Source Code Cross Referenced for TurbinePoolService.java in  » Web-Framework » TURBINE » org » apache » turbine » services » pool » Java Source Code / Java DocumentationJava Source Code and Java Documentation

Java Source Code / Java Documentation
1. 6.0 JDK Core
2. 6.0 JDK Modules
3. 6.0 JDK Modules com.sun
4. 6.0 JDK Modules com.sun.java
5. 6.0 JDK Modules sun
6. 6.0 JDK Platform
7. Ajax
8. Apache Harmony Java SE
9. Aspect oriented
10. Authentication Authorization
11. Blogger System
12. Build
13. Byte Code
14. Cache
15. Chart
16. Chat
17. Code Analyzer
18. Collaboration
19. Content Management System
20. Database Client
21. Database DBMS
22. Database JDBC Connection Pool
23. Database ORM
24. Development
25. EJB Server geronimo
26. EJB Server GlassFish
27. EJB Server JBoss 4.2.1
28. EJB Server resin 3.1.5
29. ERP CRM Financial
30. ESB
31. Forum
32. GIS
33. Graphic Library
34. Groupware
35. HTML Parser
36. IDE
37. IDE Eclipse
38. IDE Netbeans
39. Installer
40. Internationalization Localization
41. Inversion of Control
42. Issue Tracking
43. J2EE
44. JBoss
45. JMS
46. JMX
47. Library
48. Mail Clients
49. Net
50. Parser
51. PDF
52. Portal
53. Profiler
54. Project Management
55. Report
56. RSS RDF
57. Rule Engine
58. Science
59. Scripting
60. Search Engine
61. Security
62. Sevlet Container
63. Source Control
64. Swing Library
65. Template Engine
66. Test Coverage
67. Testing
68. UML
69. Web Crawler
70. Web Framework
71. Web Mail
72. Web Server
73. Web Services
74. Web Services apache cxf 2.0.1
75. Web Services AXIS2
76. Wiki Engine
77. Workflow Engines
78. XML
79. XML UI
Java
Java Tutorial
Java Open Source
Jar File Download
Java Articles
Java Products
Java by API
Photoshop Tutorials
Maya Tutorials
Flash Tutorials
3ds-Max Tutorials
Illustrator Tutorials
GIMP Tutorials
C# / C Sharp
C# / CSharp Tutorial
C# / CSharp Open Source
ASP.Net
ASP.NET Tutorial
JavaScript DHTML
JavaScript Tutorial
JavaScript Reference
HTML / CSS
HTML CSS Reference
C / ANSI-C
C Tutorial
C++
C++ Tutorial
Ruby
PHP
Python
Python Tutorial
Python Open Source
SQL Server / T-SQL
SQL Server / T-SQL Tutorial
Oracle PL / SQL
Oracle PL/SQL Tutorial
PostgreSQL
SQL / MySQL
MySQL Tutorial
VB.Net
VB.Net Tutorial
Flash / Flex / ActionScript
VBA / Excel / Access / Word
XML
XML Tutorial
Microsoft Office PowerPoint 2007 Tutorial
Microsoft Office Excel 2007 Tutorial
Microsoft Office Word 2007 Tutorial
Java Source Code / Java Documentation » Web Framework » TURBINE » org.apache.turbine.services.pool 
Source Cross Referenced  Class Diagram Java Document (Java Doc) 


001:        package org.apache.turbine.services.pool;
002:
003:        /*
004:         * Licensed to the Apache Software Foundation (ASF) under one
005:         * or more contributor license agreements.  See the NOTICE file
006:         * distributed with this work for additional information
007:         * regarding copyright ownership.  The ASF licenses this file
008:         * to you under the Apache License, Version 2.0 (the
009:         * "License"); you may not use this file except in compliance
010:         * with the License.  You may obtain a copy of the License at
011:         *
012:         *   http://www.apache.org/licenses/LICENSE-2.0
013:         *
014:         * Unless required by applicable law or agreed to in writing,
015:         * software distributed under the License is distributed on an
016:         * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017:         * KIND, either express or implied.  See the License for the
018:         * specific language governing permissions and limitations
019:         * under the License.
