Java Doc for ReferencingFactoryFinder.java in  » GIS » GeoTools-2.4.1 » org » geotools » referencing » Java Source Code / Java DocumentationJava Source Code and Java Documentation

To declare a factory implementation, a services subdirectory is placed within the META-INF directory that is present in every JAR file. This directory contains a file for each factory interface that has one or more implementation classes present in the JAR file. For example, if the JAR file contained a class named com.mycompany.DatumFactoryImpl which implements the DatumFactory interface, the JAR file would contain a file named:

META-INF/services/org.opengis.referencing.datum.DatumFactory

containing the line:

com.mycompany.DatumFactoryImpl

If the factory classes implements RegisterableService , it will be notified upon registration and deregistration. Note that the factory classes should be lightweight and quick to load. Implementations of these interfaces should avoid complex dependencies on other classes and on native code. The usual pattern for more complex services is to register a lightweight proxy for the heavyweight service.

Note on factory ordering

This class is thread-safe. However, calls to any ReferencingFactoryFinder.setAuthorityOrdering or ReferencingFactoryFinder.setVendorOrdering methods have a system-wide effect. If two threads or two applications need a different ordering, they shall manage their own instance of FactoryRegistry . This FactoryFinder class is simply a convenience wrapper around a FactoryRegistry instance.

Hints that may be understood includes Hints.FORCE_LONGITUDE_FIRST_AXIS_ORDER FORCE_LONGITUDE_FIRST_AXIS_ORDER , Hints.FORCE_STANDARD_AXIS_UNITS FORCE_STANDARD_AXIS_UNITS , Hints.FORCE_STANDARD_AXIS_DIRECTIONS FORCE_STANDARD_AXIS_DIRECTIONS and Hints.VERSION VERSION .

TIP: The EPSG official factory and the EPSG extensions (additional CRS provided by ESRI and others) are two distinct factories. Call to getCRSAuthorityFactory("EPSG", null) returns only one of those, usually the official EPSG factory. If the union of those two factories is wanted, then a chain of fallbacks is wanted. Consider using something like:

(CRSAuthorityFactory.class, (hints));

Hints that may be understood includes Hints.FORCE_LONGITUDE_FIRST_AXIS_ORDER FORCE_LONGITUDE_FIRST_AXIS_ORDER , Hints.FORCE_STANDARD_AXIS_UNITS FORCE_STANDARD_AXIS_UNITS and Hints.FORCE_STANDARD_AXIS_DIRECTIONS FORCE_STANDARD_AXIS_DIRECTIONS and Hints.VERSION VERSION .
Parameters:
  authority - The desired authority (e.g. "EPSG").
Parameters:
  hints - An optional map of hints, or null if none. The first coordinate system authority factory that matches the supplied hints.
throws:
  FactoryRegistryException - if no implementation was found or can be created for theCSAuthorityFactory interface.

Hints that may be understood includes Hints.MATH_TRANSFORM_FACTORY MATH_TRANSFORM_FACTORY , Hints.DATUM_SHIFT_METHOD DATUM_SHIFT_METHOD , Hints.LENIENT_DATUM_SHIFT LENIENT_DATUM_SHIFT and Hints.VERSION VERSION .
Parameters:
  hints - An optional map of hints, or null if none. The first coordinate operation factory that matches the supplied hints.
throws:
  FactoryRegistryException - if no implementation was found or can be created for theCoordinateOperationFactory interface.

java org.geotools.referencing.FactoryFinder <options>

where options are:

Note for Windows users: If the output contains strange symbols, try to supply an " -encoding " argument. Example:

java org.geotools.referencing.FactoryFinder -encoding Cp850

The codepage number (850 in the previous example) can be obtained from the DOS commande line using the " chcp " command with no arguments. This -encoding argument need to be supplied only once.

The example below said that EPSG are preferred over ESRI ones:

FactoryFinder.setAuthorityOrdering("EPSG", "ESRI");

The example below said that an ESRI implementation (if available) is preferred over the Geotools one:

FactoryFinder.setVendorOrdering("ESRI", "Geotools");