1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
/*
* Copyright (c) OSGi Alliance (2012, 2015). All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.osgi.framework;
import org.osgi.annotation.versioning.ConsumerType;
/**
* A factory for {@link Constants#SCOPE_PROTOTYPE prototype scope} services. The
* factory can provide multiple, customized service objects in the OSGi
* environment.
*
* <p>
* When registering a service, a {@code PrototypeServiceFactory} object can be
* used instead of a service object, so that the bundle developer can create a
* customized service object for each caller that is using the service.
*
* <p>
* When a caller uses a {@link ServiceObjects} to
* {@link ServiceObjects#getService() request} a service object, the framework
* calls the {@link #getService(Bundle, ServiceRegistration) getService} method
* to return a service object customized for the requesting caller. The caller
* can {@link ServiceObjects#ungetService(Object) release} the returned service
* object and the framework will call the
* {@link #ungetService(Bundle, ServiceRegistration, Object) ungetService}
* method with the service object.
*
* <p>
* When a bundle uses the {@link BundleContext#getService(ServiceReference)}
* method to obtain a service object, the framework must act as if the service
* has {@link Constants#SCOPE_BUNDLE bundle scope}. That is, the framework will
* call the {@link #getService(Bundle, ServiceRegistration) getService} method
* to obtain a bundle-scoped service object which will be cached and have a use
* count. See {@link ServiceFactory}.
*
* <p>
* A bundle can use both {@link ServiceObjects} and
* {@link BundleContext#getService(ServiceReference)} to obtain a service object
* for a service. {@link ServiceObjects#getService()} will always return a
* service object provided by a call to
* {@link #getService(Bundle, ServiceRegistration)} and
* {@link BundleContext#getService(ServiceReference)} will always return the
* bundle-scoped service object.
*
* <p>
* {@code PrototypeServiceFactory} objects are only used by the Framework and
* are not made available to other bundles in the OSGi environment. The
* Framework may concurrently call a {@code PrototypeServiceFactory}.
*
* @param <S> Type of Service
* @see BundleContext#getServiceObjects(ServiceReference)
* @see ServiceObjects
* @ThreadSafe
* @since 1.8
* @author $Id$
*/
@ConsumerType
public interface PrototypeServiceFactory<S> extends ServiceFactory<S> {
/**
* Returns a service object for a caller.
*
* <p>
* The Framework invokes this method for each caller requesting a service
* object using {@link ServiceObjects#getService()}. The factory can then
* return a customized service object for the caller.
*
* <p>
* The Framework must check that the returned service object is valid. If
* the returned service object is {@code null} or is not an
* {@code instanceof} all the classes named when the service was registered,
* a framework event of type {@link FrameworkEvent#ERROR} is fired
* containing a service exception of type
* {@link ServiceException#FACTORY_ERROR} and {@code null} is returned to
* the caller. If this method throws an exception, a framework event of type
* {@link FrameworkEvent#ERROR} is fired containing a service exception of
* type {@link ServiceException#FACTORY_EXCEPTION} with the thrown exception
* as the cause and {@code null} is returned to the caller.
*
* @param bundle The bundle requesting the service.
* @param registration The {@code ServiceRegistration} object for the
* requested service.
* @return A service object that <strong>must</strong> be an instance of all
* the classes named when the service was registered.
* @see ServiceObjects#getService()
*/
@Override
public S getService(Bundle bundle, ServiceRegistration<S> registration);
/**
* Releases a service object customized for a caller.
*
* <p>
* The Framework invokes this method when a service has been released by a
* bundle such as by calling {@link ServiceObjects#ungetService(Object)}.
* The service object may then be destroyed.
*
* <p>
* If this method throws an exception, a framework event of type
* {@link FrameworkEvent#ERROR} is fired containing a service exception of
* type {@link ServiceException#FACTORY_EXCEPTION} with the thrown exception
* as the cause.
*
* @param bundle The bundle releasing the service.
* @param registration The {@code ServiceRegistration} object for the
* service being released.
* @param service The service object returned by a previous call to the
* {@link #getService(Bundle, ServiceRegistration) getService}
* method.
* @see ServiceObjects#ungetService(Object)
*/
@Override
public void ungetService(Bundle bundle, ServiceRegistration<S> registration, S service);
}
|
