| An interface definition to aid in the automatic loading of
user-defined JAI operations.
All concrete classes that implement this
interface can register by listing themselves in the
"META-INF/services/javax.media.jai.OperationRegistrySpi"
file that can be found in the classpath (this file is often contained
in a jar file along with the class files). The file should contain
a list of fully-qualified concrete provider-class names, one per
line. Space and tab characters surrounding each name, as well as
blank lines, are ignored. The comment character is '#'
(0x23); on each line all characters following the first
comment character are ignored. The file must be encoded in UTF-8.
If a particular concrete provider class is named in more than one
configuration file, or is named in the same configuration file more
than once, then the duplicates will be ignored. The configuration
file naming a particular provider need not be in the same jar file or
other distribution unit as the provider itself. The provider must be
accessible from the same class loader that was initially queried to
locate the configuration file; note that this is not necessarily the
class loader that found the file.
All such concrete classes must have a zero-argument
constructor so that they may be instantiated during lookup. The
updateRegistry() method of all such registered
classes will be called with the default instance of the JAI
OperationRegistry after it has been initialized with the
default JAI registry file (META-INF/javax.media.jai.registryFile.jai)
and once all "META-INF/registryFile.jai"s found in the
classpath are loaded. There is no guarantee of the order
in which the updateRegistry() method of each
OperationRegistrySpi instance will be invoked.
The OperationRegistrySpi could also be used to for
the registration of other JAI related objects done through static
methods such as the Serializer objects and image
codecs.
See Also: javax.media.jai.remote.Serializer
See Also: javax.media.jai.OperationRegistry
See Also: javax.media.jai.OperationRegistry.writeExternal
since:
JAI 1.1 |