com.spatial4j.core.context.jts

Class JtsSpatialContext

java.lang.Object

com.spatial4j.core.context.SpatialContext

com.spatial4j.core.context.jts.JtsSpatialContext

public class JtsSpatialContext
extends SpatialContext

Enhances the default SpatialContext with support for Polygons (and other geometries) using JTS. To the extent possible, our JtsGeometry adds some amount of geodetic support over vanilla JTS which only has a Euclidean (flat plane) model.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	allowMultiOverlap
protected boolean	autoIndex
protected DatelineRule	datelineRule
static JtsSpatialContext	GEO
protected com.vividsolutions.jts.geom.GeometryFactory	geometryFactory
protected boolean	useJtsLineString
protected boolean	useJtsPoint
protected ValidationRule	validationRule

Constructor Summary

Constructors

Constructor and Description
JtsSpatialContext(JtsSpatialContextFactory factory) Called by JtsSpatialContextFactory.newSpatialContext().

Method Summary

Methods

Modifier and Type	Method and Description
DatelineRule	getDatelineRule() Returns the rule used to handle geometry objects that have dateline crossing considerations.
com.vividsolutions.jts.geom.GeometryFactory	getGeometryFactory()
com.vividsolutions.jts.geom.Geometry	getGeometryFrom(Shape shape) Gets a JTS Geometry for the given Shape.
ValidationRule	getValidationRule() Returns the rule used to handle errors when creating a JTS Geometry, particularly after it has been read from one of the ShapeReaders.
boolean	isAllowMultiOverlap() If geom might be a multi geometry of some kind, then might multiple component geometries overlap? Strict OGC says this is invalid but we can accept it by computing the union.
boolean	isAutoIndex() If JtsGeometry shapes should be automatically "prepared" (i.e.
Shape	makeLineString(List<Point> points) Constructs a line string.
Point	makePoint(double x, double y) Construct a point.
Rectangle	makeRectFromRectangularPoly(com.vividsolutions.jts.geom.Geometry geom) INTERNAL: Returns a Rectangle of the JTS Envelope (bounding box) of the given geom.
JtsGeometry	makeShape(com.vividsolutions.jts.geom.Geometry geom) INTERNAL: Creates a Shape from a JTS Geometry.
JtsGeometry	makeShape(com.vividsolutions.jts.geom.Geometry geom, boolean dateline180Check, boolean allowMultiOverlap) INTERNAL
Shape	makeShapeFromGeometry(com.vividsolutions.jts.geom.Geometry geom) INTERNAL Usually creates a JtsGeometry, potentially validating, repairing, and indexing ("preparing").
double	normX(double x) Normalize the 'x' dimension.
double	normY(double y) Normalize the 'y' dimension.
String	toString()
String	toString(Shape shape) Writes the shape to a String using the old/deprecated LegacyShapeWriter.
boolean	useJtsLineString() Should makeLineString(java.util.List) return JtsGeometry?
boolean	useJtsPoint() Should makePoint(double, double) return JtsPoint?

Methods inherited from class com.spatial4j.core.context.SpatialContext

calcDistance, calcDistance, getBinaryCodec, getDistCalc, getFormats, getWktShapeParser, getWorldBounds, isGeo, isNormWrapLongitude, makeBufferedLineString, makeCircle, makeCircle, makeCollection, makeRectangle, makeRectangle, readShape, readShapeFromWkt, verifyX, verifyY

Methods inherited from class java.lang.Object

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

Field Detail

GEO

public static final JtsSpatialContext GEO

geometryFactory

protected final com.vividsolutions.jts.geom.GeometryFactory geometryFactory

allowMultiOverlap

protected final boolean allowMultiOverlap

useJtsPoint

protected final boolean useJtsPoint

useJtsLineString

protected final boolean useJtsLineString

datelineRule

protected final DatelineRule datelineRule

validationRule

protected final ValidationRule validationRule

autoIndex

protected final boolean autoIndex

Constructor Detail

JtsSpatialContext

public JtsSpatialContext(JtsSpatialContextFactory factory)

Called by JtsSpatialContextFactory.newSpatialContext().

Method Detail

isAllowMultiOverlap

public boolean isAllowMultiOverlap()

If geom might be a multi geometry of some kind, then might multiple component geometries overlap? Strict OGC says this is invalid but we can accept it by computing the union. Note: Our ShapeCollection mostly doesn't care but it has a method related to this ShapeCollection.relateContainsShortCircuits().

getDatelineRule

public DatelineRule getDatelineRule()

Returns the rule used to handle geometry objects that have dateline crossing considerations.

getValidationRule

public ValidationRule getValidationRule()

Returns the rule used to handle errors when creating a JTS Geometry, particularly after it has been read from one of the ShapeReaders.

isAutoIndex

public boolean isAutoIndex()

If JtsGeometry shapes should be automatically "prepared" (i.e. optimized) when read via from a ShapeReader.

