Package org.geotools.referencing.factory

Class DatumAliases

Object
AbstractFactory
ReferencingFactory
DatumAliases
All Implemented Interfaces:
DatumFactory, Factory, ObjectFactory, Factory, RegistrableFactory
public class DatumAliases extends ReferencingFactory implements DatumFactory
A datum factory that add aliases to a datum name before to delegates the datum creation to an other factory. Aliases are especially important for datum since their name are often the only way to differentiate them. Two datum with different names are considered incompatible, unless some datum shift method are specified (e.g. Bursa-Wolf parameters). Unfortunatly, different softwares often use different names for the same datum, which result in OperationNotFoundException when attempting to convert coordinates from one coordinate reference system to an other one. For example "Nouvelle Triangulation Française (Paris)" and "NTF (Paris meridian)" are actually the same datum. This DatumAliases class provides a way to handle that.

DatumAliases is a class that determines if a datum name is in our list of aliases and constructs a value for the aliases property (as generic names) for a name. The default implementation is backed by the text file "DatumAliasesTable.txt". The first line in this text file must be the authority names. All other lines are the aliases.

Since DatumAliases is a datum factory, any authority factory or any WKT parser using this factory will takes advantage of the aliases table.

Since:
2.1
Author:
Rueben Schulz, Martin Desruisseaux
See Also:

  • Constructor Details

    • DatumAliases

      public DatumAliases()
      Constructs a new datum factory with the default backing factory and alias table.

    • DatumAliases

      public DatumAliases(DatumFactory factory)
      Constructs a new datum factory using the specified factory and the default alias table.
      Parameters:
      factory - The factory to use for datum creation.

    • DatumAliases

      public DatumAliases(DatumFactory factory, URL aliasURL)
      Constructs a new datum factory which delegates its work to the specified factory. The aliases table is read from the specified URL. The fist line in this file most be the authority names. All other names are aliases.
      Parameters:
      factory - The factory to use for datum creation.
      aliasURL - The url to the alias table.

  • Method Details

    • createEngineeringDatum

      public EngineeringDatum createEngineeringDatum(Map<String,?> properties) throws FactoryException
      Creates an engineering datum.
      Specified by:
      createEngineeringDatum in interface DatumFactory
      Parameters:
      properties - Name and other properties to give to the new object.
      Returns:
      The datum for the given properties.
      Throws:
      FactoryException - if the object creation failed.

    • createGeodeticDatum

      public GeodeticDatum createGeodeticDatum(Map<String,?> properties, Ellipsoid ellipsoid, PrimeMeridian primeMeridian) throws FactoryException
      Creates geodetic datum from ellipsoid and (optionaly) Bursa-Wolf parameters.
      Specified by:
      createGeodeticDatum in interface DatumFactory
      Parameters:
      properties - Name and other properties to give to the new object.
      ellipsoid - Ellipsoid to use in new geodetic datum.
      primeMeridian - Prime meridian to use in new geodetic datum.
      Returns:
      The datum for the given properties.
      Throws:
      FactoryException - if the object creation failed.

    • createImageDatum

      public ImageDatum createImageDatum(Map<String,?> properties, PixelInCell pixelInCell) throws FactoryException
      Creates an image datum.
      Specified by:
      createImageDatum in interface DatumFactory
      Parameters:
      properties - Name and other properties to give to the new object.
      pixelInCell - Specification of the way the image grid is associated with the image data attributes.
      Returns:
      The datum for the given properties.
      Throws:
      FactoryException - if the object creation failed.

    • createTemporalDatum

      public TemporalDatum createTemporalDatum(Map<String,?> properties, Date origin) throws FactoryException
      Creates a temporal datum from an enumerated type value.
      Specified by:
      createTemporalDatum in interface DatumFactory
      Parameters:
      properties - Name and other properties to give to the new object.
      origin - The date and time origin of this temporal datum.
      Returns:
      The datum for the given properties.
      Throws:
      FactoryException - if the object creation failed.

    • createVerticalDatum

      public VerticalDatum createVerticalDatum(Map<String,?> properties, VerticalDatumType type) throws FactoryException
      Creates a vertical datum from an enumerated type value.
      Specified by:
      createVerticalDatum in interface DatumFactory
      Parameters:
      properties - Name and other properties to give to the new object.
      type - The type of this vertical datum (often “geoidal”).
      Returns:
      The datum for the given properties.
      Throws:
      FactoryException - if the object creation failed.

    • createEllipsoid

      public Ellipsoid createEllipsoid(Map<String,?> properties, double semiMajorAxis, double semiMinorAxis, Unit<Length> unit) throws FactoryException
      Creates an ellipsoid from radius values.
      Specified by:
      createEllipsoid in interface DatumFactory
      Parameters:
      properties - Name and other properties to give to the new object.
      semiMajorAxis - Equatorial radius in supplied linear units.
      semiMinorAxis - Polar radius in supplied linear units.
      unit - Linear units of ellipsoid axes.
      Returns:
      The ellipsoid for the given properties.
      Throws:
      FactoryException - if the object creation failed.

    • createFlattenedSphere

      public Ellipsoid createFlattenedSphere(Map<String,?> properties, double semiMajorAxis, double inverseFlattening, Unit<Length> unit) throws FactoryException
      Creates an ellipsoid from an major radius, and inverse flattening.
      Specified by:
      createFlattenedSphere in interface DatumFactory
      Parameters:
      properties - Name and other properties to give to the new object.
      semiMajorAxis - Equatorial radius in supplied linear units.
      inverseFlattening - Eccentricity of ellipsoid.
      unit - Linear units of major axis.
      Returns:
      The ellipsoid for the given properties.
      Throws:
      FactoryException - if the object creation failed.

    • createPrimeMeridian

      public PrimeMeridian createPrimeMeridian(Map<String,?> properties, double longitude, Unit<Angle> angularUnit) throws FactoryException
      Creates a prime meridian, relative to Greenwich.
      Specified by:
      createPrimeMeridian in interface DatumFactory
      Parameters:
      properties - Name and other properties to give to the new object.
      longitude - Longitude of prime meridian in supplied angular units East of Greenwich.
      angularUnit - Angular units of longitude.
      Returns:
      The prime meridian for the given properties.
      Throws:
      FactoryException - if the object creation failed.

    • freeUnused

      public void freeUnused()
      Free all aliases that have been unused up to date. If one of those alias is needed at a later time, the aliases table will be reloaded.