Creates 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.
Since DirObjectFactory extends ObjectFactory, it
effectively
has two getObjectInstance() methods, where one differs from the other by
the attributes argument. Given a factory that implements DirObjectFactory,
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.
See ObjectFactory for a description URL context factories and other
properties of object factories that apply equally to DirObjectFactory.
The name, attrs, and environment parameters
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.
