eu.etaxonomy.taxeditor.cdmlib/src/main/java/org/hibernate/proxy/AbstractLazyInitializer.java

   1 /*
   2  * Hibernate, Relational Persistence for Idiomatic Java
   3  *
   4  * Copyright (c) 2008-2011, Red Hat Inc. or third-party contributors as
   5  * indicated by the @author tags or express copyright attribution
   6  * statements applied by the authors.  All third-party contributions are
   7  * distributed under license by Red Hat Inc.
   8  *
   9  * This copyrighted material is made available to anyone wishing to use, modify,
  10  * copy, or redistribute it subject to the terms and conditions of the GNU
  11  * Lesser General Public License, as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
  16  * for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this distribution; if not, write to:
  20  * Free Software Foundation, Inc.
  21  * 51 Franklin Street, Fifth Floor
  22  * Boston, MA  02110-1301  USA
  23  */
  24 package org.hibernate.proxy;
  25
  26 import java.io.Serializable;
  27
  28 import javax.naming.NamingException;
  29
  30 import org.hibernate.HibernateException;
  31 import org.hibernate.LazyInitializationException;
  32 import org.hibernate.Session;
  33 import org.hibernate.SessionException;
  34 import org.hibernate.TransientObjectException;
  35 import org.hibernate.engine.spi.EntityKey;
  36 import org.hibernate.engine.spi.SessionFactoryImplementor;
  37 import org.hibernate.engine.spi.SessionImplementor;
  38 import org.hibernate.internal.SessionFactoryRegistry;
  39 import org.hibernate.persister.entity.EntityPersister;
  40 import org.jboss.logging.Logger;
  41 import org.springframework.beans.factory.annotation.Autowire;
  42 import org.springframework.beans.factory.annotation.Configurable;
  43 import org.springframework.stereotype.Component;
  44
  45 import eu.etaxonomy.cdm.api.application.ICdmApplicationConfiguration;
  46 import eu.etaxonomy.cdm.api.service.ICommonService;
  47 import eu.etaxonomy.cdm.model.common.CdmBase;
  48
  49 /**
  50  * Convenience base class for lazy initialization handlers.  Centralizes the basic plumbing of doing lazy
  51  * initialization freeing subclasses to acts as essentially adapters to their intended entity mode and/or
  52  * proxy generation strategy.
  53  *
  54  * @author Gavin King
  55  */
  56 @Component
  57 @Configurable(dependencyCheck = true,autowire = Autowire.BY_TYPE)
  58 public abstract class AbstractLazyInitializer implements LazyInitializer {
  59         private static final Logger log = Logger.getLogger( AbstractLazyInitializer.class );
  60
  61         private String entityName;
  62         private Serializable id;
  63         private Object target;
  64         private boolean initialized;
  65         private boolean readOnly;
  66         private boolean unwrap;
  67         private transient SessionImplementor session;
  68         private Boolean readOnlyBeforeAttachedToSession;
  69
  70         private String sessionFactoryUuid;
  71         private boolean specjLazyLoad = false;
  72
  73         /**
  74          * For serialization from the non-pojo initializers (HHH-3309)
  75          */
  76         protected AbstractLazyInitializer() {
  77         }
  78
  79         /**
  80          * Main constructor.
  81          *
  82          * @param entityName The name of the entity being proxied.
  83          * @param id The identifier of the entity being proxied.
  84          * @param session The session owning the proxy.
  85          */
  86         protected AbstractLazyInitializer(String entityName, Serializable id, SessionImplementor session) {
  87                 this.entityName = entityName;
  88                 this.id = id;
  89                 // initialize other fields depending on session state
  90                 if ( session == null ) {
  91                         unsetSession();
  92                 }
  93                 else {
  94                         setSession( session );
  95                 }
  96         }
  97
  98         @Override
  99         public final String getEntityName() {
 100                 return entityName;
 101         }
 102
 103         @Override
 104         public final Serializable getIdentifier() {
 105                 return id;
 106         }
 107
 108         @Override
 109         public final void setIdentifier(Serializable id) {
 110                 this.id = id;
 111         }
 112
 113         @Override
 114         public final boolean isUninitialized() {
 115                 return !initialized;
 116         }
 117
 118         @Override
 119         public final SessionImplementor getSession() {
 120                 return session;
 121         }
 122
 123         @Override
 124         public final void setSession(SessionImplementor s) throws HibernateException {
 125                 if ( s != session ) {
 126                         // check for s == null first, since it is least expensive
 127                         if ( s == null ) {
 128                                 unsetSession();
 129                         }
 130                         else if ( isConnectedToSession() ) {
 131                                 //TODO: perhaps this should be some other RuntimeException...
