Polygon

java.lang.Object
- com.vividsolutions.jts.geom.Geometry
- - com.vividsolutions.jts.geom.Polygon

All Implemented Interfaces:

Polygonal, Serializable, Cloneable, Comparable
```
public class Polygon
extends Geometry
implements Polygonal
```
Represents a polygon with linear edges, which may include holes. The outer boundary (shell) and inner boundaries (holes) of the polygon are represented by LinearRings. The boundary rings of the polygon may have any orientation. Polygons are closed, simple geometries by definition.
The polygon model conforms to the assertions specified in the OpenGIS Simple Features Specification for SQL.

A Polygon is topologically valid if and only if:
- the coordinates which define it are valid coordinates
- the linear rings for the shell and holes are valid (i.e. are closed and do not self-intersect)
- holes touch the shell or another hole at at most one point (which implies that the rings of the shell and holes must not cross)
- the interior of the polygon is connected, or equivalently no sequence of touching holes makes the interior of the polygon disconnected (i.e. effectively split the polygon into two pieces).
See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
`protected LinearRing[]`	`holes` The interior boundaries, if any.
`protected LinearRing`	`shell` The exterior boundary, or `null` if this `Polygon` is empty.

Fields inherited from class com.vividsolutions.jts.geom.Geometry
envelope, factory, SRID

Constructor Summary

Constructors

Constructor and Description
`Polygon(LinearRing shell, LinearRing[] holes, GeometryFactory factory)` Constructs a `Polygon` with the given exterior boundary and interior boundaries.
`Polygon(LinearRing shell, LinearRing[] holes, PrecisionModel precisionModel, int SRID)` Deprecated. Use GeometryFactory instead
`Polygon(LinearRing shell, PrecisionModel precisionModel, int SRID)` Deprecated. Use GeometryFactory instead

Method Summary

All Methods

Instance Methods

Concrete Methods
Modifier and Type	Method and Description
`void`	`apply(CoordinateFilter filter)` Performs an operation with or on this `Geometry`'s coordinates.
`void`	`apply(CoordinateSequenceFilter filter)` Performs an operation on the coordinates in this `Geometry`'s `CoordinateSequence`s.
`void`	`apply(GeometryComponentFilter filter)` Performs an operation with or on this Geometry and its component Geometry's.
`void`	`apply(GeometryFilter filter)` Performs an operation with or on this `Geometry` and its subelement `Geometry`s (if any).
`Object`	`clone()` Creates and returns a full copy of this `Polygon` object.
`protected int`	`compareToSameClass(Object o)` Returns whether this `Geometry` is greater than, equal to, or less than another `Geometry` having the same class.
`protected int`	`compareToSameClass(Object o, CoordinateSequenceComparator comp)` Returns whether this `Geometry` is greater than, equal to, or less than another `Geometry` of the same class.
`protected Envelope`	`computeEnvelopeInternal()` Returns the minimum and maximum x and y values in this `Geometry` , or a null `Envelope` if this `Geometry` is empty.
`Geometry`	`convexHull()` Computes the smallest convex `Polygon` that contains all the points in the `Geometry`.
`boolean`	`equalsExact(Geometry other, double tolerance)` Returns true if the two `Geometry`s are exactly equal, up to a specified distance tolerance.
`double`	`getArea()` Returns the area of this `Polygon`
`Geometry`	`getBoundary()` Computes the boundary of this geometry
`int`	`getBoundaryDimension()` Returns the dimension of this `Geometry`s inherent boundary.
`Coordinate`	`getCoordinate()` Returns a vertex of this `Geometry` (usually, but not necessarily, the first one).
`Coordinate[]`	`getCoordinates()` Returns an array containing the values of all the vertices for this geometry.
`int`	`getDimension()` Returns the dimension of this geometry.
`LineString`	`getExteriorRing()`
`String`	`getGeometryType()` Returns the name of this Geometry's actual class.
`LineString`	`getInteriorRingN(int n)`
`double`	`getLength()` Returns the perimeter of this `Polygon`
`int`	`getNumInteriorRing()`
`int`	`getNumPoints()` Returns the count of this `Geometry`s vertices.
`boolean`	`isEmpty()` Tests whether the set of points covered by this `Geometry` is empty.
`boolean`	`isRectangle()` Tests if a valid polygon is simple.
`void`	`normalize()` Converts this `Geometry` to normal form (or canonical form ).
`Geometry`	`reverse()` Computes a new geometry which has all component coordinate sequences in reverse order (opposite orientation) to this one.

