A marker interface for factories that are buffering their objects in some way.
Base interface for Geotools factories (i.e. service discovery).
Provides iterators over factories of specified categories.
This class should be a marker interface instead of an
An optional factory that may not be available in all configurations.
Skeletal implementation of factories.
Defines a common abstraction for getting the different factories.
Defines static methods used to access the application's default implementation for some common factories.
A factory registry capable to creates factories if no appropriate instance was found in the registry.
Base class for factory finders.
A registry for factories, organized by categories (usualy by interface).
Static methods relative to the global GeoTools configuration.
A set of hints providing control on factories to be used.
A key for value that may be specified either as instance of
Keys for extra configuration options that are passed from the overhead application into queries.
A hint used to capture a configuration setting as double.
Key for hints to be specified as a
A hint used to capture a configuration setting as an integer.
The type for keys used to control various aspects of the factory creation.
Key that allows the choice of several options.
Thrown when a factory can't be found in the registery.
Thrown when a factory can't be found or can't be instantiate.
Because Geotools core API consists almost exclusively of interfaces (including GeoAPI), factories play a role in how developers use the API. Although the interfaces that are declared in GeoAPI are implemented in various Geotools packages you should not use those classes directly. Instead you should use factories.
ServiceRegistry provides a general
way (even if it is defined in a
javax.imageio subpackage) to instantiate and
manage factories (also called providers). Each factory implementation should be declared
META-INF/services directory, usually bundled in every JAR file. For example
if a JAR file provides one or more
implementations, then it must provide the following file:
with a content similar to the one below:
com.mycompany.MyDatumFactory1 com.mycompany.MyDatumFactory2 com.mycompany.MyDatumFactory3
The ordering is initially unspecified. Users can
set an ordering
explicitly themselves, or implementations can do that automatically
AbstractFactory class provides a simple way to setup ordering
on registration on the basis of a priority
If a user wants a specific implementation, he can
iterates through registered ones
and pickup the desired implementation himself. An alternative is to bundle the criterions in a
map of hints and lets the registry selects an implementation
accordingly. This later functionality is not provided by the standard
but is provided by Geotools's
FactoryRegistry extension. This class extends
the service registry API with the following functionalities:
scanForPlugins() method that scans for plugins in the
registry class loader, the
thread context class loader and the
system class loader.
scanForPlugins() looks for any implementation specified as
When more than one implementation is available for the same
subinterface, an optional set of hints can specifies the criterions that the
desired implementation must meets. If a factory implementation depends on other factories, the dependencies hints
are checked recursively.
Optionally, if no factory matches the given hints, a new instance can be automatically created.
Note that the hints, if provided, don't need to apply
directly to the requested factory category. They may apply indirectly through some dependency. A typical example is
a request for any
GeometryFactory instance, providing that this instance uses a
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