Class Polygon

java.lang.Object
org.locationtech.jts.geom.Geometry
org.locationtech.jts.geom.Polygon
All Implemented Interfaces:
Serializable, Cloneable, Comparable, Polygonal
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).
Version:
1.7
See Also:

  • Field Details

    • 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 Details

    • 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 Details

    • getCoordinate

      public Coordinate getCoordinate()
      Description copied from class: Geometry
      Returns a vertex of this geometry (usually, but not necessarily, the first one), or null if the geometry is empty. 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:

    • 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.
      See Also:

    • 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.

      Note this test is for topological emptiness, not structural emptiness. A collection containing only empty elements is reported as empty. To check structural emptiness use Geometry.getNumGeometries().

      Specified by:
      isEmpty in class Geometry
      Returns:
      true if this Geometry does not cover any points

    • isRectangle

      public boolean isRectangle()
      Description copied from class: Geometry
      Tests whether this is a rectangular Polygon.
      Overrides:
      isRectangle in class Geometry
      Returns:
      true if the geometry is a rectangle.

    • getExteriorRing

      public LinearRing getExteriorRing()

    • getNumInteriorRing

      public int getNumInteriorRing()

    • getInteriorRingN

      public LinearRing 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:

    • 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:

    • 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()
      Deprecated.
      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

    • copyInternal

      protected Polygon copyInternal()
      Description copied from class: Geometry
      An internal method to copy subclass-specific geometry data.
      Specified by:
      copyInternal in class Geometry
      Returns:
      a copy of the target geometry object.

    • 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 Points 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.

      Specified by:
      normalize in class Geometry

    • 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

    • getTypeCode

      protected int getTypeCode()
      Specified by:
      getTypeCode in class Geometry

    • reverse

      public Polygon reverse()
      Description copied from class: Geometry
      Computes a new geometry which has all component coordinate sequences in reverse order (opposite orientation) to this one.
      Overrides:
      reverse in class Geometry
      Returns:
      a reversed geometry

    • reverseInternal

      protected Polygon reverseInternal()
      Specified by:
      reverseInternal in class Geometry