Methods inherited from class com.vividsolutions.jts.geom.Geometry
buffer, buffer, buffer, checkNotGeometryCollection, compare, compareTo, compareTo, contains, coveredBy, covers, crosses, difference, disjoint, distance, equal, equals, equals, equalsExact, equalsNorm, equalsTopo, geometryChanged, geometryChangedAction, getCentroid, getEnvelope, getEnvelopeInternal, getFactory, getGeometryN, getInteriorPoint, getNumGeometries, getPrecisionModel, getSRID, getUserData, hashCode, hasNonEmptyElements, hasNullElements, intersection, intersects, isEquivalentClass, isGeometryCollection, isSimple, isValid, isWithinDistance, norm, overlaps, relate, relate, setSRID, setUserData, symDifference, toString, toText, touches, union, union, within

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail
- shell
```
protected LinearRing shell
```
  The exterior boundary, or null if this Polygon is empty.
- holes
```
protected LinearRing[] holes
```
  The interior boundaries, if any. This instance var is never null. If there are no holes, the array is of zero length.

Constructor Detail
- Polygon
```
public Polygon(LinearRing shell,
               PrecisionModel precisionModel,
               int SRID)
```
  Deprecated. Use GeometryFactory instead
  
  Constructs a Polygon with the given exterior boundary.
  
  Parameters:
  
  shell - the outer boundary of the new Polygon, or null or an empty LinearRing if the empty geometry is to be created.
  
  precisionModel - the specification of the grid of allowable points for this Polygon
  
  SRID - the ID of the Spatial Reference System used by this Polygon
- Polygon
```
public Polygon(LinearRing shell,
               LinearRing[] holes,
               PrecisionModel precisionModel,
               int SRID)
```
  Deprecated. Use GeometryFactory instead
  
  Constructs a Polygon with the given exterior boundary and interior boundaries.
  
  Parameters:
  
  shell - the outer boundary of the new Polygon, or null or an empty LinearRing if the empty geometry is to be created.
  
  holes - the inner boundaries of the new Polygon , or null or empty LinearRings if the empty geometry is to be created.
  
  precisionModel - the specification of the grid of allowable points for this Polygon
  
  SRID - the ID of the Spatial Reference System used by this Polygon
- Polygon
```
public Polygon(LinearRing shell,
               LinearRing[] holes,
               GeometryFactory factory)
```
  Constructs a Polygon with the given exterior boundary and interior boundaries.
  
  Parameters:
  
  shell - the outer boundary of the new Polygon, or null or an empty LinearRing if the empty geometry is to be created.
  
  holes - the inner boundaries of the new Polygon , or null or empty LinearRings if the empty geometry is to be created.

Method Detail

getCoordinate
```
public Coordinate getCoordinate()
```
Description copied from class: Geometry

Returns a vertex of this Geometry (usually, but not necessarily, the first one). The returned coordinate should not be assumed to be an actual Coordinate object used in the internal representation.

Specified by:

getCoordinate in class Geometry

Returns:

a Coordinate which is a vertex of this Geometry.

getCoordinates
```
public Coordinate[] getCoordinates()
```
Description copied from class: Geometry

Returns an array containing the values of all the vertices for this geometry. If the geometry is a composite, the array will contain all the vertices for the components, in the order in which the components occur in the geometry.
In general, the array cannot be assumed to be the actual internal storage for the vertices. Thus modifying the array may not modify the geometry itself. Use the CoordinateSequence.setOrdinate(int, int, double) method (possibly on the components) to modify the underlying data. If the coordinates are modified, Geometry.geometryChanged() must be called afterwards.

