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1
8 package org.apache.avalon.excalibur.component;
9
10 import java.util.ArrayList  ;
11 import java.util.Collections ;
12 import java.util.HashMap ;
13 import java.util.Iterator ;
14 import java.util.List ;
15 import java.util.Map ;
16 import org.apache.avalon.framework.activity.Disposable;
17 import org.apache.avalon.framework.activity.Initializable;
18 import org.apache.avalon.framework.component.Component;
19 import org.apache.avalon.framework.component.ComponentException;
20 import org.apache.avalon.framework.component.ComponentManager;
21 import org.apache.avalon.framework.component.ComponentSelector;
22 import org.apache.avalon.framework.component.Composable;
23 import org.apache.avalon.framework.configuration.Configurable;
24 import org.apache.avalon.framework.configuration.Configuration;
25 import org.apache.avalon.framework.configuration.ConfigurationException;
26 import org.apache.avalon.framework.context.Context;
27 import org.apache.avalon.framework.context.Contextualizable;
28 import org.apache.avalon.framework.logger.AbstractLoggable;
29 import org.apache.avalon.framework.thread.ThreadSafe;
30 import org.apache.avalon.excalibur.logger.LogKitManager;
31 import org.apache.avalon.excalibur.logger.LogKitManageable;
32
33
41 public class ExcaliburComponentSelector
42 extends AbstractLoggable
43 implements Contextualizable,
44 ComponentSelector,
45 Composable,
46 Configurable,
47 Initializable,
48 ThreadSafe,
49 Disposable,
50 RoleManageable,
51 LogKitManageable
52 {
53
54 private final ClassLoader m_loader;
55
56
58 private static final String DEFAULT_NAME = "UnnamedSelector";
59
60
62 private String m_rolename;
63
64
66 protected Context m_context;
67
68
70 private ComponentManager m_componentManager;
71
72
74 private Map m_componentMapping;
75
76
78 private Configuration m_configuration;
79
80
82 private Map m_componentHandlers;
83
84
86 private boolean m_disposed;
87
88
90 private boolean m_initialized;
91
92
94 private RoleManager m_roles;
95
96
98 private LogKitManager m_logkit;
99
100
101 public ExcaliburComponentSelector()
102 {
103 this(Thread.currentThread().getContextClassLoader());
104 }
105
106
107 public ExcaliburComponentSelector(final ClassLoader loader)
108 {
109 if (loader == null)
110 {
111 m_loader = Thread.currentThread().getContextClassLoader();
112 }
113 else
114 {
115 m_loader = loader;
116 }
117
118 m_componentHandlers = Collections.synchronizedMap( new HashMap () );
120 m_componentMapping = Collections.synchronizedMap( new HashMap () );
121 }
122
123
125 public void contextualize( final Context context )
126 {
127 if( null == m_context )
128 {
129 m_context = context;
130 }
131 }
132
133
135 public void compose( final ComponentManager componentManager )
136 throws ComponentException
137 {
138 if( null == m_componentManager )
140 {
141 m_componentManager = componentManager;
142 }
143 }
144
145
147 public void initialize( )
148 {
149 synchronized( this )
150 {
151 m_initialized = true;
152
153 List keys = new ArrayList (m_componentHandlers.keySet());
154
155 for(int i = 0; i < keys.size(); i++ )
156 {
157 final Object key = keys.get(i);
158 final ComponentHandler handler =
159 (ComponentHandler)m_componentHandlers.get( key );
160
161 try
162 {
163 handler.initialize();
164 }
165 catch (Exception e)
166 {
167 if (getLogger().isDebugEnabled())
168 {
169 getLogger().debug( "Caught an exception trying to initialize " +
170 "of the component handler.", e );
171 }
172 }
173
174 }
175 }
176 }
177
178
181 public boolean hasComponent( final Object hint )
182 {
183 if ( ! m_initialized ) return false;
184 if ( m_disposed ) return false;
185
186 boolean exists = false;
