org.apache.lucene.spatial
public abstract class SpatialStrategy extends Object
FieldCache
,
or some other type of cache? When?
Modifier and Type | Field and Description |
---|---|
protected com.spatial4j.core.context.SpatialContext |
ctx |
Constructor and Description |
---|
SpatialStrategy(com.spatial4j.core.context.SpatialContext ctx,
String fieldName)
Constructs the spatial strategy with its mandatory arguments.
|
Modifier and Type | Method and Description |
---|---|
abstract Field[] |
createIndexableFields(com.spatial4j.core.shape.Shape shape)
Returns the IndexableField(s) from the
shape that are to be
added to the Document . |
String |
getFieldName()
The name of the field or the prefix of them if there are multiple
fields needed internally.
|
com.spatial4j.core.context.SpatialContext |
getSpatialContext() |
ValueSource |
makeDistanceValueSource(com.spatial4j.core.shape.Point queryPoint)
See
makeDistanceValueSource(com.spatial4j.core.shape.Point, double) called with
a multiplier of 1.0 (i.e. |
abstract ValueSource |
makeDistanceValueSource(com.spatial4j.core.shape.Point queryPoint,
double multiplier)
Make a ValueSource returning the distance between the center of the
indexed shape and
queryPoint . |
abstract Filter |
makeFilter(SpatialArgs args)
|
Query |
makeQuery(SpatialArgs args)
|
ValueSource |
makeRecipDistanceValueSource(com.spatial4j.core.shape.Shape queryShape)
Returns a ValueSource with values ranging from 1 to 0, depending inversely
on the distance from
makeDistanceValueSource(com.spatial4j.core.shape.Point,double) . |
String |
toString() |
public SpatialStrategy(com.spatial4j.core.context.SpatialContext ctx, String fieldName)
public com.spatial4j.core.context.SpatialContext getSpatialContext()
public String getFieldName()
public abstract Field[] createIndexableFields(com.spatial4j.core.shape.Shape shape)
shape
that are to be
added to the Document
. These fields
are expected to be marked as indexed and not stored.
Note: If you want to store the shape as a string for retrieval in
search results, you could add it like this:
document.add(new StoredField(fieldName,ctx.toString(shape)));The particular string representation used doesn't matter to the Strategy since it doesn't use it.
UnsupportedOperationException
- if given a shape incompatible with the strategypublic ValueSource makeDistanceValueSource(com.spatial4j.core.shape.Point queryPoint)
makeDistanceValueSource(com.spatial4j.core.shape.Point, double)
called with
a multiplier of 1.0 (i.e. units of degrees).public abstract ValueSource makeDistanceValueSource(com.spatial4j.core.shape.Point queryPoint, double multiplier)
queryPoint
. If there are multiple indexed shapes
then the closest one is chosen. The result is multiplied by multiplier
, which
conveniently is used to get the desired units.public Query makeQuery(SpatialArgs args)
SpatialOperation
and Shape
from the supplied args
.
The default implementation is
return new ConstantScoreQuery(makeFilter(args));
UnsupportedOperationException
- If the strategy does not support the shape in args
UnsupportedSpatialOperation
- If the strategy does not support the SpatialOperation
in args
.public abstract Filter makeFilter(SpatialArgs args)
SpatialOperation
and Shape
from the supplied args
.
If a subclasses implements
makeQuery(org.apache.lucene.spatial.query.SpatialArgs)
then this method could be simply:
return new QueryWrapperFilter(makeQuery(args).getQuery());
UnsupportedOperationException
- If the strategy does not support the shape in args
UnsupportedSpatialOperation
- If the strategy does not support the SpatialOperation
in args
.public final ValueSource makeRecipDistanceValueSource(com.spatial4j.core.shape.Shape queryShape)
makeDistanceValueSource(com.spatial4j.core.shape.Point,double)
.
The formula is c/(d + c)
where 'd' is the distance and 'c' is
one tenth the distance to the farthest edge from the center. Thus the
scores will be 1 for indexed points at the center of the query shape and as
low as ~0.1 at its furthest edges.Copyright © 2000-2014 Apache Software Foundation. All Rights Reserved.