 132                                 throw new HibernateException( "illegally attempted to associate a proxy with two open Sessions" );
 133                         }
 134                         else {
 135                                 // s != null
 136                                 session = s;
 137                                 if ( readOnlyBeforeAttachedToSession == null ) {
 138                                         // use the default read-only/modifiable setting
 139                                         final EntityPersister persister = s.getFactory().getEntityPersister( entityName );
 140                                         setReadOnly( s.getPersistenceContext().isDefaultReadOnly() || !persister.isMutable() );
 141                                 }
 142                                 else {
 143                                         // use the read-only/modifiable setting indicated during deserialization
 144                                         setReadOnly( readOnlyBeforeAttachedToSession.booleanValue() );
 145                                         readOnlyBeforeAttachedToSession = null;
 146                                 }
 147                         }
 148                 }
 149         }
 150
 151         private static EntityKey generateEntityKeyOrNull(Serializable id, SessionImplementor s, String entityName) {
 152                 if ( id == null || s == null || entityName == null ) {
 153                         return null;
 154                 }
 155                 return s.generateEntityKey( id, s.getFactory().getEntityPersister( entityName ) );
 156         }
 157
 158         @Override
 159         public final void unsetSession() {
 160                 prepareForPossibleSpecialSpecjInitialization();
 161                 session = null;
 162                 readOnly = false;
 163                 readOnlyBeforeAttachedToSession = null;
 164         }
 165
 166         @Override
 167         public final void initialize() throws HibernateException {
 168                 // In remoting we are sure that session is null
 169                 // both when using property paths and switching off conversations
 170                 if(session == null) {
 171                         remoteInitialize();
 172                 }
 173                 if ( !initialized ) {
 174                         if ( specjLazyLoad ) {
 175                                 specialSpecjInitialization();
 176                         }
 177                         else if ( session == null ) {
 178                                 throw new LazyInitializationException( "could not initialize proxy - no Session" );
 179                         }
 180                         else if ( !session.isOpen() ) {
 181                                 throw new LazyInitializationException( "could not initialize proxy - the owning Session was closed" );
 182                         }
 183                         else if ( !session.isConnected() ) {
 184                                 throw new LazyInitializationException( "could not initialize proxy - the owning Session is disconnected" );
 185                         }
 186                         else {
 187                                 target = session.immediateLoad( entityName, id );
 188                                 initialized = true;
 189                                 checkTargetState();
 190                         }
 191                 }
 192                 else {
 193                         checkTargetState();
 194                 }
 195         }
 196
 197         protected void specialSpecjInitialization() {
 198                 if ( session == null ) {
 199                         //we have a detached collection thats set to null, reattach
 200                         if ( sessionFactoryUuid == null ) {
 201                                 throw new LazyInitializationException( "could not initialize proxy - no Session" );
 202                         }
 203                         try {
 204                                 SessionFactoryImplementor sf = (SessionFactoryImplementor)
 205                                                 SessionFactoryRegistry.INSTANCE.getSessionFactory( sessionFactoryUuid );
 206                                 SessionImplementor session = (SessionImplementor) sf.openSession();
 207
 208                                 // TODO: On the next major release, add an
 209                                 // 'isJTA' or 'getTransactionFactory' method to Session.
 210                                 boolean isJTA = session.getTransactionCoordinator()
 211                                                 .getTransactionContext().getTransactionEnvironment()
 212                                                 .getTransactionFactory()
 213                                                 .compatibleWithJtaSynchronization();
 214
 215                                 if ( !isJTA ) {
 216                                         // Explicitly handle the transactions only if we're not in
 217                                         // a JTA environment.  A lazy loading temporary session can
 218                                         // be created even if a current session and transaction are
 219                                         // open (ex: session.clear() was used).  We must prevent
 220                                         // multiple transactions.
 221                                         ( ( Session) session ).beginTransaction();
 222                                 }
 223
 224                                 try {
 225                                         target = session.immediateLoad( entityName, id );
 226                                 }
 227                                 finally {
 228                                         // make sure the just opened temp session gets closed!
