Java Doc for SDO.java in  » GIS » GeoTools-2.4.1 » org » geotools » data » oracle » sdo » Java Source Code / Java DocumentationJava Source Code and Java Documentation

Provide utility functions for working with JTS Geometries in terms Oracle Spatial Data Objects

This class can be used for normal JTS Geometry persistence with little fuss and bother - please see GeometryConverter for an example of this.

With a little fuss and bother LRS information can also be handled. Although it is very rare that JTS makes use of such things.

L represents support for LRS (Liniar Referencing System?).

SRID code representing Spatial Reference System.

CoordinateSequence & CoordinateAccess wil be used to determine the dimension, and the number of ordinates added.

Helpful when dealing construction Geometries with your own Coordiante Types.

Describes how to use Ordinates to represent Geometry.

Describes how Ordinates are ordered:

 Value Elements Meaning
 0           Custom Geometry (like spline) 
 1  simple   Point (or Points)
 2  simple   Line (or Lines)
 3           polygon ring of unknown order (discouraged update to 1003 or 2003)
 1003  simple   polygon ring (1 exterior counterclockwise order)
 2003  simple   polygon ring (2 interior clockwise order)
 4  compound series defines a linestring
 5  compound series defines a polygon ring of unknown order (discouraged)
 1005  compound series defines exterior polygon ring (counterclockwise order)
 2005  compound series defines interior polygon ring (clockwise order)
 

Keep in mind:

• simple elements are defined by a single triplet entry in the SDO_ELEM_INFO array
• compound elements are defined by a header triplet, and a series of triplets for the parts.

Describes ordinates as part of SDO_ELEM_INFO array.

• compound element:(SDO_ETYPE 4, 1005, or 2005)
  Number of subsequent triplets are part of compound element
• simple element:(SDE_ELEM 1, 2, 1003, or 2003)
  Code defines how ordinates are interpreted (lines or curves)

SDO_INTERPRETAION Values: (from Table 2-2 in reference docs)

 SDO_ETYPE Value    Meaning
 0         anything Custom Geometry
 1         1        Point
 1         N > 1    N points
 2         1        LineString of straight lines
 2         2        LineString connected by circ arcs (start,any,end pt)
 1003/2003 1        Polygon Edged with straight lines
 1003/2003 2        Polygon Edged with circ arcs (start, any, end pt)
 1003/2003 3        Non SRID rectangle defined by (bottomleft,topright pt)
 1003/2003 4        Circle defined by three points on circumference
 4         N > 1    Compound Line String made of N (ETYPE=2) lines and arcs
 1005/2005 N > 1    Polygon defined by (ETYPE=2) lines and arcs
 

When playing with circular arcs (SDO_INTERPRETATION==2) arcs are defined by three points.

Encoding of Geometry type and dimension.

SDO_GTYPE defined as for digits [d][l][tt]:

• d: number of dimensions (limited to 2,3, or 4)
• l: measure representation (ordinate 3 or 4) or 0 to represent none/last
• tt: See the TT.

Will return non null for Point objects.

For normal JTS Geometry this will be 2 or 3 depending if geom.getCoordinate.z is Double.NaN.

Subclasses may override as required.

L represents support for LRS (Liniar Referencing System?). JTS Geometry objects do not support LRS so this will be 0.

Subclasses may override as required.

SRID code representing Spatial Reference System. SRID number used must be defined in the Oracle MDSYS.CS_SRS table.

SRID_NULLrepresents lack of coordinate system.

TT is used to represent the type of the JTS Geometry:

 Value Geometry Type    JTS Geometry
 00    UNKNOWN_GEOMETRY null
 01    POINT            Point
 02    LINE             LineString
 CURVE            not supported
 03    POLYGON          Polygon
 04    COLLECTION       GeometryCollection
 05    MULTIPOINT       MultiPoint
 06    MULTILINE        MultiLineString
 MULTICURVE       not supported
 07    MULTIPOLYGON     MultiPolygon
 

To produce two dimension Coordiantes pass in null for z

To produce two dimension Coordiantes pass in null for z

To produce two dimension Coordiantes pass in null for z

To produce two dimension Coordiantes pass in null for z

CoordinateSequence & CoordinateAccess wil be used to determine the dimension, and the number of ordinates added.

GTYPE encodes the following information:

• D: Dimension of ordinates
• L: Dimension of LRS measures

The number of ordinates per coordinate are taken to be L+D, and the number of ordinates should be a multiple of this value.

In the Special case of GTYPE 2001 and a three ordinates are interpreted as a single Coordinate rather than an error.

If the Coordiante need to be reversed a copy will be returned.

Helpful when dealing construction Geometries with your own Coordiante Types. The dimensionality specified in GTYPE will be used to interpret the offsets in elemInfo.

Describes how to use Ordinates to represent Geometry.

