Package org.apache.lucene.search
Class LongValuesSource
- java.lang.Object
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- org.apache.lucene.search.LongValuesSource
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- All Implemented Interfaces:
SegmentCacheable
public abstract class LongValuesSource extends Object implements SegmentCacheable
Base class for producingLongValues
To obtain aLongValues
object for a leaf reader, clients should callrewrite(IndexSearcher)
against the top-level searcher, and thengetValues(LeafReaderContext, DoubleValues)
. LongValuesSource objects for long and int-valued NumericDocValues fields can be obtained by callingfromLongField(String)
andfromIntField(String)
. To obtain a LongValuesSource from a float or double-valued NumericDocValues field, useDoubleValuesSource.fromFloatField(String)
orDoubleValuesSource.fromDoubleField(String)
and then callDoubleValuesSource.toLongValuesSource()
.
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Constructor Summary
Constructors Constructor Description LongValuesSource()
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Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description static LongValuesSource
constant(long value)
Creates a LongValuesSource that always returns a constant valueabstract boolean
equals(Object obj)
static LongValuesSource
fromIntField(String field)
Creates a LongValuesSource that wraps an int-valued fieldstatic LongValuesSource
fromLongField(String field)
Creates a LongValuesSource that wraps a long-valued fieldSortField
getSortField(boolean reverse)
Create a sort field based on the value of this producerabstract LongValues
getValues(LeafReaderContext ctx, DoubleValues scores)
Returns aLongValues
instance for the passed-in LeafReaderContext and scores If scores are not needed to calculate the values (iereturns false
, callers may safely passnull
for thescores
parameter.abstract int
hashCode()
abstract boolean
needsScores()
Return true if document scores are needed to calculate valuesabstract LongValuesSource
rewrite(IndexSearcher searcher)
Return a LongValuesSource specialised for the given IndexSearcher Implementations should assume that this will only be called once.DoubleValuesSource
toDoubleValuesSource()
Convert to a DoubleValuesSource by casting long values to doublesabstract String
toString()
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.apache.lucene.search.SegmentCacheable
isCacheable
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Method Detail
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getValues
public abstract LongValues getValues(LeafReaderContext ctx, DoubleValues scores) throws IOException
Returns aLongValues
instance for the passed-in LeafReaderContext and scores If scores are not needed to calculate the values (iereturns false
, callers may safely passnull
for thescores
parameter.- Throws:
IOException
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needsScores
public abstract boolean needsScores()
Return true if document scores are needed to calculate values
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rewrite
public abstract LongValuesSource rewrite(IndexSearcher searcher) throws IOException
Return a LongValuesSource specialised for the given IndexSearcher Implementations should assume that this will only be called once. IndexSearcher-independent implementations can just returnthis
- Throws:
IOException
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getSortField
public SortField getSortField(boolean reverse)
Create a sort field based on the value of this producer- Parameters:
reverse
- true if the sort should be decreasing
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toDoubleValuesSource
public DoubleValuesSource toDoubleValuesSource()
Convert to a DoubleValuesSource by casting long values to doubles
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fromLongField
public static LongValuesSource fromLongField(String field)
Creates a LongValuesSource that wraps a long-valued field
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fromIntField
public static LongValuesSource fromIntField(String field)
Creates a LongValuesSource that wraps an int-valued field
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constant
public static LongValuesSource constant(long value)
Creates a LongValuesSource that always returns a constant value
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