020:         */
021:
022:        import java.lang.reflect.Method;
023:
024:        import java.util.ArrayList;
025:        import java.util.HashMap;
026:        import java.util.Iterator;
027:
028:        import org.apache.commons.configuration.Configuration;
029:
030:        import org.apache.commons.logging.Log;
031:        import org.apache.commons.logging.LogFactory;
032:
033:        import org.apache.turbine.services.InitializationException;
034:        import org.apache.turbine.services.TurbineBaseService;
035:        import org.apache.turbine.services.factory.FactoryService;
036:        import org.apache.turbine.services.factory.TurbineFactory;
037:        import org.apache.turbine.util.TurbineException;
038:        import org.apache.turbine.util.pool.ArrayCtorRecyclable;
039:        import org.apache.turbine.util.pool.BoundedBuffer;
040:        import org.apache.turbine.util.pool.Recyclable;
041:
042:        /**
043:         * The Pool Service extends the Factory Service by adding support
044:         * for pooling instantiated objects. When a new instance is
045:         * requested, the service first checks its pool if one is available.
046:         * If the the pool is empty, a new instance will be requested
047:         * from the FactoryService.
048:         *
049:         * <p>For objects implementing the Recyclable interface, a recycle
050:         * method will be called, when they taken from the pool, and
051:         * a dispose method, when they are returned to the pool.
052:         *
053:         * @author <a href="mailto:ilkka.priha@simsoft.fi">Ilkka Priha</a>
054:         * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
055:         * @version $Id: TurbinePoolService.java 534527 2007-05-02 16:10:59Z tv $
056:         */
057:        public class TurbinePoolService extends TurbineBaseService implements 
058:                PoolService {
059:            /** Are we currently debugging the pool recycling? */
060:            private boolean debugPool = false;
061:
062:            /** Internal Reference to the Factory */
063:            private FactoryService factoryService;
064:
065:            /** Logging */
066:            private static Log log = LogFactory
067:                    .getLog(TurbinePoolService.class);
068:
069:            /**
070:             * An inner class for class specific pools.
071:             */
072:            private class PoolBuffer {
073:                /**
074:                 * An inner class for cached recycle methods.
075:                 */
076:                private class Recycler {
077:                    /** The recycle method. */
078:                    private final Method recycle;
079:
080:                    /** The signature. */
081:                    private final String[] signature;
082:
083:                    /**
084:                     * Constructs a new recycler.
085:                     *
086:                     * @param rec the recycle method.
087:                     * @param sign the signature.
088:                     */
089:                    public Recycler(Method rec, String[] sign) {
090:                        recycle = rec;
091:                        signature = ((sign != null) && (sign.length > 0)) ? sign
092:                                : null;
093:                    }
094:
095:                    /**
096:                     * Matches the given signature against
097:                     * that of the recycle method of this recycler.
098:                     *
099:                     * @param sign the signature.
100:                     * @return the matching recycle method or null.
101:                     */
102:                    public Method match(String[] sign) {
103:                        if ((sign != null) && (sign.length > 0)) {
104:                            if ((signature != null)
105:                                    && (sign.length == signature.length)) {
106:                                for (int i = 0; i < signature.length; i++) {
107:                                    if (!signature[i].equals(sign[i])) {
108:                                        return null;
109:                                    }
110:                                }
111:                                return recycle;
112:                            } else {
113:                                return null;
114:                            }
115:                        } else if (signature == null) {
116:                            return recycle;
117:                        } else {
118:                            return null;
119:                        }
120:                    }
121:                }
122:
123:                /** A buffer for class instances. */
124:                private BoundedBuffer pool;
125:
126:                /** A flag to determine if a more efficient recycler is implemented. */
127:                private boolean arrayCtorRecyclable;
128:
129:                /** A cache for recycling methods. */
130:                private ArrayList recyclers;
131:
132:                /**
133:                 * Constructs a new pool buffer with a specific capacity.
134:                 *
135:                 * @param capacity a capacity.
136:                 */
137:                public PoolBuffer(int capacity) {
138:                    pool = new BoundedBuffer(capacity);
139:                }
140:
141:                /**
142:                 * Tells pool that it contains objects which can be
143:                 * initialized using an Object array.
144:                 *
145:                 * @param isArrayCtor a <code>boolean</code> value
146:                 */
147:                public void setArrayCtorRecyclable(boolean isArrayCtor) {
148:                    arrayCtorRecyclable = isArrayCtor;
149:                }
150:
151:                /**
152:                 * Polls for an instance from the pool.
153:                 *
154:                 * @return an instance or null.
155:                 */
156:                public Object poll(Object[] params, String[] signature)
157:                        throws TurbineException {
158:                    // If we're debugging the recycling code, we want different
159:                    // objects to be used when pulling from the pool. Ensure that
160:                    // each pool fills up at least to half its capacity.
161:                    if (debugPool && (pool.size() < (pool.capacity() / 2))) {
162:                        log.debug("Size: " + pool.size() + ", capacity: "
163:                                + pool.capacity());
164:                        return null;
165:                    }
166:
167:                    Object instance = pool.poll();
168:                    if (instance != null) {
169:                        if (arrayCtorRecyclable) {
170:                            ((ArrayCtorRecyclable) instance).recycle(params);
171:                        } else if (instance instanceof  Recyclable) {
172:                            try {
173:                                if ((signature != null)
174:                                        && (signature.length > 0)) {
175:                                    /* Get the recycle method from the cache. */
176:                                    Method recycle = getRecycle(signature);
177:                                    if (recycle == null) {
178:                                        synchronized (this ) {
179:                                            /* Make a synchronized recheck. */
180:                                            recycle = getRecycle(signature);
181:                                            if (recycle == null) {
182:                                                Class clazz = instance
183:                                                        .getClass();
184:                                                recycle = clazz
185:                                                        .getMethod(
186:                                                                "recycle",
187:                                                                factoryService
188:                                                                        .getSignature(
189:                                                                                clazz,
190:                                                                                params,
191:                                                                                signature));
192:                                                ArrayList cache = recyclers != null ? (ArrayList) recyclers
193:                                                        .clone()
194:                                                        : new ArrayList();
195:                                                cache.add(new Recycler(recycle,
196:                                                        signature));
197:                                                recyclers = cache;
198:                                            }
199:                                        }
200:                                    }
201:                                    recycle.invoke(instance, params);
202:                                } else {
203:                                    ((Recyclable) instance).recycle();
204:                                }
205:                            } catch (Exception x) {
206:                                throw new TurbineException(
207:                                        "Recycling failed for "
208:                                                + instance.getClass().getName(),
209:                                        x);
210:                            }
211:                        }
212:                    }
213:                    return instance;
214:                }
215:
216:                /**
217:                 * Offers an instance to the pool.
218:                 *
219:                 * @param instance an instance.
220:                 */
221:                public boolean offer(Object instance) {
222:                    if (instance instanceof  Recyclable) {
223:                        try {
224:                            ((Recyclable) instance).dispose();
225:                        } catch (Exception x) {
226:                            return false;
227:                        }
228:                    }
229:                    return pool.offer(instance);
230:                }
231:
232:                /**
233:                 * Returns the capacity of the pool.
234:                 *
235:                 * @return the capacity.
236:                 */
237:                public int capacity() {
238:                    return pool.capacity();
239:                }
240:
241:                /**
242:                 * Returns the size of the pool.
243:                 *
244:                 * @return the size.
245:                 */
246:                public int size() {
247:                    return pool.size();
248:                }
249:
250:                /**
251:                 * Returns a cached recycle method
252:                 * corresponding to the given signature.
253:                 *
254:                 * @param signature the signature.
255:                 * @return the recycle method or null.
256:                 */
257:                private Method getRecycle(String[] signature) {
258:                    ArrayList cache = recyclers;
259:                    if (cache != null) {
260:                        Method recycle;
261:                        for (Iterator i = cache.iterator(); i.hasNext();) {
262:                            recycle = ((Recycler) i.next()).match(signature);
263:                            if (recycle != null) {
264:                                return recycle;
265:                            }
266:                        }
267:                    }
268:                    return null;
269:                }
270:            }
271:
272:            /**
273:             * The default capacity of pools.
274:             */
275:            private int poolCapacity = DEFAULT_POOL_CAPACITY;
276:
277:            /**
278:             * The pool repository, one pool for each class.
279:             */
280:            private HashMap poolRepository = new HashMap();
281:
282:            /**
283:             * Constructs a Pool Service.
284:             */
285:            public TurbinePoolService() {
286:            }
287:
288:            /**
289:             * Initializes the service by setting the pool capacity.
290:             *
291:             * @param config initialization configuration.
292:             * @throws InitializationException if initialization fails.
