| /* |
| * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.naming.spi; |
| |
| import java.util.Hashtable; |
| |
| import javax.naming.*; |
| |
| /** |
| * This interface represents a factory for creating an object. |
| *<p> |
| * The JNDI framework allows for object implementations to |
| * be loaded in dynamically via <em>object factories</em>. |
| * 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. |
| * <p>An {@code ObjectFactory} is responsible |
| * for creating objects of a specific type. In the above example, |
| * you may have a PrinterObjectFactory for creating Printer objects. |
| *<p> |
| * An object factory must implement the {@code ObjectFactory} 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 {@code java.naming} |
| * module. |
| *<p> |
| * The {@code getObjectInstance()} method of an object factory may |
| * be invoked multiple times, possibly using different parameters. |
| * The implementation is thread-safe. |
| *<p> |
| * The mention of URL in the documentation for this class refers to |
| * a URL string as defined by RFC 1738 and its related RFCs. It is |
| * any string that conforms to the syntax described therein, and |
| * may not always have corresponding support in the java.net.URL |
| * class or Web browsers. |
| * |
| * @author Rosanna Lee |
| * @author Scott Seligman |
| * |
| * @see NamingManager#getObjectInstance |
| * @see NamingManager#getURLContext |
| * @see ObjectFactoryBuilder |
| * @see StateFactory |
| * @since 1.3 |
| */ |
| |
| public interface ObjectFactory { |
| /** |
| * Creates an object using the location or reference information |
| * specified. |
| * <p> |
| * Special requirements of this object are supplied |
| * using {@code environment}. |
| * An example of such an environment property is user identity |
| * information. |
| *<p> |
| * {@code NamingManager.getObjectInstance()} |
| * successively loads in object factories and invokes this method |
| * on them until one produces a non-null answer. When an exception |
| * is thrown by an object factory, the exception is passed on to the caller |
| * of {@code NamingManager.getObjectInstance()} |
| * (and no search is made for other factories |
| * that may produce a non-null answer). |
| * 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> |
| * A <em>URL context factory</em> is a special ObjectFactory that |
| * creates contexts for resolving URLs or objects whose locations |
| * are specified by URLs. The {@code getObjectInstance()} method |
| * of a URL context factory will obey the following rules. |
| * <ol> |
| * <li>If {@code obj} is null, create a context for resolving URLs of the |
| * scheme associated with this factory. The resulting context is not tied |
| * to a specific URL: it is able to handle arbitrary URLs with this factory's |
| * scheme id. For example, invoking {@code getObjectInstance()} with |
| * {@code obj} set to null on an LDAP URL context factory would return a |
| * context that can resolve LDAP URLs |
| * such as "ldap://ldap.wiz.com/o=wiz,c=us" and |
| * "ldap://ldap.umich.edu/o=umich,c=us". |
| * <li> |
| * If {@code obj} is a URL string, create an object (typically a context) |
| * identified by the URL. For example, suppose this is an LDAP URL context |
| * factory. If {@code obj} is "ldap://ldap.wiz.com/o=wiz,c=us", |
| * getObjectInstance() would return the context named by the distinguished |
| * name "o=wiz, c=us" at the LDAP server ldap.wiz.com. This context can |
| * then be used to resolve LDAP names (such as "cn=George") |
| * relative to that context. |
| * <li> |
| * If {@code obj} is an array of URL strings, the assumption is that the |
| * URLs are equivalent in terms of the context to which they refer. |
| * Verification of whether the URLs are, or need to be, equivalent is up |
| * to the context factory. The order of the URLs in the array is |
| * not significant. |
| * The object returned by getObjectInstance() is like that of the single |
| * URL case. It is the object named by the URLs. |
| * <li> |
| * If {@code obj} is of any other type, the behavior of |
| * {@code getObjectInstance()} is determined by the context factory |
| * implementation. |
| * </ol> |
| * |
| * <p> |
| * The {@code name} 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. |
| * |
| * <p> |
| * <b>Name and Context Parameters.</b> |
| * <a id=NAMECTX></a> |
| * |
| * The {@code name} and {@code nameCtx} parameters may |
| * optionally be used to specify the name of the object being created. |
| * {@code name} is the name of the object, relative to context |
| * {@code nameCtx}. |
| * If there are several possible contexts from which the object |
| * could be named -- as will often be the case -- it is up to |
| * the caller to select one. A good rule of thumb is to select the |
| * "deepest" context available. |
| * If {@code nameCtx} is null, {@code name} is relative |
| * to the default initial context. If no name is being specified, the |
| * {@code name} parameter should be null. |
| * If a factory uses {@code nameCtx} it should synchronize its use |
| * against concurrent access, since context implementations are not |
| * guaranteed to be thread-safe. |
| * |
| * @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}, |
| * or null if no name is specified. |
| * @param nameCtx The context relative to which the {@code name} |
| * parameter is specified, or null if {@code name} is |
| * relative to the default initial context. |
| * @param environment The possibly null environment that is used in |
| * creating the object. |
| * @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 NamingManager#getObjectInstance |
| * @see NamingManager#getURLContext |
| */ |
| public Object getObjectInstance(Object obj, Name name, Context nameCtx, |
| Hashtable<?,?> environment) |
| throws Exception; |
| } |