187
188 try
189 {
190 this.release( this.select( hint ) );
191 exists = true;
192 }
193 catch ( Throwable t )
194 {
195 }
197
198 return exists;
199 }
200
201
204 public void dispose()
205 {
206 synchronized(this)
207 {
208 Iterator keys = m_componentHandlers.keySet().iterator();
209 List keyList = new ArrayList ();
210
211 while( keys.hasNext() )
212 {
213 Object key = keys.next();
214 ComponentHandler handler =
215 (ComponentHandler)m_componentHandlers.get( key );
216
217 handler.dispose();
218
219 keyList.add( key );
220 }
221
222 keys = keyList.iterator();
223
224 while( keys.hasNext() )
225 {
226 m_componentHandlers.remove( keys.next() );
227 }
228
229 keyList.clear();
230
231 m_disposed = true;
232 }
233 }
234
235
239 public Component select( final Object hint )
240 throws ComponentException
241 {
242 if( !m_initialized )
243 {
244 if (getLogger().isWarnEnabled()) {
245 getLogger().warn("Looking up component on an uninitialized ComponentManager: " + hint);
246 }
247 }
248
249
250 if( m_disposed )
251 {
252 throw new IllegalStateException ( "You cannot select a Component from a disposed ComponentSelector" );
253 }
254
255 if( null == hint )
256 {
257 final String message = getName() + ": ComponentSelector Attempted to retrieve component with null hint.";
258 if (getLogger().isErrorEnabled())
259 {
260 getLogger().error( message );
261 }
262
263 throw new ComponentException( message );
264 }
265
266 ComponentHandler handler = (ComponentHandler)m_componentHandlers.get( hint );
267
268 if( null == handler )
270 {
271 final String message = getName() + ": ComponentSelector could not find the component for hint: " + hint;
272 if (getLogger().isDebugEnabled())
273 {
274 getLogger().debug( message );
275 }
276 throw new ComponentException( message );
277 }
278
279 Component component = null;
280
281 try
282 {
283 component = handler.get();
284 }
285 catch( final Exception e )
286 {
287 final String message = getName() + ": ComponentSelector could not access the Component for hint: " + hint;
288
289 if (getLogger().isDebugEnabled())
290 {
291 getLogger().debug( message, e );
292 }
293 throw new ComponentException( message, e );
294 }
295
296 if( null == component )
297 {
298 final String message = getName() + ": ComponentSelector could not find the component for hint: " + hint;
299 if (getLogger().isDebugEnabled())
300 {
301 getLogger().debug( message );
302 }
303 throw new ComponentException( message );
304 }
305
306 m_componentMapping.put( component, handler );
307 return component;
308 }
309
310
313 public void configure( final Configuration configuration )
314 throws ConfigurationException
315 {
316 m_configuration = configuration;
317
318 if (getLogger().isDebugEnabled())
319 {
320 getLogger().debug( "ComponentSelector setting up with root element: " +
321 m_configuration.getName() );
322 }
323
324 final String name = configuration.getName();
325 if( name.equals( "component" ) )
326 {
327 m_rolename = m_configuration.getAttribute( "role" );
328 }
329 else
330 {
331 m_rolename = m_roles.getRoleForName( name );
332 }
333
334 Configuration[] instances = m_configuration.getChildren();
335
336 for( int i = 0; i < instances.length; i++ )
337 {
338 final Object hint = instances[ i ].getAttribute( "name" ).trim();
339 final String className;
340
341 if( "component-instance".equals( instances[i].getName() ) )
342 {
343 className = (String )instances[i].getAttribute( "class" ).trim();
344 }
345 else
346 {
347 className = m_roles.getDefaultClassNameForHint( m_rolename,
348 instances[i].getName() );
349 }
350
351 try
352 {
353 final Class clazz = m_loader.loadClass( className );
354 addComponent( hint, clazz, instances[i]);
355 }
