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src/java.naming/share/classes/javax/naming/spi/DirObjectFactory.java

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  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.naming.spi;
  27 
  28 import java.util.Hashtable;
  29 import javax.naming.*;
  30 import javax.naming.directory.Attributes;
  31 
  32 /**
  33   * This interface represents a factory for creating an object given
  34   * an object and attributes about the object.
  35   *<p>
  36   * The JNDI framework allows for object implementations to
  37   * be loaded in dynamically via <em>object factories</em>. See
  38   * <tt>ObjectFactory</tt> for details.
  39   * <p>
  40   * A <tt>DirObjectFactory</tt> extends <tt>ObjectFactory</tt> by allowing
  41   * an <tt>Attributes</tt> instance
  42   * to be supplied to the <tt>getObjectInstance()</tt> method.
  43   * <tt>DirObjectFactory</tt> implementations are intended to be used by <tt>DirContext</tt>
  44   * service providers. The service provider, in addition reading an
  45   * object from the directory, might already have attributes that
  46   * are useful for the object factory to check to see whether the
  47   * factory is supposed to process the object. For instance, an LDAP-style
  48   * service provider might have read the "objectclass" of the object.
  49   * A CORBA object factory might be interested only in LDAP entries
  50   * with "objectclass=corbaObject". By using the attributes supplied by
  51   * the LDAP service provider, the CORBA object factory can quickly
  52   * eliminate objects that it need not worry about, and non-CORBA object
  53   * factories can quickly eliminate CORBA-related LDAP entries.
  54   *
  55   * @author Rosanna Lee
  56   * @author Scott Seligman
  57   *
  58   * @see NamingManager#getObjectInstance
  59   * @see DirectoryManager#getObjectInstance
  60   * @see ObjectFactory
  61   * @since 1.3
  62   */
  63 
  64 public interface DirObjectFactory extends ObjectFactory {
  65 /**
  66  * Creates an object using the location or reference information, and attributes
  67  * specified.
  68  * <p>
  69  * Special requirements of this object are supplied
  70  * using <code>environment</code>.
  71  * An example of such an environment property is user identity
  72  * information.
  73  *<p>
  74  * <tt>DirectoryManager.getObjectInstance()</tt>
  75  * successively loads in object factories. If it encounters a <tt>DirObjectFactory</tt>,
  76  * it will invoke <tt>DirObjectFactory.getObjectInstance()</tt>;
  77  * otherwise, it invokes
  78  * <tt>ObjectFactory.getObjectInstance()</tt>. It does this until a factory
  79  * produces a non-null answer.
  80  * <p> When an exception
  81  * is thrown by an object factory, the exception is passed on to the caller
  82  * of <tt>DirectoryManager.getObjectInstance()</tt>. The search for other factories
  83  * that may produce a non-null answer is halted.
  84  * An object factory should only throw an exception if it is sure that
  85  * it is the only intended factory and that no other object factories
  86  * should be tried.
  87  * If this factory cannot create an object using the arguments supplied,
  88  * it should return null.
  89   *<p>Since <tt>DirObjectFactory</tt> extends <tt>ObjectFactory</tt>, it
  90   * effectively
  91   * has two <tt>getObjectInstance()</tt> methods, where one differs from the other by
  92   * the attributes argument. Given a factory that implements <tt>DirObjectFactory</tt>,
  93   * <tt>DirectoryManager.getObjectInstance()</tt> will only
  94   * use the method that accepts the attributes argument, while
  95   * <tt>NamingManager.getObjectInstance()</tt> will only use the one that does not accept
  96   * the attributes argument.
  97  *<p>
  98  * See <tt>ObjectFactory</tt> for a description URL context factories and other
  99  * properties of object factories that apply equally to <tt>DirObjectFactory</tt>.
 100  *<p>
 101  * The <tt>name</tt>, <tt>attrs</tt>, and <tt>environment</tt> parameters
 102  * are owned by the caller.
 103  * The implementation will not modify these objects or keep references
 104  * to them, although it may keep references to clones or copies.
 105  *
 106  * @param obj The possibly null object containing location or reference
 107  *              information that can be used in creating an object.
 108  * @param name The name of this object relative to <code>nameCtx</code>,
 109  *              or null if no name is specified.
 110  * @param nameCtx The context relative to which the <code>name</code>
 111  *              parameter is specified, or null if <code>name</code> is
 112  *              relative to the default initial context.
 113  * @param environment The possibly null environment that is used in
 114  *              creating the object.
 115  * @param attrs The possibly null attributes containing some of <tt>obj</tt>'s
 116  * attributes. <tt>attrs</tt> might not necessarily have all of <tt>obj</tt>'s
 117  * attributes. If the object factory requires more attributes, it needs
 118  * to get it, either using <tt>obj</tt>, or <tt>name</tt> and <tt>nameCtx</tt>.
 119  *      The factory must not modify attrs.
 120  * @return The object created; null if an object cannot be created.
 121  * @exception Exception If this object factory encountered an exception
 122  * while attempting to create an object, and no other object factories are
 123  * to be tried.
