Package org.geotools.referencing.factory

Class 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:
    WKT problems

    • Constructor Detail

      • 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 Detail

      • 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.

      • 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.