See Also:

JtsGeometry.index()

normX

public double normX(double x)

Description copied from class: SpatialContext

Normalize the 'x' dimension. Might reduce precision or wrap it to be within the bounds. This is called by WKTReader before creating a shape.

Overrides:

normX in class SpatialContext

normY

public double normY(double y)

Description copied from class: SpatialContext

Normalize the 'y' dimension. Might reduce precision or wrap it to be within the bounds. This is called by WKTReader before creating a shape.

Overrides:

normY in class SpatialContext

toString

public String toString(Shape shape)

Description copied from class: SpatialContext

Writes the shape to a String using the old/deprecated LegacyShapeWriter. The JTS based subclass will write it to WKT if the legacy format doesn't support that shape. Spatial4j in the near future won't support writing shapes to strings.

Overrides:

toString in class SpatialContext

Parameters:

shape - non-null

Returns:

non-null

getGeometryFrom

public com.vividsolutions.jts.geom.Geometry getGeometryFrom(Shape shape)

Gets a JTS Geometry for the given Shape. Some shapes hold a JTS geometry whereas new ones must be created for the rest.

Parameters:

shape - Not null

Returns:

Not null

useJtsPoint

public boolean useJtsPoint()

Should makePoint(double, double) return JtsPoint?

makePoint

public Point makePoint(double x,
              double y)

Description copied from class: SpatialContext

Construct a point.

Overrides:

makePoint in class SpatialContext

useJtsLineString

public boolean useJtsLineString()

Should makeLineString(java.util.List) return JtsGeometry?

makeLineString

public Shape makeLineString(List<Point> points)

Description copied from class: SpatialContext

Constructs a line string. It's an ordered sequence of connected vertexes. There is no official shape/interface for it yet so we just return Shape.

Overrides:

makeLineString in class SpatialContext

makeShapeFromGeometry

public Shape makeShapeFromGeometry(com.vividsolutions.jts.geom.Geometry geom)

INTERNAL Usually creates a JtsGeometry, potentially validating, repairing, and indexing ("preparing"). This method is intended for use by ShapeReader instances. If given a direct instance of GeometryCollection then it's contents will be recursively converted and then the resulting list will be passed to SpatialContext.makeCollection(List) and returned. If given a Point then SpatialContext.makePoint(double, double) is called, which will return a JtsPoint if useJtsPoint(); otherwise a standard Spatial4j Point is returned. If given a LineString and if useJtsLineString() is true then then the geometry's parts are exposed to call SpatialContext.makeLineString(List).

makeShape

public JtsGeometry makeShape(com.vividsolutions.jts.geom.Geometry geom,
                    boolean dateline180Check,
                    boolean allowMultiOverlap)

INTERNAL

Parameters:

geom - Non-null

dateline180Check - if both this is true and SpatialContext.isGeo(), then JtsGeometry will check for adjacent coordinates greater than 180 degrees longitude apart, and it will do tricks to make that line segment (and the shape as a whole) cross the dateline even though JTS doesn't have geodetic support.

allowMultiOverlap - See isAllowMultiOverlap().

See Also:

makeShape(com.vividsolutions.jts.geom.Geometry)

makeShape

public JtsGeometry makeShape(com.vividsolutions.jts.geom.Geometry geom)

INTERNAL: Creates a Shape from a JTS Geometry. Generally, this shouldn't be called when one of the other factory methods are available, such as for points. The caller needs to have done some verification/normalization of the coordinates by now, if any. Also, note that direct instances of GeometryCollection isn't supported. Instead of calling this method, consider JtsWKTReader#makeShapeFromGeometry(Geometry) which

getGeometryFactory

public com.vividsolutions.jts.geom.GeometryFactory getGeometryFactory()

toString

public String toString()

Overrides:

toString in class SpatialContext

makeRectFromRectangularPoly

public Rectangle makeRectFromRectangularPoly(com.vividsolutions.jts.geom.Geometry geom)

INTERNAL: Returns a Rectangle of the JTS Envelope (bounding box) of the given geom. This asserts that Geometry.isRectangle() is true. This method reacts to the DatelineRule setting.

Parameters:

geom - non-null

Returns:

null equivalent Rectangle.