- All Superinterfaces:
The JNDI framework allows for object implementations to
be loaded in dynamically via object factories. See
ObjectFactory for details.
ObjectFactory by allowing
to be supplied to the
DirObjectFactory implementations are intended to be used by
service providers. The service provider, in addition reading an
object from the directory, might already have attributes that
are useful for the object factory to check to see whether the
factory is supposed to process the object. For instance, an LDAP-style
service provider might have read the "objectclass" of the object.
A CORBA object factory might be interested only in LDAP entries
with "objectclass=corbaObject". By using the attributes supplied by
the LDAP service provider, the CORBA object factory can quickly
eliminate objects that it need not worry about, and non-CORBA object
factories can quickly eliminate CORBA-related LDAP entries.
- See Also:
(Object obj, Name name, Context nameCtx, Hashtable<?, ?> environment, Attributes attrs)throws ExceptionCreates an object using the location or reference information, and attributes specified.
Special requirements of this object are supplied using
environment. An example of such an environment property is user identity information.
DirectoryManager.getObjectInstance()successively loads in object factories. If it encounters a
DirObjectFactory, it will invoke
DirObjectFactory.getObjectInstance(); otherwise, it invokes
ObjectFactory.getObjectInstance(). It does this until a factory produces a non-null answer.
When an exception is thrown by an object factory, the exception is passed on to the caller of
DirectoryManager.getObjectInstance(). The search for other factories that may produce a non-null answer is halted. An object factory should only throw an exception if it is sure that it is the only intended factory and that no other object factories should be tried. If this factory cannot create an object using the arguments supplied, it should return null.
ObjectFactory, it effectively has two
getObjectInstance()methods, where one differs from the other by the attributes argument. Given a factory that implements
DirectoryManager.getObjectInstance()will only use the method that accepts the attributes argument, while
NamingManager.getObjectInstance()will only use the one that does not accept the attributes argument.
ObjectFactoryfor a description URL context factories and other properties of object factories that apply equally to
environmentparameters are owned by the caller. The implementation will not modify these objects or keep references to them, although it may keep references to clones or copies.
obj- The possibly null object containing location or reference information that can be used in creating an object.
name- The name of this object relative to
nameCtx, or null if no name is specified.
nameCtx- The context relative to which the
nameparameter is specified, or null if
nameis relative to the default initial context.
environment- The possibly null environment that is used in creating the object.
attrs- The possibly null attributes containing some of
attrsmight not necessarily have all of
obj's attributes. If the object factory requires more attributes, it needs to get it, either using
nameCtx. The factory must not modify attrs.
- The object created; null if an object cannot be created.
Exception- If this object factory encountered an exception while attempting to create an object, and no other object factories are to be tried.
- See Also: