1 /**
2 * This file Copyright (c) 2010-2011 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.objectfactory;
35
36 /**
37 * Static access utility for the currently set {@link ComponentProvider}. The current {@link ComponentProvider} is set
38 * during start-up and there should be little reason to change it at runtime.
39 *
40 * Since Magnolia 4.5, you are encouraged to use IoC, only in rare cases should you need to directly use this class.
41 *
42 * @version $Id$
43 * @see ComponentProvider
44 */
45 public class Components {
46
47 private static volatile ComponentProvider componentProvider = new NullComponentProvider();
48
49 /**
50 * Sets the current {@link ComponentProvider}.
51 */
52 public static void setComponentProvider(ComponentProvider provider) {
53 componentProvider = provider;
54 }
55
56 /**
57 * Returns the currently set {@link ComponentProvider}.
58 */
59 public static ComponentProvider getComponentProvider() {
60 return componentProvider;
61 }
62
63 /**
64 * Returns a component from the currently set {@link ComponentProvider}.
65 *
66 * @see ComponentProvider#getComponent(Class)
67 * @deprecated since 4.5, use IoC to inject the component or use #getComponent(Class).
68 */
69 public static <T> T getSingleton(Class<T> type) {
70 return getComponent(type);
71 }
72
73 public static <T> T newInstance(Class<T> type, Object... parameters) {
74 return getComponentProvider().newInstance(type, parameters);
75 }
76
77 /**
78 * Returns a component from the currently set {@link ComponentProvider}. Consider using IoC to inject the component instead.
79 */
80 public static <T> T getComponent(Class<T> type) {
81 return getComponentProvider().getComponent(type);
82 }
83
84 private static class NullComponentProvider implements ComponentProvider {
85
86 @Override
87 public <C> Class<? extends C> getImplementation(Class<C> type) throws ClassNotFoundException {
88 throw new IllegalStateException("No ComponentProvider has been set yet, something must have gone terribly wrong at startup.");
89 }
90
91 @Override
92 public <T> T getComponent(Class<T> type) {
93 throw new IllegalStateException("No ComponentProvider has been set yet, something must have gone terribly wrong at startup.");
94 }
95
96 @Override
97 public <T> T getSingleton(Class<T> type) {
98 throw new IllegalStateException("No ComponentProvider has been set yet, something must have gone terribly wrong at startup.");
99 }
100
101 public <T> T newInstance(Class<T> type) {
102 throw new IllegalStateException("No ComponentProvider has been set yet, something must have gone terribly wrong at startup.");
103 }
104
105 @Override
106 public <T> T newInstance(Class<T> type, Object... parameters) {
107 throw new IllegalStateException("No ComponentProvider has been set yet, something must have gone terribly wrong at startup.");
108 }
109
110 @Override
111 public <T> T newInstanceWithParameterResolvers(Class<T> type, ParameterResolver... parameters) {
112 throw new IllegalStateException("No ComponentProvider has been set yet, something must have gone terribly wrong at startup.");
113 }
114
115 @Override
116 public ComponentProvider getParent() {
117 throw new IllegalStateException("No ComponentProvider has been set yet, something must have gone terribly wrong at startup.");
118 }
119
120 }
121 }