293:             */
294:            public void init() throws InitializationException {
295:                Configuration conf = getConfiguration();
296:
297:                int capacity = conf.getInt(POOL_CAPACITY_KEY,
298:                        DEFAULT_POOL_CAPACITY);
299:
300:                if (capacity <= 0) {
301:                    throw new IllegalArgumentException("Capacity must be >0");
302:                }
303:                poolCapacity = capacity;
304:
305:                debugPool = conf.getBoolean(POOL_DEBUG_KEY, POOL_DEBUG_DEFAULT);
306:
307:                if (debugPool) {
308:                    log.info("Activated Pool Debugging!");
309:                }
310:
311:                factoryService = TurbineFactory.getService();
312:
313:                if (factoryService == null) {
314:                    throw new InitializationException(
315:                            "Factory Service is not configured"
316:                                    + " but required for the Pool Service!");
317:                }
318:
319:                setInit(true);
320:            }
321:
322:            /**
323:             * Gets an instance of a named class either from the pool
324:             * or by calling the Factory Service if the pool is empty.
325:             *
326:             * @param className the name of the class.
327:             * @return the instance.
328:             * @throws TurbineException if recycling fails.
329:             */
330:            public Object getInstance(String className) throws TurbineException {
331:                Object instance = pollInstance(className, null, null);
332:                return (instance == null) ? factoryService
333:                        .getInstance(className) : instance;
334:            }
335:
336:            /**
337:             * Gets an instance of a named class either from the pool
338:             * or by calling the Factory Service if the pool is empty.
339:             * The specified class loader will be passed to the Factory Service.
340:             *
341:             * @param className the name of the class.
342:             * @param loader the class loader.
343:             * @return the instance.
344:             * @throws TurbineException if recycling fails.
345:             */
346:            public Object getInstance(String className, ClassLoader loader)
347:                    throws TurbineException {
348:                Object instance = pollInstance(className, null, null);
349:                return (instance == null) ? factoryService.getInstance(
350:                        className, loader) : instance;
351:            }
352:
353:            /**
354:             * Gets an instance of a named class either from the pool
355:             * or by calling the Factory Service if the pool is empty.
356:             * Parameters for its constructor are given as an array of objects,
357:             * primitive types must be wrapped with a corresponding class.
358:             *
359:             * @param className the name of the class.
360:             * @param loader the class loader.
361:             * @param params an array containing the parameters of the constructor.
362:             * @param signature an array containing the signature of the constructor.
363:             * @return the instance.
364:             * @throws TurbineException if recycling fails.
365:             */
366:            public Object getInstance(String className, Object[] params,
367:                    String[] signature) throws TurbineException {
368:                Object instance = pollInstance(className, params, signature);
369:                return (instance == null) ? factoryService.getInstance(
370:                        className, params, signature) : instance;
371:            }
372:
373:            /**
374:             * Gets an instance of a named class either from the pool
375:             * or by calling the Factory Service if the pool is empty.
376:             * Parameters for its constructor are given as an array of objects,
377:             * primitive types must be wrapped with a corresponding class.
378:             * The specified class loader will be passed to the Factory Service.
379:             *
380:             * @param className the name of the class.
381:             * @param loader the class loader.
382:             * @param params an array containing the parameters of the constructor.
383:             * @param signature an array containing the signature of the constructor.
384:             * @return the instance.
385:             * @throws TurbineException if recycling fails.
386:             */
387:            public Object getInstance(String className, ClassLoader loader,
388:                    Object[] params, String[] signature)
389:                    throws TurbineException {
390:                Object instance = pollInstance(className, params, signature);
391:                return (instance == null) ? factoryService.getInstance(
392:                        className, loader, params, signature) : instance;
393:            }
394:
395:            /**
396:             * Tests if specified class loaders are supported for a named class.
397:             *
398:             * @param className the name of the class.
399:             * @return true if class loaders are supported, false otherwise.
400:             * @throws TurbineException if test fails.
401:             * @deprecated Use TurbineFactory.isLoaderSupported(className);
402:             */
403:            public boolean isLoaderSupported(String className)
404:                    throws TurbineException {
405:                return factoryService.isLoaderSupported(className);
406:            }
407:
408:            /**
409:             * Gets an instance of a specified class either from the pool
410:             * or by instatiating from the class if the pool is empty.
411:             *
412:             * @param clazz the class.
413:             * @return the instance.
414:             * @throws TurbineException if recycling fails.
415:             */
416:            public Object getInstance(Class clazz) throws TurbineException {
417:                Object instance = pollInstance(clazz.getName(), null, null);
418:                return (instance == null) ? factoryService.getInstance(clazz
419:                        .getName()) : instance;
420:            }
421:
422:            /**
423:             * Gets an instance of a specified class either from the pool
424:             * or by instatiating from the class if the pool is empty.
