Package org.apache.lucene.spatial.serialized

# Class SerializedDVStrategy

java.lang.Object
org.apache.lucene.spatial.SpatialStrategy
org.apache.lucene.spatial.serialized.SerializedDVStrategy

public class SerializedDVStrategy extends SpatialStrategy
A SpatialStrategy based on serializing a Shape stored into BinaryDocValues. This is not at all fast; it's designed to be used in conjunction with another index based SpatialStrategy that is approximated (like `RecursivePrefixTreeStrategy`) to add precision or eventually make more specific / advanced calculations on the per-document geometry. The serialization uses Spatial4j's `BinaryCodec`.

WARNING: This API is experimental and might change in incompatible ways in the next release.

- ## Field Summary

  ### Fields inherited from class org.apache.lucene.spatial.SpatialStrategy

  `ctx`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `SerializedDVStrategy(org.locationtech.spatial4j.context.SpatialContext ctx, String fieldName)`
  Constructs the spatial strategy with its mandatory arguments.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `Field[]`
  `createIndexableFields(org.locationtech.spatial4j.shape.Shape shape)`
  Returns the IndexableField(s) from the `shape` that are to be added to the `Document`.
  `DoubleValuesSource`
  `makeDistanceValueSource(org.locationtech.spatial4j.shape.Point queryPoint, double multiplier)`
  Make a ValueSource returning the distance between the center of the indexed shape and `queryPoint`.
  `Query`
  `makeQuery(SpatialArgs args)`
  Returns a Query that should be used in a random-access fashion.
  `ShapeValuesSource`
  `makeShapeValueSource()`
  Provides access to each shape per document

  ### Methods inherited from class org.apache.lucene.spatial.SpatialStrategy

  `getFieldName, getSpatialContext, makeDistanceValueSource, makeRecipDistanceValueSource, toString`

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- ## Constructor Details

  - ### SerializedDVStrategy

    public SerializedDVStrategy(org.locationtech.spatial4j.context.SpatialContext ctx, String fieldName)
    Constructs the spatial strategy with its mandatory arguments.

- ## Method Details

  - ### createIndexableFields

    public Field[] createIndexableFields(org.locationtech.spatial4j.shape.Shape shape)
    Description copied from class: `SpatialStrategy`
    Returns the IndexableField(s) from the `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.
    Specified by:
      `createIndexableFields` in class `SpatialStrategy`
    Returns:
      Not null nor will it have null elements.

  - ### makeDistanceValueSource

    public DoubleValuesSource makeDistanceValueSource(org.locationtech.spatial4j.shape.Point queryPoint, double multiplier)
    Description copied from class: `SpatialStrategy`
    Make a ValueSource returning the distance between the center of the indexed shape and `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.
    Specified by:
      `makeDistanceValueSource` in class `SpatialStrategy`

  - ### makeQuery

    public Query makeQuery(SpatialArgs args)
    Returns a Query that should be used in a random-access fashion. Use in another manner will be SLOW.
    Specified by:
      `makeQuery` in class `SpatialStrategy`

  - ### makeShapeValueSource

    public ShapeValuesSource makeShapeValueSource()
    Provides access to each shape per document