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1
15 package org.apache.hivemind.impl;
16
17 import java.lang.reflect.Constructor  ;
18 import java.util.HashMap ;
19 import java.util.Iterator ;
20 import java.util.List ;
21 import java.util.Map ;
22
23 import org.apache.commons.logging.Log;
24 import org.apache.commons.logging.LogFactory;
25 import org.apache.hivemind.ApplicationRuntimeException;
26 import org.apache.hivemind.ErrorHandler;
27 import org.apache.hivemind.Location;
28 import org.apache.hivemind.internal.RegistryInfrastructure;
29 import org.apache.hivemind.schema.Translator;
30 import org.apache.hivemind.schema.rules.ClassTranslator;
31 import org.apache.hivemind.schema.rules.InstanceTranslator;
32 import org.apache.hivemind.schema.rules.ServiceTranslator;
33 import org.apache.hivemind.schema.rules.SmartTranslator;
34
35
40 public class TranslatorManager
41 {
42 static final Log LOG = LogFactory.getLog(TranslatorManager.class);
43
44 public static final String TRANSLATORS_CONFIGURATION_ID = "hivemind.Translators";
45
46 private ErrorHandler _errorHandler;
47
48 private RegistryInfrastructure _registry;
49
50
55 private Map _translatorClasses = new HashMap ();
56
57 private Map _translatorsCache = new HashMap ();
58
59 private boolean _translatorsLoaded;
60
61 public TranslatorManager(RegistryInfrastructure registry, ErrorHandler errorHandler)
62 {
63 _registry = registry;
64 _errorHandler = errorHandler;
65
66
69 _translatorsCache.put("class", new ClassTranslator());
70 _translatorsCache.put("service", new ServiceTranslator());
71 _translatorsCache.put("smart", new SmartTranslator());
72 _translatorsCache.put("instance", new InstanceTranslator());
73
74
77 _translatorClasses.put("smart", SmartTranslator.class);
78
79 }
80
81 public synchronized Translator getTranslator(String constructor)
82 {
83
85 if (!_translatorsLoaded && !_translatorsCache.containsKey(constructor))
86 loadTranslators();
87
88 Translator result = (Translator) _translatorsCache.get(constructor);
89
90 if (result == null)
91 {
92 result = constructTranslator(constructor);
93 _translatorsCache.put(constructor, result);
94 }
95
96 return result;
97 }
98
99 private Translator constructTranslator(String constructor)
100 {
101 String name = constructor;
102 String initializer = null;
103
104 int commax = constructor.indexOf(',');
105
106 if (commax > 0)
107 {
108 name = constructor.substring(0, commax);
109 initializer = constructor.substring(commax + 1);
110 }
111
112 Class translatorClass = findTranslatorClass(name);
113
114
116 return createTranslator(translatorClass, initializer);
117 }
118
119 private Translator createTranslator(Class translatorClass, String initializer)
120 {
121 try
122 {
123
124 if (initializer == null)
125 return (Translator) translatorClass.newInstance();
126
127 Constructor c = translatorClass.getConstructor(new Class []
128 { String .class });
129
130 return (Translator) c.newInstance(new Object []
131 { initializer });
132 }
133 catch (Exception ex)
134 {
135 throw new ApplicationRuntimeException(ImplMessages.translatorInstantiationFailure(
136 translatorClass,
137 ex), ex);
138 }
139 }
140
141 private Class findTranslatorClass(String translatorName)
142 {
143 Class result = (Class ) _translatorClasses.get(translatorName);
144
145 if (result == null)
146 throw new ApplicationRuntimeException(ImplMessages.unknownTranslatorName(
147 translatorName,
148 TRANSLATORS_CONFIGURATION_ID));
149
150 return result;
151 }
152
153 private void loadTranslators()
154 {
155
157 _translatorsLoaded = true;
158
159 List contributions = _registry.getConfiguration(TRANSLATORS_CONFIGURATION_ID, null);
160
161 Map locations = new HashMap ();
162 locations.put("class", null);
163
164 Iterator i = contributions.iterator();
165 while (i.hasNext())
166 {
167 TranslatorContribution c = (TranslatorContribution) i.next();
168
169 String name = c.getName();
170 Location oldLocation = (Location) locations.get(name);
171
172 if (oldLocation != null)
173 {
174 _errorHandler.error(LOG, ImplMessages.duplicateTranslatorName(name, oldLocation), c
175 .getLocation(), null);
176
177 continue;
178 }
179
180 locations.put(name, c.getLocation());
181
182 Translator t = c.getTranslator();
183
184 if (t != null)
185 {
186 _translatorsCache.put(name, t);
187 continue;
188 }
189
190 Class tClass = c.getTranslatorClass();
191
192 if (tClass == null)
193 {
194 _errorHandler.error(
195 LOG,
196 ImplMessages.incompleteTranslator(c),
197 c.getLocation(),
198 null);
199 continue;
200 }
201
202 _translatorClasses.put(name, tClass);
203 }
204
205 }
206
207 } |
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