 # Name                Meaning
 0 SDO_STARTING_OFFSET Offsets start at one
 1 SDO_ETYPE           Describes how ordinates are ordered
 2 SDO_INTERPRETATION  SDO_ETYPE: 4, 1005, or 2005
 Number of triplets involved in compound geometry
 SDO_ETYPE: 1, 2, 1003, or 2003
 Describes ordering of ordinates in geometry  
 

For compound elements (SDO_ETYPE values 4 and 5) the last element of one is the first element of the next.

Describes how Ordinates are ordered:

 Value Elements Meaning
 0           Custom Geometry (like spline) 
 1  simple   Point (or Points)
 2  simple   Line (or Lines)
 3           polygon ring of unknown order (discouraged update to 1003 or 2003)
 1003  simple   polygon ring (1 exterior counterclockwise order)
 2003  simple   polygon ring (2 interior clockwise order)
 4  compound series defines a linestring
 5  compound series defines a polygon ring of unknown order (discouraged)
 1005  compound series defines exterior polygon ring (counterclockwise order)
 2005  compound series defines interior polygon ring (clockwise order)
 

Keep in mind:

• simple elements are defined by a single triplet entry in the SDO_ELEM_INFO array
• compound elements are defined by a header triplet, and a series of triplets for the parts. Elements in a compound element share first and last points.
• We are not allowed to mix 1 digit and 4 digit values for ETYPE and GTYPE in a single geometry

This whole mess describes ordinates as part of SDO_ELEM_INFO array. data type.

Describes ordinates as part of SDO_ELEM_INFO array.

• compound element:(SDO_ETYPE 4, 1005, or 2005)
  Number of subsequent triplets are part of compound element
• simple element:(SDE_ELEM 1, 2, 1003, or 2003)
  Code defines how ordinates are interpreted (lines or curves)

SDO_INTERPRETAION Values: (from Table 2-2 in reference docs)

 SDO_ETYPE Value    Meaning
 0         anything Custom Geometry
 1         1        Point
 1         N > 1    N points
 2         1        LineString of straight lines
 2         2        LineString connected by circ arcs (start,any,end pt)
 1003/2003 1        Polygon Edged with straight lines
 1003/2003 2        Polygon Edged with circ arcs (start, any, end pt)
 1003/2003 3        Non SRID rectangle defined by (bottomleft,topright pt)
 1003/2003 4        Circle defined by three points on circumference
 4         N > 1    Compound Line String made of N (ETYPE=2) lines and arcs
 1005/2005 N > 1    Polygon defined by (ETYPE=2) lines and arcs
 

When playing with circular arcs (SDO_INTERPRETATION==2) arcs are defined by three points. A start point, any point on the arc and the end point. The last point of an arc is the start point of the next. When used to describe a polygon (SDO_ETYPE==1003 or 2003) the first and last point must be the same.

Provides the INTERPRETATION value for the ELEM_INFO triplet of (STARTING_OFFSET, ETYPE, INTERPRETATION).

Starting offsets start from one.

Describes ordinates as part of SDO_ELEM_INFO data type.

Encoding of Geometry type and dimension.

SDO_GTYPE defined as for digits [d][l][tt]:

• d: number of dimensions (limited to 2,3, or 4)
• l: measure representation (ordinate 3 or 4) or 0 to represent none/last
• tt: See the TT. constants defined in this class

Definition provided by Oracle Spatial User�s Guide and Reference.

Example numbering: for (x y g m) dimension==2, measure==2

• 0: x ordinate array
• 1: y ordinate array
• 2: g ordinate array
• 3: m ordinate array

CoordianteAccess is required for additional ordinates.

Ordinate limitied to:

• 0: x ordinate array
• 1: y ordinate array
• 2: z ordinate array
• 3: empty ordinate array

Please see SDO_ETYPE, SDO_INTERPRETATION and SDO_GTYPE for description of how these ordinates are to be interpreted.

Ordinates are ordered by Dimension are non null:

• Two Dimensional:

  {x1,y1,x2,y2,...}

• Three Dimensional:

  {x1,y1,z1,x2,y2,z2,...}

Spatial will siliently detect and ignore the following:

• d001 point/d005 multipoint elements that are not SDO_ETYPE==1 points
• d002 lines or curve/d006 multilines or multicurve elements that are not SDO_ETYPE==2 lines or SDO_ETYPE==4 arcs
• d003 polygon/d007 multipolygon elements that are not SDO_ETYPE==3 unordered polygon lines or SDO_ETYPE==5 unorderd compound polygon ring are ignored

While Oracle is silient on these errors - all other errors will not be detected!

Ordinates are placed into an array based on:

• geometryGTypeD - chooses between 2d and 3d representation
• geometryGTypeL - number of LRS measures

No assumptions are made about the order

Will return non null for Point objects. null is returned for all non point objects.

You cannot use this with LRS Coordiantes

Subclasses may wish to repress this method and force Points to be represented using SDO_ORDINATES.