Package net.sf.eBusx.geo

Class GeoPolygon

java.lang.Object

net.sf.eBus.messages.EMessageObject

net.sf.eBus.messages.EField

net.sf.eBusx.geo.GeoObject

net.sf.eBusx.geo.GeoPolygon

All Implemented Interfaces:

java.io.Serializable

public final class GeoPolygon
extends GeoObject

A polygon is one or more linear rings and a linear ring is a LineString meeting the following constraints:

• Has four or more closed positions.
• First and last positions are equivalent, and must contain identical values; their representation should also be identical.
• Is a boundary of a surface or the boundary of a hole in a surface.
• Must follow the right-hand rule with respect to the area it bounds, i.e., exterior rings are counterclockwise, and holes are clockwise.

(Note: GeoJSON Format Specification (June, 2008) did not discuss linear ring winding order. For backwards compatibility, parsers should not reject Polygons that do not follow the right-hand rule.)

Although a linear ring is not explicitly represented as a GeoJSON geometry type, it leads to a canonical formulation of the Polygon geometry type definition as follows:

• For type "Polygon", the "coordinates" member must be an array of linear rings.
• For Polygons with more than one of these rings, the first must be the exterior ring, and any others must be interior rings. The exterior ring bounds the surface, and the interior rings (if present) bound holes within the surface.

Note: GeoPolygon does not enforce the linear rings requirement. This means that an invalid set of LineStrings which do not form linear rings may be entered. If you wish to transmit a random list of line strings please use GeoLineString instead.

Author:

Charles W. Rapp

See Also:

GeoMultiLineString, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	GeoPolygon.Builder	Builder class used to create GeoPolygon instances.

Nested classes/interfaces inherited from class net.sf.eBusx.geo.GeoObject

GeoObject.GeoBuilder<F extends GeoObject,B extends GeoObject.GeoBuilder<F,?>>, GeoObject.GeoType

Field Summary

Fields

Modifier and Type	Field	Description
LineString[]	linearRings	Array of one or more linear rings defining polygon.

Fields inherited from class net.sf.eBusx.geo.GeoObject

boundingBox, MAX_LATITUDE, MAX_LONGITUDE, MIN_LATITUDE, MIN_LONGITUDE, type

Method Summary

Modifier and Type	Method	Description
static GeoPolygon.Builder	builder()	Returns a new GeoJSON polygon builder instance.
boolean	equals(java.lang.Object o)	Returns true if o is a non-nuull GeoPolygon with a lineear ring array equaling this GeoPolygo linear ring array.
int	hashCode()	Returns hash code based on contained linear rings.
java.lang.String	toString()	Returns text containing linear rings defining the polygon.

Methods inherited from class net.sf.eBusx.geo.GeoObject

validateLatitude, validateLongitude

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

linearRings

public final LineString[] linearRings

Array of one or more linear rings defining polygon.

Method Detail

toString

public java.lang.String toString()

Returns text containing linear rings defining the polygon.

Overrides:

toString in class GeoObject

Returns:

polygon as human-readable text.

equals

public boolean equals(java.lang.Object o)

Returns true if o is a non-nuull GeoPolygon with a lineear ring array equaling this GeoPolygo linear ring array. Otherwise returns false.

Overrides:

equals in class java.lang.Object

Parameters:

o - comparison object.

Returns:

true if o equals this object.

hashCode

public int hashCode()

Returns hash code based on contained linear rings.

Overrides:

hashCode in class java.lang.Object

Returns:

linear rings hash code.

builder

public static GeoPolygon.Builder builder()

Returns a new GeoJSON polygon builder instance.

Returns:

new polygon builder instance.