1 /* Copyright (c) 2008 Sascha Kohlmann
2 *
3 * This program is free software: you can redistribute it and/or modify
4 * it under the terms of the GNU Affero General Public License as published by
5 * the Free Software Foundation, either version 3 of the License, or
6 * (at your option) any later version.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU Affero General Public License for more details.
12 *
13 * You should have received a copy of the GNU Affero General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16 package net.sf.eos.entity;
17
18 import static net.sf.eos.config.ConfigurationKey.Type.CLASSNAME;
19
20 import org.apache.commons.logging.Log;
21 import org.apache.commons.logging.LogFactory;
22
23 import java.util.Locale;
24
25 import net.sf.eos.EosException;
26 import net.sf.eos.config.Configuration;
27 import net.sf.eos.config.ConfigurationKey;
28 import net.sf.eos.config.Configured;
29 import net.sf.eos.config.FactoryMethod;
30
31 /**
32 * The common name resolver maps an ID of an entity to the common name of
33 * the entity.
34 * @author Sascha Kohlmann
35 */
36 public abstract class CommonNameResolver extends Configured {
37
38 /** For logging. */
39 private static final Log LOG =
40 LogFactory.getLog(CommonNameResolver.class.getName());
41
42 /** The configuration key name for the classname of the factory.
43 * @see #newInstance(Configuration) */
44 @SuppressWarnings("nls")
45 @ConfigurationKey(type=CLASSNAME,
46 description="Resolver remaps an entity ID to a "
47 + "common name (human readable).")
48 public final static String COMMON_NAME_RESOLVER_IMPL_CONFIG_NAME =
49 "net.sf.eos.entity.CommonNameResolver.impl";
50
51 /**
52 * Creates a new instance of a of the recognizer. If the
53 * {@code Configuration} contains a key
54 * {@link #COMMON_NAME_RESOLVER_IMPL_CONFIG_NAME}
55 * a new instance of the classname in the value will instantiate.
56 * @param config the configuration
57 * @return a new instance
58 * @throws EosException if it is not possible to instantiate an instance
59 */
60 @FactoryMethod(key=COMMON_NAME_RESOLVER_IMPL_CONFIG_NAME)
61 public final static CommonNameResolver newInstance(final Configuration config)
62 throws EosException {
63
64 final Thread t = Thread.currentThread();
65 ClassLoader classLoader = t.getContextClassLoader();
66 if (classLoader == null) {
67 classLoader =
68 AbstractDictionaryBasedEntityRecognizer.class.getClassLoader();
69 }
70
71 final String clazzName = config.get(COMMON_NAME_RESOLVER_IMPL_CONFIG_NAME);
72
73 try {
74 final Class<? extends CommonNameResolver> clazz =
75 (Class<? extends CommonNameResolver>)
76 Class.forName(clazzName, true, classLoader);
77 try {
78
79 final CommonNameResolver instance = clazz.newInstance();
80 if (LOG.isDebugEnabled()) {
81 LOG.debug("CommonNameResolver instance: "
82 + instance.getClass().getName());
83 }
84 instance.configure(config);
85 return instance;
86
87 } catch (final InstantiationException e) {
88 throw new EosException(e);
89 } catch (final IllegalAccessException e) {
90 throw new EosException(e);
91 }
92 } catch (final ClassNotFoundException e) {
93 throw new EosException(e);
94 }
95 }
96
97 /**
98 * Resolves the common entity name for the default locale of the platform.
99 * @param id the ID of the entity
100 * @return a common name or {@code null} if the implementation is
101 * unable to resolve a common name.
102 * @throws EosException if an error occurs
103 */
104 public String resolveCommonName(final String id) throws EosException {
105 final Locale locale = Locale.getDefault();
106 return resolveCommonName(id, locale);
107 }
108
109 /**
110 * Resolves the common entity name for the given locale if available.
111 * @param id the ID of the entity
112 * @param locale to get the right language of the common name.
113 * @return a common name or {@code null} if the implementation is
114 * unable to resolve a common name.
115 * @throws EosException if an error occurs
116 */
117 public abstract String resolveCommonName(final String id,
118 final Locale locale) throws EosException;
119 }