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package javax.naming.spi;
import java.util.Hashtable;
import javax.naming.*;
import javax.naming.directory.Attributes;
This interface represents a factory for creating an object given
an object and attributes about the object.
The JNDI framework allows for object implementations to
be loaded in dynamically via object factories. See ObjectFactory for details.
A DirObjectFactory extends ObjectFactory by allowing an Attributes instance to be supplied to the getObjectInstance() method. DirObjectFactory implementations are intended to be used by DirContext 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.
Author: Rosanna Lee, Scott Seligman See Also: Since: 1.3
/**
* This interface represents a factory for creating an object given
* an object and attributes about the object.
*<p>
* The JNDI framework allows for object implementations to
* be loaded in dynamically via <em>object factories</em>. See
* {@code ObjectFactory} for details.
* <p>
* A {@code DirObjectFactory} extends {@code ObjectFactory} by allowing
* an {@code Attributes} instance
* to be supplied to the {@code getObjectInstance()} method.
* {@code DirObjectFactory} implementations are intended to be used by {@code DirContext}
* 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.
*
* @author Rosanna Lee
* @author Scott Seligman
*
* @see NamingManager#getObjectInstance
* @see DirectoryManager#getObjectInstance
* @see ObjectFactory
* @since 1.3
*/
public interface DirObjectFactory extends ObjectFactory {
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.
Params: - 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
name
parameter is specified, or null if name is
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
obj's attributes. attrs might not necessarily have all of obj's attributes. If the object factory requires more attributes, it needs to get it, either using obj, or name and nameCtx. The factory must not modify attrs.
Throws: - 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: Returns: The object created; null if an object cannot be created.
/**
* Creates an object using the location or reference information, and attributes
* specified.
* <p>
* Special requirements of this object are supplied
* using <code>environment</code>.
* An example of such an environment property is user identity
* information.
*<p>
* {@code DirectoryManager.getObjectInstance()}
* successively loads in object factories. If it encounters a {@code DirObjectFactory},
* it will invoke {@code DirObjectFactory.getObjectInstance()};
* otherwise, it invokes
* {@code ObjectFactory.getObjectInstance()}. It does this until a factory
* produces a non-null answer.
* <p> When an exception
* is thrown by an object factory, the exception is passed on to the caller
* of {@code 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.
*<p>Since {@code DirObjectFactory} extends {@code ObjectFactory}, it
* effectively
* has two {@code getObjectInstance()} methods, where one differs from the other by
* the attributes argument. Given a factory that implements {@code DirObjectFactory},
* {@code DirectoryManager.getObjectInstance()} will only
* use the method that accepts the attributes argument, while
* {@code NamingManager.getObjectInstance()} will only use the one that does not accept
* the attributes argument.
*<p>
* See {@code ObjectFactory} for a description URL context factories and other
* properties of object factories that apply equally to {@code DirObjectFactory}.
*<p>
* The {@code name}, {@code attrs}, and {@code 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.
*
* @param obj The possibly null object containing location or reference
* information that can be used in creating an object.
* @param name The name of this object relative to <code>nameCtx</code>,
* or null if no name is specified.
* @param nameCtx The context relative to which the <code>name</code>
* parameter is specified, or null if <code>name</code> is
* relative to the default initial context.
* @param environment The possibly null environment that is used in
* creating the object.
* @param attrs The possibly null attributes containing some of {@code obj}'s
* attributes. {@code attrs} might not necessarily have all of {@code obj}'s
* attributes. If the object factory requires more attributes, it needs
* to get it, either using {@code obj}, or {@code name} and {@code nameCtx}.
* The factory must not modify attrs.
* @return The object created; null if an object cannot be created.
* @exception Exception If this object factory encountered an exception
* while attempting to create an object, and no other object factories are
* to be tried.
*
* @see DirectoryManager#getObjectInstance
* @see NamingManager#getURLContext
*/
public Object getObjectInstance(Object obj, Name name, Context nameCtx,
Hashtable<?,?> environment,
Attributes attrs)
throws Exception;
}