356 catch( final ClassNotFoundException cnfe )
357 {
358 final String message =
359 "The component instance for '" + hint +
360 "' has an invalid class name (" + className + ").";
361 if (getLogger().isErrorEnabled())
362 {
363 getLogger().error( message, cnfe );
364 }
365
366 throw new ConfigurationException( message, cnfe );
367 }
368 catch( final ComponentException ce )
369 {
370 if (getLogger().isErrorEnabled())
371 {
372 getLogger().error( "The component instance for '" + hint +
373 "' is not valid.", ce );
374 }
375
376 throw new ConfigurationException( "Could not set up component", ce );
377 }
378 catch( final Exception e )
379 {
380 if (getLogger().isErrorEnabled())
381 {
382 getLogger().error("Unexpected exception for hint: " + hint, e);
383 }
384 throw new ConfigurationException( "Unexpected exception", e );
385 }
386 }
387 }
388
389
392 public void setRoleManager( final RoleManager roles )
393 {
394 if( null == m_roles )
395 {
396 m_roles = roles;
397 }
398 }
399
400
403 public void setLogKitManager( final LogKitManager logkit )
404 {
405 if( null == m_logkit )
406 {
407 m_logkit = logkit;
408 }
409 }
410
411
414 public void release( final Component component )
415 {
416 if( null == component )
417 {
418 return;
419 }
420
421 final ComponentHandler handler =
422 (ComponentHandler)m_componentMapping.get( component );
423
424 if( null == handler )
425 {
426 return;
427 }
428
429 try {
430 handler.put( component );
431 } catch (Exception e) {
432 if (getLogger().isDebugEnabled())
433 {
434 getLogger().debug("Error trying to release component", e);
435 }
436 }
437
438 m_componentMapping.remove( component );
439 }
440
441
446 public void addComponent( final Object hint,
447 final Class component,
448 final Configuration configuration )
449 throws ComponentException
450 {
451 if ( m_initialized )
452 {
453 throw new ComponentException("Cannot add components to an initialized ComponentSelector", null);
454 }
455
456 try
457 {
458 final ComponentHandler handler =
459 ComponentHandler.getComponentHandler( component,
460 configuration,
461 m_componentManager,
462 m_context,
463 m_roles,
464 m_logkit );
465
466 handler.setLogger( getLogger() );
467 handler.initialize();
468 m_componentHandlers.put( hint, handler );
469
470 if (getLogger().isDebugEnabled())
471 {
472 getLogger().debug( "Adding " + component.getName() + " for " + hint.toString() );
473 }
474 }
475 catch( final Exception e )
476 {
477 final String message =
478 "Could not set up Component for hint: " + hint;
479 if (getLogger().isErrorEnabled())
480 {
481 getLogger().error( message, e);
482 }
483
484 throw new ComponentException( message, e );
485 }
486 }
487
488
492 public void addComponentInstance( final Object hint, final Component instance )
493 {
494 if ( m_initialized )
495 {
496 throw new IllegalStateException ("Cannot add components to an initialized ComponentSelector");
497 }
498
499 try
500 {
501 final ComponentHandler handler =
502 ComponentHandler.getComponentHandler( instance );
503 handler.setLogger( getLogger() );
504 handler.initialize();
505 m_componentHandlers.put( hint, handler );
506
507 if (getLogger().isDebugEnabled())
508 {
509 getLogger().debug( "Adding " + instance.getClass().getName() +
510 " for " + hint.toString() );
511 }
512 }
513 catch( final Exception e )
514 {
515 if (getLogger().isErrorEnabled())
516 {
517 getLogger().error( "Could not set up Component for hint: " + hint, e );
518 }
519 }
520 }
521
522
528 private String getName()
529 {
530 if( null != m_configuration &&
531 !m_configuration.getName().equals( "" ) )
532 {
533 return m_configuration.getName();
534 }
535
536 return DEFAULT_NAME;
537 }
538 }
539 |
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