Specified by:

getCoordinates in class Geometry

Returns:

the vertices of this Geometry

See Also:

Geometry.geometryChanged(), CoordinateSequence.setOrdinate(int, int, double)

getNumPoints
```
public int getNumPoints()
```
Description copied from class: Geometry

Returns the count of this Geometrys vertices. The Geometry s contained by composite Geometrys must be Geometry's; that is, they must implement getNumPoints

Specified by:

getNumPoints in class Geometry

Returns:

the number of vertices in this Geometry

getDimension
```
public int getDimension()
```
Description copied from class: Geometry

Returns the dimension of this geometry. The dimension of a geometry is is the topological dimension of its embedding in the 2-D Euclidean plane. In the JTS spatial model, dimension values are in the set {0,1,2}.
Note that this is a different concept to the dimension of the vertex Coordinates. The geometry dimension can never be greater than the coordinate dimension. For example, a 0-dimensional geometry (e.g. a Point) may have a coordinate dimension of 3 (X,Y,Z).

Specified by:

getDimension in class Geometry

Returns:

the topological dimension of this geometry.

getBoundaryDimension
```
public int getBoundaryDimension()
```
Description copied from class: Geometry

Returns the dimension of this Geometrys inherent boundary.

Specified by:

getBoundaryDimension in class Geometry

Returns:

the dimension of the boundary of the class implementing this interface, whether or not this object is the empty geometry. Returns Dimension.FALSE if the boundary is the empty geometry.

isEmpty
```
public boolean isEmpty()
```
Description copied from class: Geometry

Tests whether the set of points covered by this Geometry is empty.

Specified by:

isEmpty in class Geometry

Returns:

true if this Geometry does not cover any points

isRectangle
```
public boolean isRectangle()
```
Tests if a valid polygon is simple. This method always returns true, since a valid polygon is always simple

Overrides:

isRectangle in class Geometry

Returns:

true

getExteriorRing
```
public LineString getExteriorRing()
```

getNumInteriorRing
```
public int getNumInteriorRing()
```

getInteriorRingN

public LineString getInteriorRingN(int n)

getGeometryType
```
public String getGeometryType()
```
Description copied from class: Geometry

Returns the name of this Geometry's actual class.

Specified by:

getGeometryType in class Geometry

Returns:

the name of this Geometrys actual class

getArea
```
public double getArea()
```
Returns the area of this Polygon

Overrides:

getArea in class Geometry

Returns:

the area of the polygon

getLength
```
public double getLength()
```
Returns the perimeter of this Polygon

Overrides:

getLength in class Geometry

Returns:

the perimeter of the polygon

getBoundary
```
public Geometry getBoundary()
```
Computes the boundary of this geometry

Specified by:

getBoundary in class Geometry

Returns:

a lineal geometry (which may be empty)

See Also:

Geometry.getBoundary()

computeEnvelopeInternal
```
protected Envelope computeEnvelopeInternal()
```
Description copied from class: Geometry

Returns the minimum and maximum x and y values in this Geometry , or a null Envelope if this Geometry is empty. Unlike getEnvelopeInternal, this method calculates the Envelope each time it is called; getEnvelopeInternal caches the result of this method.

Specified by:

computeEnvelopeInternal in class Geometry

Returns:

this Geometrys bounding box; if the Geometry is empty, Envelope#isNull will return true

equalsExact
```
public boolean equalsExact(Geometry other,
                           double tolerance)
```
Description copied from class: Geometry
Returns true if the two Geometrys are exactly equal, up to a specified distance tolerance. Two Geometries are exactly equal within a distance tolerance if and only if:
- they have the same structure
- they have the same values for their vertices, within the given tolerance distance, in exactly the same order.
This method does not test the values of the GeometryFactory, the SRID, or the userData fields.
To properly test equality between different geometries, it is usually necessary to Geometry.normalize() them first.
Specified by:

equalsExact in class Geometry

Parameters:

other - the Geometry with which to compare this Geometry

tolerance - distance at or below which two Coordinates are considered equal

Returns:

true if this and the other Geometry have identical structure and point values, up to the distance tolerance.

See Also:

Geometry.equalsExact(Geometry), Geometry.normalize(), Geometry.norm()

apply
```
public void apply(CoordinateFilter filter)
```
Description copied from class: Geometry

Performs an operation with or on this Geometry's coordinates. If this method modifies any coordinate values, Geometry.geometryChanged() must be called to update the geometry state. Note that you cannot use this method to modify this Geometry if its underlying CoordinateSequence's #get method returns a copy of the Coordinate, rather than the actual Coordinate stored (if it even stores Coordinate objects at all).