 229                                         try {
 230                                                 if ( !isJTA ) {
 231                                                         ( ( Session) session ).getTransaction().commit();
 232                                                 }
 233                                                 ( (Session) session ).close();
 234                                         }
 235                                         catch (Exception e) {
 236                                                 log.warn( "Unable to close temporary session used to load lazy proxy associated to no session" );
 237                                         }
 238                                 }
 239                                 initialized = true;
 240                                 checkTargetState();
 241                         }
 242                         catch (Exception e) {
 243                                 e.printStackTrace();
 244                                 throw new LazyInitializationException( e.getMessage() );
 245                         }
 246                 }
 247                 else if ( session.isOpen() && session.isConnected() ) {
 248                         target = session.immediateLoad( entityName, id );
 249                         initialized = true;
 250                         checkTargetState();
 251                 }
 252                 else {
 253                         throw new LazyInitializationException( "could not initialize proxy - Session was closed or disced" );
 254                 }
 255         }
 256
 257         protected void prepareForPossibleSpecialSpecjInitialization() {
 258                 if ( session != null ) {
 259                         specjLazyLoad = session.getFactory().getSettings().isInitializeLazyStateOutsideTransactionsEnabled();
 260
 261                         if ( specjLazyLoad && sessionFactoryUuid == null ) {
 262                                 try {
 263                                         sessionFactoryUuid = (String) session.getFactory().getReference().get( "uuid" ).getContent();
 264                                 }
 265                                 catch (NamingException e) {
 266                                         //not much we can do if this fails...
 267                                 }
 268                         }
 269                 }
 270         }
 271
 272         private void checkTargetState() {
 273                 if ( !unwrap ) {
 274                         if ( target == null ) {
 275                                 getSession().getFactory().getEntityNotFoundDelegate().handleEntityNotFound( entityName, id );
 276                         }
 277                 }
 278         }
 279
 280         /**
 281          * Getter for property 'connectedToSession'.
 282          *
 283          * @return Value for property 'connectedToSession'.
 284          */
 285         protected final boolean isConnectedToSession() {
 286                 return getProxyOrNull() != null;
 287         }
 288
 289         private Object getProxyOrNull() {
 290                 final EntityKey entityKey = generateEntityKeyOrNull( getIdentifier(), session, getEntityName() );
 291                 if ( entityKey != null && session != null && session.isOpen() ) {
 292                         return session.getPersistenceContext().getProxy( entityKey );
 293                 }
 294                 return null;
 295         }
 296
 297         @Override
 298         public final Object getImplementation() {
 299                 initialize();
 300                 return target;
 301         }
 302
 303         @Override
 304         public final void setImplementation(Object target) {
 305                 this.target = target;
 306                 initialized = true;
 307         }
 308
 309         @Override
 310         public final Object getImplementation(SessionImplementor s) throws HibernateException {
 311                 final EntityKey entityKey = generateEntityKeyOrNull( getIdentifier(), s, getEntityName() );
 312                 return (entityKey == null ? null : s.getPersistenceContext().getEntity( entityKey ));
 313         }
 314
 315         /**
 316          * Getter for property 'target'.
 317          * <p/>
 318          * Same as {@link #getImplementation()} except that this method will not force initialization.
 319          *
 320          * @return Value for property 'target'.
 321          */
 322         protected final Object getTarget() {
 323                 return target;
 324         }
 325
 326         @Override
 327         public final boolean isReadOnlySettingAvailable() {
 328                 return (session != null && !session.isClosed());
 329         }
 330
 331         private void errorIfReadOnlySettingNotAvailable() {
 332                 if ( session == null ) {
 333                         throw new TransientObjectException(
 334                                         "Proxy is detached (i.e, session is null). The read-only/modifiable setting is only accessible when the proxy is associated with an open session."
 335                         );
 336                 }
 337                 if ( session.isClosed() ) {
 338                         throw new SessionException(
 339                                         "Session is closed. The read-only/modifiable setting is only accessible when the proxy is associated with an open session."
