public final class IIORegistry extends ServiceRegistryA registry for service provider instances. Service provider classes may be detected at run time by means of meta-information in the JAR files containing them. The intent is that it be relatively inexpensive to load and inspect all available service provider classes. These classes may them be used to locate and instantiate more heavyweight classes that will perform actual work, in this case instances of
ImageOutputStream. Service providers found from the Java platform are automatically loaded as soon as this class is instantiated.
registerApplicationClasspathSpismethod 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
servicessubdirectory is placed within the
META-INFdirectory 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.MyFormatReaderSpiwhich implements the
ImageReaderSpiinterface, the JAR file would contain a file named:
META-INF/services/javax.imageio.spi.ImageReaderSpicontaining the line:
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
ServiceRegistryclass. 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.
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description
getDefaultInstance()Returns the default
IIORegistryinstance used by the Image I/O API.
registerApplicationClasspathSpis()Registers all available service providers found on the application class path, using the default
Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from class javax.imageio.spi.ServiceRegistry
contains, deregisterAll, deregisterAll, deregisterServiceProvider, deregisterServiceProvider, finalize, getCategories, getServiceProviderByClass, getServiceProviders, getServiceProviders, lookupProviders, lookupProviders, registerServiceProvider, registerServiceProvider, registerServiceProviders, setOrdering, unsetOrdering
public static IIORegistry getDefaultInstance()Returns the default
IIORegistryinstance used by the Image I/O API. This instance should be used for all registry functions.
ThreadGroupwill receive its own instance; this allows different
Applets in the same browser (for example) to each have their own registry.
- the default registry for the current
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