425:             *
426:             * @param clazz the class.
427:             * @param params an array containing the parameters of the constructor.
428:             * @param signature an array containing the signature of the constructor.
429:             * @return the instance.
430:             * @throws TurbineException if recycling fails.
431:             */
432:            public Object getInstance(Class clazz, Object params[],
433:                    String signature[]) throws TurbineException {
434:                Object instance = pollInstance(clazz.getName(), params,
435:                        signature);
436:                return (instance == null) ? factoryService.getInstance(clazz
437:                        .getName(), params, signature) : instance;
438:            }
439:
440:            /**
441:             * Puts a used object back to the pool. Objects implementing
442:             * the Recyclable interface can provide a recycle method to
443:             * be called when they are reused and a dispose method to be
444:             * called when they are returned to the pool.
445:             *
446:             * @param instance the object instance to recycle.
447:             * @return true if the instance was accepted.
448:             */
449:            public boolean putInstance(Object instance) {
450:                if (instance != null) {
451:                    HashMap repository = poolRepository;
452:                    String className = instance.getClass().getName();
453:                    PoolBuffer pool = (PoolBuffer) repository.get(className);
454:                    if (pool == null) {
455:                        pool = new PoolBuffer(getCapacity(className));
456:                        repository = (HashMap) repository.clone();
457:                        repository.put(className, pool);
458:                        poolRepository = repository;
459:
460:                        if (instance instanceof  ArrayCtorRecyclable) {
461:                            pool.setArrayCtorRecyclable(true);
462:                        }
463:                    }
464:                    return pool.offer(instance);
465:                } else {
466:                    return false;
467:                }
468:            }
469:
470:            /**
471:             * Gets the capacity of the pool for a named class.
472:             *
473:             * @param className the name of the class.
474:             */
475:            public int getCapacity(String className) {
476:                PoolBuffer pool = (PoolBuffer) poolRepository.get(className);
477:                if (pool == null) {
478:                    /* Check class specific capacity. */
479:                    int capacity;
480:
481:                    Configuration conf = getConfiguration();
482:                    capacity = conf.getInt(POOL_CAPACITY_KEY + '.' + className,
483:                            poolCapacity);
484:                    capacity = (capacity <= 0) ? poolCapacity : capacity;
485:                    return capacity;
486:                } else {
487:                    return pool.capacity();
488:                }
489:            }
490:
491:            /**
492:             * Sets the capacity of the pool for a named class.
493:             * Note that the pool will be cleared after the change.
494:             *
495:             * @param className the name of the class.
496:             * @param capacity the new capacity.
497:             */
498:            public void setCapacity(String className, int capacity) {
499:                HashMap repository = poolRepository;
500:                repository = (repository != null) ? (HashMap) repository
501:                        .clone() : new HashMap();
502:
503:                capacity = (capacity <= 0) ? poolCapacity : capacity;
504:
505:                repository.put(className, new PoolBuffer(capacity));
506:                poolRepository = repository;
507:            }
508:
509:            /**
510:             * Gets the current size of the pool for a named class.
511:             *
512:             * @param className the name of the class.
513:             */
514:            public int getSize(String className) {
515:                PoolBuffer pool = (PoolBuffer) poolRepository.get(className);
516:                return (pool != null) ? pool.size() : 0;
517:            }
518:
519:            /**
520:             * Clears instances of a named class from the pool.
521:             *
522:             * @param className the name of the class.
523:             */
524:            public void clearPool(String className) {
525:                HashMap repository = poolRepository;
526:                if (repository.get(className) != null) {
527:                    repository = (HashMap) repository.clone();
528:                    repository.remove(className);
529:                    poolRepository = repository;
530:                }
531:            }
532:
533:            /**
534:             * Clears all instances from the pool.
535:             */
536:            public void clearPool() {
537:                poolRepository = new HashMap();
538:            }
539:
540:            /**
541:             * Polls and recycles an object of the named class from the pool.
542:             *
543:             * @param className the name of the class.
544:             * @param params an array containing the parameters of the constructor.
545:             * @param signature an array containing the signature of the constructor.
546:             * @return the object or null.
547:             * @throws TurbineException if recycling fails.
548:             */
549:            private Object pollInstance(String className, Object[] params,
550:                    String[] signature) throws TurbineException {
551:                PoolBuffer pool = (PoolBuffer) poolRepository.get(className);
552:                return (pool != null) ? pool.poll(params, signature) : null;
553:            }
554:        }
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.