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply to this Geometry's coordinates

apply
```
public void apply(CoordinateSequenceFilter filter)
```
Description copied from class: Geometry

Performs an operation on the coordinates in this Geometry's CoordinateSequences. If the filter reports that a coordinate value has been changed, Geometry.geometryChanged() will be called automatically.

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply

apply
```
public void apply(GeometryFilter filter)
```
Description copied from class: Geometry

Performs an operation with or on this Geometry and its subelement Geometrys (if any). Only GeometryCollections and subclasses have subelement Geometry's.

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply to this Geometry (and its children, if it is a GeometryCollection).

apply
```
public void apply(GeometryComponentFilter filter)
```
Description copied from class: Geometry

Performs an operation with or on this Geometry and its component Geometry's. Only GeometryCollections and Polygons have component Geometry's; for Polygons they are the LinearRings of the shell and holes.

Specified by:

apply in class Geometry

Parameters:

filter - the filter to apply to this Geometry.

clone
```
public Object clone()
```
Creates and returns a full copy of this Polygon object. (including all coordinates contained by it).

Overrides:

clone in class Geometry

Returns:

a clone of this instance

convexHull

public Geometry convexHull()

Description copied from class: Geometry

Computes the smallest convex Polygon that contains all the points in the Geometry. This obviously applies only to Geometry s which contain 3 or more points; the results for degenerate cases are specified as follows:

Number of `Point`s in argument `Geometry`	`Geometry` class of result
0	empty `GeometryCollection`
1	`Point`
2	`LineString`
3 or more	`Polygon`

Overrides:: convexHull in class Geometry
Returns:: the minimum-area convex polygon containing this Geometry' s points

normalize
```
public void normalize()
```
Description copied from class: Geometry

Converts this Geometry to normal form (or canonical form ). Normal form is a unique representation for Geometry s. It can be used to test whether two Geometrys are equal in a way that is independent of the ordering of the coordinates within them. Normal form equality is a stronger condition than topological equality, but weaker than pointwise equality. The definitions for normal form use the standard lexicographical ordering for coordinates. "Sorted in order of coordinates" means the obvious extension of this ordering to sequences of coordinates.
NOTE that this method mutates the value of this geometry in-place. If this is not safe and/or wanted, the geometry should be cloned prior to normalization.

compareToSameClass
```
protected int compareToSameClass(Object o)
```
Description copied from class: Geometry

Returns whether this Geometry is greater than, equal to, or less than another Geometry having the same class.

Specified by:

compareToSameClass in class Geometry

Parameters:

o - a Geometry having the same class as this Geometry

Returns:

a positive number, 0, or a negative number, depending on whether this object is greater than, equal to, or less than o, as defined in "Normal Form For Geometry" in the JTS Technical Specifications

compareToSameClass
```
protected int compareToSameClass(Object o,
                                 CoordinateSequenceComparator comp)
```
Description copied from class: Geometry

Returns whether this Geometry is greater than, equal to, or less than another Geometry of the same class. using the given CoordinateSequenceComparator.

Specified by:

compareToSameClass in class Geometry

Parameters:

o - a Geometry having the same class as this Geometry

comp - a CoordinateSequenceComparator

Returns:

a positive number, 0, or a negative number, depending on whether this object is greater than, equal to, or less than o, as defined in "Normal Form For Geometry" in the JTS Technical Specifications

reverse
```
public Geometry reverse()
```
Description copied from class: Geometry

Computes a new geometry which has all component coordinate sequences in reverse order (opposite orientation) to this one.

Specified by:

reverse in class Geometry

Returns:

a reversed geometry

Class Polygon

Field Summary

Fields

Fields inherited from class com.vividsolutions.jts.geom.Geometry

Constructor Summary

Constructors

Method Summary

Methods inherited from class com.vividsolutions.jts.geom.Geometry

Methods inherited from class java.lang.Object

Field Detail

shell

holes

Constructor Detail

Polygon

Polygon

Polygon

Method Detail

getCoordinate

getCoordinates

getNumPoints

getDimension

getBoundaryDimension

isEmpty

isRectangle

getExteriorRing

getNumInteriorRing

getInteriorRingN

getGeometryType

getArea

getLength

getBoundary

computeEnvelopeInternal

equalsExact

apply

apply

apply

apply

clone

convexHull

normalize

compareToSameClass

compareToSameClass

reverse