 340                         );
 341                 }
 342         }
 343
 344         @Override
 345         public final boolean isReadOnly() {
 346                 errorIfReadOnlySettingNotAvailable();
 347                 return readOnly;
 348         }
 349
 350         @Override
 351         public final void setReadOnly(boolean readOnly) {
 352                 errorIfReadOnlySettingNotAvailable();
 353                 // only update if readOnly is different from current setting
 354                 if ( this.readOnly != readOnly ) {
 355                         final EntityPersister persister = session.getFactory().getEntityPersister( entityName );
 356                         if ( !persister.isMutable() && !readOnly ) {
 357                                 throw new IllegalStateException( "cannot make proxies for immutable entities modifiable" );
 358                         }
 359                         this.readOnly = readOnly;
 360                         if ( initialized ) {
 361                                 EntityKey key = generateEntityKeyOrNull( getIdentifier(), session, getEntityName() );
 362                                 if ( key != null && session.getPersistenceContext().containsEntity( key ) ) {
 363                                         session.getPersistenceContext().setReadOnly( target, readOnly );
 364                                 }
 365                         }
 366                 }
 367         }
 368
 369         /**
 370          * Get the read-only/modifiable setting that should be put in affect when it is
 371          * attached to a session.
 372          * <p/>
 373          * This method should only be called during serialization when read-only/modifiable setting
 374          * is not available (i.e., isReadOnlySettingAvailable() == false)
 375          *
 376          * @return null, if the default setting should be used;
 377          *         true, for read-only;
 378          *         false, for modifiable
 379          *
 380          * @throws IllegalStateException if isReadOnlySettingAvailable() == true
 381          */
 382         protected final Boolean isReadOnlyBeforeAttachedToSession() {
 383                 if ( isReadOnlySettingAvailable() ) {
 384                         throw new IllegalStateException(
 385                                         "Cannot call isReadOnlyBeforeAttachedToSession when isReadOnlySettingAvailable == true"
 386                         );
 387                 }
 388                 return readOnlyBeforeAttachedToSession;
 389         }
 390
 391         /**
 392          * Set the read-only/modifiable setting that should be put in affect when it is
 393          * attached to a session.
 394          * <p/>
 395          * This method should only be called during deserialization, before associating
 396          * the proxy with a session.
 397          *
 398          * @param readOnlyBeforeAttachedToSession, the read-only/modifiable setting to use when
 399          * associated with a session; null indicates that the default should be used.
 400          *
 401          * @throws IllegalStateException if isReadOnlySettingAvailable() == true
 402          */
 403         /* package-private */
 404         final void setReadOnlyBeforeAttachedToSession(Boolean readOnlyBeforeAttachedToSession) {
 405                 if ( isReadOnlySettingAvailable() ) {
 406                         throw new IllegalStateException(
 407                                         "Cannot call setReadOnlyBeforeAttachedToSession when isReadOnlySettingAvailable == true"
 408                         );
 409                 }
 410                 this.readOnlyBeforeAttachedToSession = readOnlyBeforeAttachedToSession;
 411         }
 412
 413         @Override
 414         public boolean isUnwrap() {
 415                 return unwrap;
 416         }
 417
 418         @Override
 419         public void setUnwrap(boolean unwrap) {
 420                 this.unwrap = unwrap;
 421         }
 422
 423         /** Below is section of code which makes remote service calls */
 424
 425         private static ICdmApplicationConfiguration configuration;
 426
 427         public static void setConfiguration(ICdmApplicationConfiguration conf) {
 428                 configuration = conf;
 429         }
 430
 431
 432         private void remoteInitialize() {
 433
 434                 if(!initialized) {
 435                         int classid = ((Integer)getIdentifier()).intValue();
 436                         System.out.print("--> Remote Lazy Initializing" + getEntityName() + " with id " + classid);
 437                         Class clazz;
 438                         try {
 439                                 clazz = (Class<? extends CdmBase>) Class.forName(getEntityName());
 440                         } catch (ClassNotFoundException e) {
 441                                 throw new HibernateException("Class for " + getEntityName() + " not found", e);
 442                         }
 443                         if(configuration == null) {
 444                                 throw new HibernateException("CdmApplicationRemoteConfiguration not initialized (null)");
 445                         }
 446                         ICommonService commonService = configuration.getCommonService();
 447                         if(commonService == null) {
 448                                 throw new HibernateException("commonService not initialized (null)");
 449                         }
 450
 451                         CdmBase cdmBase = CdmBase.deproxy(commonService.find(clazz,classid),clazz);
 452                         setImplementation(cdmBase);
 453                         System.out.println("....Done");
 454                 }
 455         }
 456
 457
 458 }