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1
15 package org.apache.hivemind.service.impl;
16
17 import java.lang.reflect.Constructor  ;
18 import java.lang.reflect.InvocationTargetException ;
19 import java.lang.reflect.Method ;
20 import java.lang.reflect.Modifier ;
21 import java.util.ArrayList ;
22 import java.util.Collection ;
23 import java.util.Collections ;
24 import java.util.Comparator ;
25 import java.util.HashSet ;
26 import java.util.Iterator ;
27 import java.util.List ;
28 import java.util.Set ;
29
30 import org.apache.commons.logging.Log;
31 import org.apache.hivemind.ApplicationRuntimeException;
32 import org.apache.hivemind.HiveMind;
33 import org.apache.hivemind.Location;
34 import org.apache.hivemind.ServiceImplementationFactoryParameters;
35 import org.apache.hivemind.internal.Module;
36 import org.apache.hivemind.service.Autowiring;
37 import org.apache.hivemind.service.AutowiringStrategy;
38 import org.apache.hivemind.service.EventLinker;
39 import org.apache.hivemind.util.ConstructorUtils;
40 import org.apache.hivemind.util.PropertyUtils;
41
42
48 public class BuilderFactoryLogic
49 {
50
51 private ServiceImplementationFactoryParameters _factoryParameters;
52
53 private String _serviceId;
54
55 private BuilderParameter _parameter;
56
57 private Log _log;
58
59 private Module _contributingModule;
60
61 public BuilderFactoryLogic(ServiceImplementationFactoryParameters factoryParameters,
62 BuilderParameter parameter)
63 {
64 _factoryParameters = factoryParameters;
65 _parameter = parameter;
66
67 _log = _factoryParameters.getLog();
68 _serviceId = factoryParameters.getServiceId();
69 _contributingModule = factoryParameters.getInvokingModule();
70 }
71
72 public Object createService()
73 {
74 try
75 {
76 Object result = instantiateCoreServiceInstance();
77
78 setProperties(result);
79
80 registerForEvents(result);
81
82 invokeInitializer(result);
83
84 return result;
85 }
86 catch (Exception ex)
87 {
88 throw new ApplicationRuntimeException(ServiceMessages.failureBuildingService(
89 _serviceId,
90 ex), _parameter.getLocation(), ex);
91 }
92 }
93
94 private void error(String message, Location location, Throwable cause)
95 {
96 _factoryParameters.getErrorLog().error(message, location, cause);
97 }
98
99 private Object instantiateCoreServiceInstance()
100 {
101 Class serviceClass = _contributingModule.resolveType(_parameter.getClassName());
102
103 List parameters = _parameter.getParameters();
104
105 if (_parameter.getAutowireServices() && parameters.isEmpty())
106 {
107 return instantiateConstructorAutowiredInstance(serviceClass);
108 }
109
110 return instantiateExplicitConstructorInstance(serviceClass, parameters);
111 }
112
113 private Object instantiateExplicitConstructorInstance(Class serviceClass, List builderParameters)
114 {
115 int numberOfParams = builderParameters.size();
116 List constructorCandidates = getServiceConstructorsOfLength(serviceClass, numberOfParams);
117
118 outer: for (Iterator candidates = constructorCandidates.iterator(); candidates.hasNext();)
119 {
120 Constructor candidate = (Constructor ) candidates.next();
121
122 Class [] parameterTypes = candidate.getParameterTypes();
123
124 Object [] parameters = new Object [parameterTypes.length];
125
126 for (int i = 0; i < numberOfParams; i++)
127 {
128 BuilderFacet facet = (BuilderFacet) builderParameters.get(i);
129
130 if (!facet.isAssignableToType(_factoryParameters, parameterTypes[i]))
131 continue outer;
132
133 parameters[i] = facet.getFacetValue(_factoryParameters, parameterTypes[i]);
134 }
135
136 return ConstructorUtils.invoke(candidate, parameters);
137 }
138
139 throw new ApplicationRuntimeException(ServiceMessages.unableToFindExplicitConstructor(),
140 _parameter.getLocation(), null);
141 }
142
143 private List getServiceConstructorsOfLength(Class serviceClass, int length)
144 {
145 List fixedLengthConstructors = new ArrayList ();
146
147 Constructor [] constructors = serviceClass.getDeclaredConstructors();
148
149 for (int i = 0; i < constructors.length; i++)
150 {
151 if (!Modifier.isPublic(constructors[i].getModifiers()))
152 continue;
153
154 Class [] parameterTypes = constructors[i].getParameterTypes();
155
156 if (parameterTypes.length != length)
157 continue;
158
159 fixedLengthConstructors.add(constructors[i]);
160 }
161
162 return fixedLengthConstructors;
163 }
164
165 private Object instantiateConstructorAutowiredInstance(Class serviceClass)
166 {
167 List serviceConstructorCandidates = getOrderedServiceConstructors(serviceClass);
168
169 outer: for (Iterator candidates = serviceConstructorCandidates.iterator(); candidates
170 .hasNext();)
171 {
172 Constructor candidate = (Constructor ) candidates.next();
173
174 Class [] parameterTypes = candidate.getParameterTypes();
175
176 Object [] parameters = new Object [parameterTypes.length];
177
178 for (int i = 0; i < parameters.length; i++)
179 {
180 BuilderFacet facet = _parameter.getFacetForType(
181 _factoryParameters,
182 parameterTypes[i]);
183
184 if (facet != null && facet.canAutowireConstructorParameter())
185 parameters[i] = facet.getFacetValue(_factoryParameters, parameterTypes[i]);
