
Which term the enum is currently positioned to.private boolean
doSeek
private BytesRef
initialSeekTerm
protected TermsEnum
tenum
The delegateTermsEnum
.
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Constructor Summary
Constructors Modifier Constructor Description protected
FilteredTermsEnum(TermsEnum tenum)
Creates a filteredTermsEnum
on a terms enum.protected
FilteredTermsEnum(TermsEnum tenum, boolean startWithSeek)
Creates a filteredTermsEnum
on a terms enum.
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected abstract FilteredTermsEnum.AcceptStatus
accept(BytesRef term)
Return if term is accepted, not accepted or the iteration should ended (and possibly seek).AttributeSource
attributes()
Returns the related attributes, the returnedAttributeSource
is shared with the delegateTermsEnum
.int
docFreq()
Returns the number of documents containing the current term.ImpactsEnum
impacts(int flags)
Return aImpactsEnum
.BytesRef
next()
Increments the iteration to the nextBytesRef
in the iterator.protected BytesRef
nextSeekTerm(BytesRef currentTerm)
On the first call tonext()
or ifaccept(org.apache.lucene.util.BytesRef)
returnsFilteredTermsEnum.AcceptStatus.YES_AND_SEEK
orFilteredTermsEnum.AcceptStatus.NO_AND_SEEK
, this method will be called to eventually seek the underlying TermsEnum to a new position.long
ord()
Returns ordinal position for current term.PostingsEnum
postings(PostingsEnum reuse, int flags)
GetPostingsEnum
for the current term, with control over whether freqs, positions, offsets or payloads are required.TermsEnum.SeekStatus
seekCeil(BytesRef term)
This enum does not support seeking!void
seekExact(long ord)
This enum does not support seeking!boolean
seekExact(BytesRef term)
This enum does not support seeking!void
seekExact(BytesRef term, TermState state)
This enum does not support seeking!protected void
setInitialSeekTerm(BytesRef term)
Use this method to set the initialBytesRef
to seek before iterating.BytesRef
term()
Returns current term.TermState
termState()
Returns the filtered enums term statelong
totalTermFreq()
Returns the total number of occurrences of this term across all documents (the sum of the freq() for each doc that has this term).
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Method Detail
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accept
protected abstract FilteredTermsEnum.AcceptStatus accept(BytesRef term) throws java.io.IOException
Return if term is accepted, not accepted or the iteration should ended (and possibly seek).- Throws:
java.io.IOException
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setInitialSeekTerm
protected final void setInitialSeekTerm(BytesRef term)
Use this method to set the initialBytesRef
to seek before iterating. This is a convenience method for subclasses that do not overridenextSeekTerm(org.apache.lucene.util.BytesRef)
. If the initial seek term isnull
(default), the enum is empty.You can only use this method, if you keep the default implementation of
nextSeekTerm(org.apache.lucene.util.BytesRef)
.
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nextSeekTerm
protected BytesRef nextSeekTerm(BytesRef currentTerm) throws java.io.IOException
On the first call tonext()
or ifaccept(org.apache.lucene.util.BytesRef)
returnsFilteredTermsEnum.AcceptStatus.YES_AND_SEEK
orFilteredTermsEnum.AcceptStatus.NO_AND_SEEK
, this method will be called to eventually seek the underlying TermsEnum to a new position. On the first call,currentTerm
will benull
, later calls will provide the term the underlying enum is positioned at. This method returns per default only one time the initial seek term and thennull
, so no repositioning is ever done.Override this method, if you want a more sophisticated TermsEnum, that repositions the iterator during enumeration. If this method always returns
null
the enum is empty.Please note: This method should always provide a greater term than the last enumerated term, else the behaviour of this enum violates the contract for TermsEnums.
- Throws:
java.io.IOException
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attributes
public AttributeSource attributes()
Returns the related attributes, the returnedAttributeSource
is shared with the delegateTermsEnum
.- Specified by:
attributes
in classTermsEnum
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term
public BytesRef term() throws java.io.IOException
Description copied from class:TermsEnum
Returns current term. Do not call this when the enum is unpositioned.
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docFreq
public int docFreq() throws java.io.IOException
Description copied from class:TermsEnum
Returns the number of documents containing the current term. Do not call this when the enum is unpositioned.TermsEnum.SeekStatus.END
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totalTermFreq
public long totalTermFreq() throws java.io.IOException
Description copied from class:TermsEnum
Returns the total number of occurrences of this term across all documents (the sum of the freq() for each doc that has this term). Note that, like other term measures, this measure does not take deleted documents into account.- Specified by:
totalTermFreq
in classTermsEnum
- Throws:
java.io.IOException
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seekExact
public boolean seekExact(BytesRef term) throws java.io.IOException
This enum does not support seeking!
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seekCeil
public TermsEnum.SeekStatus seekCeil(BytesRef term) throws java.io.IOException
This enum does not support seeking!
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seekExact
public void seekExact(long ord) throws java.io.IOException
This enum does not support seeking!
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ord
public long ord() throws java.io.IOException
Description copied from class:TermsEnum
Returns ordinal position for current term. This is an optional method (the codec may throwUnsupportedOperationException
). Do not call this when the enum is unpositioned.
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postings
public PostingsEnum postings(PostingsEnum reuse, int flags) throws java.io.IOException
Description copied from class:TermsEnum
GetPostingsEnum
for the current term, with control over whether freqs, positions, offsets or payloads are required. Do not call this when the enum is unpositioned. This method will not return null.NOTE: the returned iterator may return deleted documents, so deleted documents have to be checked on top of the
PostingsEnum
.- Specified by:
postings
in classTermsEnum
- Parameters:
reuse
- pass a prior PostingsEnum for possible reuseflags
- specifies which optional per-document values you require; seePostingsEnum.FREQS
- Throws:
java.io.IOException
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impacts
public ImpactsEnum impacts(int flags) throws java.io.IOException
Description copied from class:TermsEnum
Return aImpactsEnum
.- Specified by:
impacts
in classTermsEnum
- Throws:
java.io.IOException
- See Also:
TermsEnum.postings(PostingsEnum, int)
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seekExact
public void seekExact(BytesRef term, TermState state) throws java.io.IOException
This enum does not support seeking!
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termState
public TermState termState() throws java.io.IOException
Returns the filtered enums term state- Specified by:
termState
in classTermsEnum
- Throws:
java.io.IOException
- See Also:
TermState
,TermsEnum.seekExact(BytesRef, TermState)
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next
public BytesRef next() throws java.io.IOException
Description copied from interface:BytesRefIterator
Increments the iteration to the nextBytesRef
in the iterator. Returns the resultingBytesRef
ornull
if the end of the iterator is reached. The returned BytesRef may be re-used across calls to next. After this method returns null, do not call it again: the results are undefined.- Returns:
- the next
BytesRef
in the iterator ornull
if the end of the iterator is reached. - Throws:
java.io.IOException
- If there is a low-level I/O error.
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