public final class IIORegistry extends ServiceRegistry
ImageReader,
ImageWriter, ImageTranscoder,
ImageInputStream, and ImageOutputStream.
Service providers found on the system classpath (typically
the lib/ext directory in the Java
installation directory) are automatically loaded as soon as this class is
instantiated.
When the registerApplicationClasspathSpis method
is called, service provider instances declared in the
meta-information section of JAR files on the application class path
are loaded. To declare a service provider, a services
subdirectory is placed within the META-INF directory
that is present in every JAR file. This directory contains a file
for each service provider 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.imageio.MyFormatReaderSpi which
implements the ImageReaderSpi interface, the JAR file
would contain a file named:
META-INF/services/javax.imageio.spi.ImageReaderSpicontaining the line:
com.mycompany.imageio.MyFormatReaderSpi
The service provider classes are intended to be lightweight and quick to load. Implementations of these interfaces should avoid complex dependencies on other classes and on native code.
It is also possible to manually add service providers not found
automatically, as well as to remove those that are using the
interfaces of the ServiceRegistry class. Thus
the application may customize the contents of the registry as it
sees fit.
For more details on declaring service providers, and the JAR format in general, see the JAR File Specification.
ServiceRegistry.Filter| Modifier and Type | Method and Description |
|---|---|
static IIORegistry |
getDefaultInstance()
Returns the default
IIORegistry instance used by
the Image I/O API. |
void |
registerApplicationClasspathSpis()
Registers all available service providers found on the
application class path, using the default
ClassLoader. |
contains, deregisterAll, deregisterAll, deregisterServiceProvider, deregisterServiceProvider, finalize, getCategories, getServiceProviderByClass, getServiceProviders, getServiceProviders, lookupProviders, lookupProviders, registerServiceProvider, registerServiceProvider, registerServiceProviders, setOrdering, unsetOrderingpublic static IIORegistry getDefaultInstance()
IIORegistry instance used by
the Image I/O API. This instance should be used for all
registry functions.
Each ThreadGroup will receive its own
instance; this allows different Applets in the
same browser (for example) to each have their own registry.
ThreadGroup.public void registerApplicationClasspathSpis()
ClassLoader. This method is typically invoked by
the ImageIO.scanForPlugins method. Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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