 124  *
 125  * @see DirectoryManager#getObjectInstance
 126  * @see NamingManager#getURLContext
 127  */
 128     public Object getObjectInstance(Object obj, Name name, Context nameCtx,
 129                                     Hashtable<?,?> environment,
 130                                     Attributes attrs)
 131         throws Exception;
 132 }


  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.naming.spi;
  27 
  28 import java.util.Hashtable;
  29 import javax.naming.*;
  30 import javax.naming.directory.Attributes;
  31 
  32 /**
  33   * This interface represents a factory for creating an object given
  34   * an object and attributes about the object.
  35   *<p>
  36   * The JNDI framework allows for object implementations to
  37   * be loaded in dynamically via <em>object factories</em>. See
  38   * {@code ObjectFactory} for details.
  39   * <p>
  40   * A {@code DirObjectFactory} extends {@code ObjectFactory} by allowing
  41   * an {@code Attributes} instance
  42   * to be supplied to the {@code getObjectInstance()} method.
  43   * {@code DirObjectFactory} implementations are intended to be used by {@code DirContext}
  44   * service providers. The service provider, in addition reading an
  45   * object from the directory, might already have attributes that
  46   * are useful for the object factory to check to see whether the
  47   * factory is supposed to process the object. For instance, an LDAP-style
  48   * service provider might have read the "objectclass" of the object.
  49   * A CORBA object factory might be interested only in LDAP entries
  50   * with "objectclass=corbaObject". By using the attributes supplied by
  51   * the LDAP service provider, the CORBA object factory can quickly
  52   * eliminate objects that it need not worry about, and non-CORBA object
  53   * factories can quickly eliminate CORBA-related LDAP entries.
  54   *
  55   * @author Rosanna Lee
  56   * @author Scott Seligman
  57   *
  58   * @see NamingManager#getObjectInstance
  59   * @see DirectoryManager#getObjectInstance
  60   * @see ObjectFactory
  61   * @since 1.3
  62   */
  63 
  64 public interface DirObjectFactory extends ObjectFactory {
  65 /**
  66  * Creates an object using the location or reference information, and attributes
  67  * specified.
  68  * <p>
  69  * Special requirements of this object are supplied
  70  * using <code>environment</code>.
  71  * An example of such an environment property is user identity
  72  * information.
  73  *<p>
  74  * {@code DirectoryManager.getObjectInstance()}
  75  * successively loads in object factories. If it encounters a {@code DirObjectFactory},
  76  * it will invoke {@code DirObjectFactory.getObjectInstance()};
  77  * otherwise, it invokes
  78  * {@code ObjectFactory.getObjectInstance()}. It does this until a factory
  79  * produces a non-null answer.
  80  * <p> When an exception
  81  * is thrown by an object factory, the exception is passed on to the caller
  82  * of {@code DirectoryManager.getObjectInstance()}. The search for other factories
  83  * that may produce a non-null answer is halted.
  84  * An object factory should only throw an exception if it is sure that
  85  * it is the only intended factory and that no other object factories
  86  * should be tried.
  87  * If this factory cannot create an object using the arguments supplied,
  88  * it should return null.
  89   *<p>Since {@code DirObjectFactory} extends {@code ObjectFactory}, it
  90   * effectively
  91   * has two {@code getObjectInstance()} methods, where one differs from the other by
  92   * the attributes argument. Given a factory that implements {@code DirObjectFactory},
  93   * {@code DirectoryManager.getObjectInstance()} will only
  94   * use the method that accepts the attributes argument, while
  95   * {@code NamingManager.getObjectInstance()} will only use the one that does not accept
  96   * the attributes argument.
  97  *<p>
  98  * See {@code ObjectFactory} for a description URL context factories and other
  99  * properties of object factories that apply equally to {@code DirObjectFactory}.
 100  *<p>
 101  * The {@code name}, {@code attrs}, and {@code environment} parameters
 102  * are owned by the caller.
 103  * The implementation will not modify these objects or keep references
 104  * to them, although it may keep references to clones or copies.
 105  *
 106  * @param obj The possibly null object containing location or reference
 107  *              information that can be used in creating an object.
 108  * @param name The name of this object relative to <code>nameCtx</code>,
 109  *              or null if no name is specified.
 110  * @param nameCtx The context relative to which the <code>name</code>
 111  *              parameter is specified, or null if <code>name</code> is
 112  *              relative to the default initial context.
 113  * @param environment The possibly null environment that is used in
 114  *              creating the object.
 115  * @param attrs The possibly null attributes containing some of {@code obj}'s
 116  * attributes. {@code attrs} might not necessarily have all of {@code obj}'s
 117  * attributes. If the object factory requires more attributes, it needs
 118  * to get it, either using {@code obj}, or {@code name} and {@code nameCtx}.
 119  *      The factory must not modify attrs.
 120  * @return The object created; null if an object cannot be created.
 121  * @exception Exception If this object factory encountered an exception
 122  * while attempting to create an object, and no other object factories are
 123  * to be tried.
 124  *
 125  * @see DirectoryManager#getObjectInstance
 126  * @see NamingManager#getURLContext
 127  */
 128     public Object getObjectInstance(Object obj, Name name, Context nameCtx,
 129                                     Hashtable<?,?> environment,
 130                                     Attributes attrs)
 131         throws Exception;
 132 }
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