- All Known Subinterfaces:
DirStateFactory
The JNDI framework allows for object implementations to
be loaded in dynamically via object factories.
For example, when looking up a printer bound in the name space,
if the print service binds printer names to References, the printer
Reference could be used to create a printer object, so that
the caller of lookup can directly operate on the printer object
after the lookup.
An ObjectFactory is responsible
for creating objects of a specific type. In the above example,
you may have a PrinterObjectFactory for creating
Printer objects.
For the reverse process, when an object is bound into the namespace, JNDI provides state factories. Continuing with the printer example, suppose the printer object is updated and rebound:
ctx.rebind("inky", printer);
ctx uses a state factory
to obtain the state of printer for binding into its namespace.
A state factory for the Printer type object might return
a more compact object for storage in the naming system.
A state factory must implement the StateFactory interface.
In addition, the factory class must be public and must have a
public constructor that accepts no parameters.
Note that in cases where the factory is in a named module then it must be
in a package which is exported by that module to the java.naming
module.
The getStateToBind() method of a state factory may
be invoked multiple times, possibly using different parameters.
The implementation is thread-safe.
StateFactory is intended for use with service providers
that implement only the Context interface.
DirStateFactory is intended for use with service providers
that implement the DirContext interface.
- Since:
- 1.3
- See Also:
-
Method Summary
-
Method Details
-
getStateToBind
Object getStateToBind(Object obj, Name name, Context nameCtx, Hashtable<?, ?> environment) throws NamingExceptionRetrieves the state of an object for binding.NamingManager.getStateToBind()successively loads in state factories and invokes this method on them until one produces a non-null answer.DirectoryManager.getStateToBind()successively loads in state factories. If a factory implementsDirStateFactory, thenDirectoryManagerinvokesDirStateFactory.getStateToBind(); otherwise it invokesStateFactory.getStateToBind().When an exception is thrown by a factory, the exception is passed on to the caller of
NamingManager.getStateToBind()andDirectoryManager.getStateToBind(). The search for other factories that may produce a non-null answer is halted. A factory should only throw an exception if it is sure that it is the only intended factory and that no other factories should be tried. If this factory cannot create an object using the arguments supplied, it should return null.The
nameandnameCtxparameters may optionally be used to specify the name of the object being created. See the description of "Name and Context Parameters" inObjectFactory.getObjectInstance()for details. If a factory usesnameCtxit should synchronize its use against concurrent access, since context implementations are not guaranteed to be thread-safe.The
nameandenvironmentparameters 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.- Parameters:
obj- A non-null object whose state is to be retrieved.name- The name of this object relative tonameCtx, or null if no name is specified.nameCtx- The context relative to which thenameparameter is specified, or null ifnameis relative to the default initial context.environment- The possibly null environment to be used in the creation of the object's state.- Returns:
- The object's state for binding; null if the factory is not returning any changes.
- Throws:
NamingException- if this factory encountered an exception while attempting to get the object's state, and no other factories are to be tried.- See Also:
-