1 /*
2 * Copyright 1998-2004 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package java.beans.beancontext;
27
28 import java.util.Iterator;
29
30 /**
31 * <p>
32 * One of the primary functions of a BeanContext is to act a as rendezvous
33 * between JavaBeans, and BeanContextServiceProviders.
34 * </p>
35 * <p>
36 * A JavaBean nested within a BeanContext, may ask that BeanContext to
37 * provide an instance of a "service", based upon a reference to a Java
38 * Class object that represents that service.
39 * </p>
40 * <p>
41 * If such a service has been registered with the context, or one of its
42 * nesting context's, in the case where a context delegate to its context
43 * to satisfy a service request, then the BeanContextServiceProvider associated with
44 * the service is asked to provide an instance of that service.
45 * </p>
46 * <p>
47 * The ServcieProvider may always return the same instance, or it may
48 * construct a new instance for each request.
49 * </p>
50 */
51
52 public interface BeanContextServiceProvider {
53
54 /**
55 * Invoked by <code>BeanContextServices</code>, this method
56 * requests an instance of a
57 * service from this <code>BeanContextServiceProvider</code>.
58 *
59 * @param bcs The <code>BeanContextServices</code> associated with this
60 * particular request. This parameter enables the
61 * <code>BeanContextServiceProvider</code> to distinguish service
62 * requests from multiple sources.
63 *
64 * @param requestor The object requesting the service
65 *
66 * @param serviceClass The service requested
67 *
68 * @param serviceSelector the service dependent parameter
69 * for a particular service, or <code>null</code> if not applicable.
70 *
71 * @return a reference to the requested service
72 */
73 Object getService(BeanContextServices bcs, Object requestor, Class serviceClass, Object serviceSelector);
74
75 /**
76 * Invoked by <code>BeanContextServices</code>,
77 * this method releases a nested <code>BeanContextChild</code>'s
78 * (or any arbitrary object associated with a
79 * <code>BeanContextChild</code>) reference to the specified service.
80 *
81 * @param bcs the <code>BeanContextServices</code> associated with this
82 * particular release request
83 *
84 * @param requestor the object requesting the service to be released
85 *
86 * @param service the service that is to be released
87 */
88 public void releaseService(BeanContextServices bcs, Object requestor, Object service);
89
90 /**
91 * Invoked by <code>BeanContextServices</code>, this method
92 * gets the current service selectors for the specified service.
93 * A service selector is a service specific parameter,
94 * typical examples of which could include: a
95 * parameter to a constructor for the service implementation class,
96 * a value for a particular service's property, or a key into a
97 * map of existing implementations.
98 *
99 * @param bcs the <code>BeanContextServices</code> for this request
100 * @param serviceClass the specified service
101 * @return the current service selectors for the specified serviceClass
102 */
103 Iterator getCurrentServiceSelectors(BeanContextServices bcs, Class serviceClass);
104 }
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