Class IIORegistry

java.lang.Object

javax.imageio.spi.ServiceRegistry

javax.imageio.spi.IIORegistry

public final class IIORegistry
extends ServiceRegistry

A registry for Image I/O service provider instances. Service provider classes may be discovered at runtime by the mechanisms documented in ServiceLoader. The intent is that it be relatively inexpensive to load and inspect all available Image I/O service provider classes. These classes may then be used to locate and instantiate more heavyweight classes that will perform actual work, in this case instances of ImageReader, ImageWriter, ImageTranscoder, ImageInputStream, and ImageOutputStream. Service providers included in the Java runtime are automatically loaded as soon as this class is instantiated.

When the registerApplicationClasspathSpis method is called, additional service provider instances will be discovered using ServiceLoader.

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 information on how to create and deploy service providers, refer to the documentation on ServiceLoader

Nested Class Summary

Nested classes/interfaces declared in class ServiceRegistry

ServiceRegistry.Filter

Modifier and Type	Class	Description
static interface	ServiceRegistry.Filter	A simple filter interface used by ServiceRegistry.getServiceProviders to select providers matching an arbitrary criterion.

Method Summary

Modifier and Type	Method	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.

Methods declared in class ServiceRegistry

contains, deregisterAll, deregisterAll, deregisterServiceProvider, deregisterServiceProvider, getCategories, getServiceProviderByClass, getServiceProviders, getServiceProviders, lookupProviders, lookupProviders, registerServiceProvider, registerServiceProvider, registerServiceProviders, setOrdering, unsetOrdering

Modifier and Type	Method	Description
boolean	contains(Object provider)	Returns true if provider is currently registered.
void	deregisterAll()	Deregisters all currently registered service providers from all categories.
void	deregisterAll(Class<?> category)	Deregisters all service provider object currently registered under the given category.
void	deregisterServiceProvider(Object provider)	Removes a service provider object from all categories that contain it.
<T> boolean	deregisterServiceProvider(T provider, Class<T> category)	Removes a service provider object from the given category.
Iterator<Class<?>>	getCategories()	Returns an Iterator of Class objects indicating the current set of categories.
<T> T	getServiceProviderByClass(Class<T> providerClass)	Returns the currently registered service provider object that is of the given class type.
<T> Iterator<T>	getServiceProviders(Class<T> category, boolean useOrdering)	Returns an Iterator containing all registered service providers in the given category.
<T> Iterator<T>	getServiceProviders(Class<T> category, ServiceRegistry.Filter filter, boolean useOrdering)	Returns an Iterator containing service provider objects within a given category that satisfy a criterion imposed by the supplied ServiceRegistry.Filter object's filter method.
static <T> Iterator<T>	lookupProviders(Class<T> providerClass)	Locates and incrementally instantiates the available providers of a given service using the context class loader.
static <T> Iterator<T>	lookupProviders(Class<T> providerClass, ClassLoader loader)	Searches for implementations of a particular service class using the given class loader.
void	registerServiceProvider(Object provider)	Adds a service provider object to the registry.
<T> boolean	registerServiceProvider(T provider, Class<T> category)	Adds a service provider object to the registry.
void	registerServiceProviders(Iterator<?> providers)	Adds a set of service provider objects, taken from an Iterator to the registry.
<T> boolean	setOrdering(Class<T> category, T firstProvider, T secondProvider)	Sets a pairwise ordering between two service provider objects within a given category.
<T> boolean	unsetOrdering(Class<T> category, T firstProvider, T secondProvider)	Sets a pairwise ordering between two service provider objects within a given category.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
protected Object	clone()	Creates and returns a copy of this object.
boolean	equals(Object obj)	Indicates whether some other object is "equal to" this one.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
final Class<?>	getClass()	Returns the runtime class of this Object.
int	hashCode()	Returns a hash code value for this object.
final void	notify()	Wakes up a single thread that is waiting on this object's monitor.
final void	notifyAll()	Wakes up all threads that are waiting on this object's monitor.
String	toString()	Returns a string representation of the object.
final void	wait()	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
final void	wait(long timeoutMillis)	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
final void	wait(long timeoutMillis, int nanos)	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Method Details

getDefaultInstance

public static IIORegistry getDefaultInstance()

Returns the default IIORegistry instance used by the Image I/O API. This instance should be used for all registry functions.

Returns:

the default registry for the Image I/O API

registerApplicationClasspathSpis

public void registerApplicationClasspathSpis()

Registers all available service providers found on the application class path, using the default ClassLoader. This method is typically invoked by the ImageIO.scanForPlugins method.

See Also:

• ImageIO.scanForPlugins()
• ClassLoader.getResources(String)