001 /*
002 * Copyright 1998-2004 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.beans.beancontext;
027
028 import java.util.Iterator;
029
030 /**
031 * <p>
032 * One of the primary functions of a BeanContext is to act a as rendezvous
033 * between JavaBeans, and BeanContextServiceProviders.
034 * </p>
035 * <p>
036 * A JavaBean nested within a BeanContext, may ask that BeanContext to
037 * provide an instance of a "service", based upon a reference to a Java
038 * Class object that represents that service.
039 * </p>
040 * <p>
041 * If such a service has been registered with the context, or one of its
042 * nesting context's, in the case where a context delegate to its context
043 * to satisfy a service request, then the BeanContextServiceProvider associated with
044 * the service is asked to provide an instance of that service.
045 * </p>
046 * <p>
047 * The ServcieProvider may always return the same instance, or it may
048 * construct a new instance for each request.
049 * </p>
050 */
051
052 public interface BeanContextServiceProvider {
053
054 /**
055 * Invoked by <code>BeanContextServices</code>, this method
056 * requests an instance of a
057 * service from this <code>BeanContextServiceProvider</code>.
058 *
059 * @param bcs The <code>BeanContextServices</code> associated with this
060 * particular request. This parameter enables the
061 * <code>BeanContextServiceProvider</code> to distinguish service
062 * requests from multiple sources.
063 *
064 * @param requestor The object requesting the service
065 *
066 * @param serviceClass The service requested
067 *
068 * @param serviceSelector the service dependent parameter
069 * for a particular service, or <code>null</code> if not applicable.
070 *
071 * @return a reference to the requested service
072 */
073 Object getService(BeanContextServices bcs, Object requestor,
074 Class serviceClass, Object serviceSelector);
075
076 /**
077 * Invoked by <code>BeanContextServices</code>,
078 * this method releases a nested <code>BeanContextChild</code>'s
079 * (or any arbitrary object associated with a
080 * <code>BeanContextChild</code>) reference to the specified service.
081 *
082 * @param bcs the <code>BeanContextServices</code> associated with this
083 * particular release request
084 *
085 * @param requestor the object requesting the service to be released
086 *
087 * @param service the service that is to be released
088 */
089 public void releaseService(BeanContextServices bcs,
090 Object requestor, Object service);
091
092 /**
093 * Invoked by <code>BeanContextServices</code>, this method
094 * gets the current service selectors for the specified service.
095 * A service selector is a service specific parameter,
096 * typical examples of which could include: a
097 * parameter to a constructor for the service implementation class,
098 * a value for a particular service's property, or a key into a
099 * map of existing implementations.
100 *
101 * @param bcs the <code>BeanContextServices</code> for this request
102 * @param serviceClass the specified service
103 * @return the current service selectors for the specified serviceClass
104 */
105 Iterator getCurrentServiceSelectors(BeanContextServices bcs,
106 Class serviceClass);
107 }
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