186 else if (_contributingModule.containsService(parameterTypes[i]))
187 parameters[i] = _contributingModule.getService(parameterTypes[i]);
188 else
189 continue outer;
190 }
191
192 return ConstructorUtils.invoke(candidate, parameters);
193 }
194
195 throw new ApplicationRuntimeException(ServiceMessages.unableToFindAutowireConstructor(),
196 _parameter.getLocation(), null);
197 }
198
199 private List getOrderedServiceConstructors(Class serviceClass)
200 {
201 List orderedInterfaceConstructors = new ArrayList ();
202
203 Constructor [] constructors = serviceClass.getDeclaredConstructors();
204
205 outer: for (int i = 0; i < constructors.length; i++)
206 {
207 if (!Modifier.isPublic(constructors[i].getModifiers()))
208 continue;
209
210 Class [] parameterTypes = constructors[i].getParameterTypes();
211
212 if (parameterTypes.length > 0)
213 {
214 Set seenTypes = new HashSet ();
215
216 for (int j = 0; j < parameterTypes.length; j++)
217 {
218 if (!parameterTypes[j].isInterface() || seenTypes.contains(parameterTypes[j]))
219 continue outer;
220
221 seenTypes.add(parameterTypes[j]);
222 }
223 }
224
225 orderedInterfaceConstructors.add(constructors[i]);
226 }
227
228 Collections.sort(orderedInterfaceConstructors, new Comparator ()
229 {
230 public int compare(Object o1, Object o2)
231 {
232 return ((Constructor ) o2).getParameterTypes().length
233 - ((Constructor ) o1).getParameterTypes().length;
234 }
235 });
236
237 return orderedInterfaceConstructors;
238 }
239
240 private void invokeInitializer(Object service)
241 {
242 String methodName = _parameter.getInitializeMethod();
243
244 boolean allowMissing = HiveMind.isBlank(methodName);
245
246 String searchMethodName = allowMissing ? "initializeService" : methodName;
247
248 try
249 {
250 findAndInvokeInitializerMethod(service, searchMethodName, allowMissing);
251 }
252 catch (InvocationTargetException ex)
253 {
254 Throwable cause = ex.getTargetException();
255
256 error(ServiceMessages.unableToInitializeService(_serviceId, searchMethodName, service
257 .getClass(), cause), _parameter.getLocation(), cause);
258 }
259 catch (Exception ex)
260 {
261 error(ServiceMessages.unableToInitializeService(_serviceId, searchMethodName, service
262 .getClass(), ex), _parameter.getLocation(), ex);
263 }
264 }
265
266 private void findAndInvokeInitializerMethod(Object service, String methodName,
267 boolean allowMissing) throws IllegalAccessException , InvocationTargetException ,
268 NoSuchMethodException
269 {
270 Class serviceClass = service.getClass();
271
272 try
273 {
274 Method m = serviceClass.getMethod(methodName, (Class []) null);
275
276 m.invoke(service, (Object []) null);
277 }
278 catch (NoSuchMethodException ex)
279 {
280 if (allowMissing)
281 return;
282
283 throw ex;
284 }
285 }
286
287 private void registerForEvents(Object result)
288 {
289 List eventRegistrations = _parameter.getEventRegistrations();
290
291 if (eventRegistrations.isEmpty())
292 return;
293
294 EventLinker linker = new EventLinkerImpl(_factoryParameters.getErrorLog());
295
296 Iterator i = eventRegistrations.iterator();
297 while (i.hasNext())
298 {
299 EventRegistration er = (EventRegistration) i.next();
300
301
303 linker.addEventListener(er.getProducer(), er.getEventSetName(), result, er
304 .getLocation());
305 }
306 }
307
308 private void setProperties(Object service)
309 {
310 List properties = _parameter.getProperties();
311 int count = properties.size();
312
313
315 Set writeableProperties = new HashSet (PropertyUtils.getWriteableProperties(service));
316
317 for (int i = 0; i < count; i++)
318 {
319 BuilderFacet facet = (BuilderFacet) properties.get(i);
320
321 String propertyName = wireProperty(service, facet);
322
323 if (propertyName != null)
324 writeableProperties.remove(propertyName);
325 }
326
327 if (_parameter.getAutowireServices() && !writeableProperties.isEmpty())
328 autowireServices(service, writeableProperties);
329
330 }
331
332
336 private String wireProperty(Object service, BuilderFacet facet)
337 {
338 String propertyName = facet.getPropertyName();
339
340 try
341 {
342
344 String autowirePropertyName = facet.autowire(service, _factoryParameters);
345
346 if (autowirePropertyName != null)
347 return autowirePropertyName;
348
349
353 if (propertyName == null)
354 return null;
355
356 Class targetType = PropertyUtils.getPropertyType(service, propertyName);
357
358 Object value = facet.getFacetValue(_factoryParameters, targetType);
359
360 PropertyUtils.write(service, propertyName, value);
361
362 if (_log.isDebugEnabled())
363 _log.debug("Set property " + propertyName + " to " + value);
364
365 return propertyName;
366 }
367 catch (Exception ex)
368 {
369 error(ex.getMessage(), facet.getLocation(), ex);
370
371 return null;
372 }
373 }
374
375 private void autowireServices(Object service, Collection propertyNames)
376 {
377 Autowiring autowiring = (Autowiring) _contributingModule.getService(HiveMind.AUTOWIRING_SERVICE, Autowiring.class);
378
379 String [] props = (String []) propertyNames.toArray(new String [propertyNames.size()]);
380 autowiring.autowireProperties(AutowiringStrategy.BY_TYPE, service, props);
381 }
382
383
384 } |
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