1 /*
2 * #%L
3 * settings4j
4 * ===============================================================
5 * Copyright (C) 2008 - 2015 Brabenetz Harald, Austria
6 * ===============================================================
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * #L%
19 */
20 package org.settings4j.settings;
21
22 import java.net.URL;
23
24 import javax.xml.parsers.FactoryConfigurationError;
25
26 import org.settings4j.Settings4jInstance;
27 import org.settings4j.Settings4jRepository;
28 import org.settings4j.config.DOMConfigurator;
29 import org.settings4j.contentresolver.ClasspathContentResolver;
30
31 /**
32 * manage the {@link Settings4jRepository} which is used to store the configuration from the settings4j.xml.
33 *
34 * @author Harald.Brabenetz
35 */
36 public final class SettingsManager {
37
38 /** General Logger for this Class. */
39 private static final org.slf4j.Logger LOG = org.slf4j.LoggerFactory.getLogger(SettingsManager.class);
40
41 /**
42 * The Classpath-Location of the settings4j.xml who i readed by default. <br>
43 * settings4j.xml
44 */
45 public static final String DEFAULT_XML_CONFIGURATION_FILE = "settings4j.xml";
46
47 /**
48 * The fallback settings4j.xml who is used if not settings4j.xml where found. <br>
49 * org/settings4j/config/defaultsettings4j.xml
50 */
51 public static final String DEFAULT_FALLBACK_CONFIGURATION_FILE = "org/settings4j/config/defaultsettings4j.xml";
52
53 /**
54 * The internal default Settings4j Repository where all {@link org.settings4j.Settings4j} are stored.
55 */
56 private static Settings4jRepository settingsRepository = new DefaultSettingsRepository();
57 static {
58 initializeRepository(SettingsManager.DEFAULT_XML_CONFIGURATION_FILE);
59 initializeRepositoryIfNecessary(); // default fallback if connectors are empty
60 }
61
62 /** Hide Constructor, Utility Pattern. */
63 private SettingsManager() {
64 super();
65 }
66
67 /**
68 * The internal default Settings4j Repository where all {@link org.settings4j.Settings4j} are stored.
69 *
70 * @return The Settings4j Repository, Returns NEVER null.
71 */
72 public static Settings4jRepository getSettingsRepository() {
73 return settingsRepository;
74 }
75
76 /**
77 * Retrieve the appropriate {@link org.settings4j.Settings4j} instance.
78 *
79 * @return the appropriate {@link org.settings4j.Settings4j} instance.
80 */
81 public static Settings4jInstance getSettings() {
82 initializeRepositoryIfNecessary();
83 // Delegate the actual manufacturing of the settings to the settings repository.
84 return getSettingsRepository().getSettings();
85 }
86
87 /**
88 * Check if the repository must be configured with the defaul fallback settings4j.xml.
89 */
90 private static void initializeRepositoryIfNecessary() {
91 if (getSettingsRepository().getConnectorCount() == 0) {
92 // No connectors in hierarchy, add default-configuration.
93 initializeRepository(SettingsManager.DEFAULT_FALLBACK_CONFIGURATION_FILE);
94 }
95 }
96
97 private static void initializeRepository(final String configurationFile) throws FactoryConfigurationError {
98 LOG.debug("Using URL [{}] for automatic settings4j configuration.", configurationFile);
99
100 final URL url = ClasspathContentResolver.getResource(configurationFile);
101
102 // If we have a non-null url, then delegate the rest of the
103 // configuration to the DOMConfigurator.configure method.
104 if (url != null) {
105 LOG.info("The settings4j will be configured with the config: {}", url);
106 try {
107 DOMConfigurator.configure(url, getSettingsRepository());
108 } catch (final NoClassDefFoundError e) {
109 LOG.warn("Error during initialization {}", configurationFile, e);
110 }
111 } else {
112 if (SettingsManager.DEFAULT_FALLBACK_CONFIGURATION_FILE.equals(configurationFile)) {
113 LOG.error("Could not find resource: [{}].", configurationFile);
114 } else {
115 LOG.debug("Could not find resource: [{}]. Use default fallback.", configurationFile);
116 }
117 }
118 }
119 }