Apache OpenJPA User's Guide Apache OpenJPA User's Guide 1.Introduction ............................................................................................................................................. 1 1.OpenJPA......................................................................................................................................... 3 1.1.AboutThisDocument ............................................................................................................. 3 2.JavaPersistenceAPI ................................................................................................................................. 4 1.Introduction ..................................................................................................................................... 9 1.1.IntendedAudience.................................................................................................................. 9 1.2.LightweightPersistence ........................................................................................................... 9 2.WhyJPA? ......................................................................................................................................10 3.JavaPersistenceAPIArchitecture .......................................................................................................12 3.1.JPAExceptions.....................................................................................................................13 4.Entity ............................................................................................................................................15 4.1.RestrictionsonPersistentClasses .............................................................................................16 4.1.1.DefaultorNo-ArgConstructor ......................................................................................16 4.1.2.Final ........................................................................................................................16 4.1.3.IdentityFields ............................................................................................................16 4.1.4.VersionField .............................................................................................................16 4.1.5.Inheritance ................................................................................................................17 4.1.6.PersistentFields .........................................................................................................17 4.1.7.Conclusions ...............................................................................................................18 4.2.EntityIdentity ......................................................................................................................18 4.2.1.IdentityClass .............................................................................................................19 4.2.1.1.IdentityHierarchies ..........................................................................................20 4.3.LifecycleCallbacks ...............................................................................................................21 4.3.1.CallbackMethods .......................................................................................................21 4.3.2.UsingCallbackMethods ..............................................................................................22 4.3.3.UsingEntityListeners .................................................................................................22 4.3.4.EntityListenersHierarchy ............................................................................................23 4.4.Conclusions .........................................................................................................................24 5.Metadata ........................................................................................................................................25 5.1.ClassMetadata .....................................................................................................................26 5.1.1.Entity .......................................................................................................................26 5.1.2.IdClass.....................................................................................................................27 5.1.3.MappedSuperclass .....................................................................................................27 5.1.4.Embeddable ...............................................................................................................27 5.1.5.EntityListeners ...........................................................................................................28 5.1.6.Example ...................................................................................................................28 5.2.FieldandPropertyMetadata ....................................................................................................29 5.2.1.Transient ...................................................................................................................30 5.2.2.Id.............................................................................................................................31 5.2.3.GeneratedValue .........................................................................................................31 5.2.4.EmbeddedId .............................................................................................................32 5.2.5.Version .....................................................................................................................32 5.2.6.Basic ........................................................................................................................32 5.2.6.1.FetchType ......................................................................................................33 5.2.7.Embedded .................................................................................................................33 5.2.8.ManyToOne.............................................................................................................34 5.2.8.1.CascadeType ..................................................................................................34 5.2.9.OneToMany.............................................................................................................35 5.2.9.1.BidirectionalRelations ......................................................................................36 5.2.10.OneToOne .............................................................................................................37 5.2.11.ManyToMany .........................................................................................................37 5.2.12.OrderBy .................................................................................................................38 5.2.13.MapKey .................................................................................................................38 5.2.14.PersistentFieldDefaults .............................................................................................38 5.3.XMLSchema .......................................................................................................................39 5.4.Conclusion...........................................................................................................................55 6.Persistence .....................................................................................................................................60 6.1.persistence.xml .....................................................................................................................60 iv ApacheOpenJPAUser'sGuide 6.2.Non-EEUse .........................................................................................................................62 7.EntityManagerFactory ......................................................................................................................63 7.1.ObtaininganEntityManagerFactory..........................................................................................63 7.2.ObtainingEntityManagers ......................................................................................................63 7.3.PersistenceContext ...............................................................................................................64 7.3.1.TransactionPersistenceContext ....................................................................................64 7.3.2.ExtendedPersistenceContext........................................................................................65 7.4.ClosingtheEntityManagerFactory............................................................................................66 8.EntityManager ................................................................................................................................67 8.1.TransactionAssociation..........................................................................................................67 8.2.EntityLifecycleManagement ..................................................................................................68 8.3.LifecycleExamples ...............................................................................................................71 8.4.EntityIdentityManagement ....................................................................................................73 8.5.CacheManagement ...............................................................................................................73 8.6.QueryFactory ......................................................................................................................74 8.7.Closing ...............................................................................................................................75 9.Transaction.....................................................................................................................................76 9.1.TransactionTypes .................................................................................................................76 9.2.TheEntityTransactionInterface ...............................................................................................77 10.JPAQuery ....................................................................................................................................79 10.1.JPQLAPI ..........................................................................................................................79 10.1.1.QueryBasics ............................................................................................................79 10.1.2.RelationTraversal .....................................................................................................82 10.1.3.FetchJoins...............................................................................................................83 10.1.4.JPQLFunctions ........................................................................................................83 10.1.5.PolymorphicQueries .................................................................................................85 10.1.6.QueryParameters ......................................................................................................85 10.1.7.QueryHints .............................................................................................................86 10.1.7.1.LockingHints ................................................................................................86 10.1.7.2.ResultSetSizeHint ........................................................................................87 10.1.7.3.IsolationLevelHint ........................................................................................87 10.1.7.4.OtherFetchplanHints......................................................................................87 10.1.7.5.OracleQueryHints .........................................................................................87 10.1.7.6.NamedQueryHints ........................................................................................87 10.1.8.Ordering..................................................................................................................88 10.1.9.Aggregates ..............................................................................................................88 10.1.10.NamedQueries .......................................................................................................88 10.1.11.DeleteByQuery .....................................................................................................89 10.1.12.UpdateByQuery ....................................................................................................89 10.2.JPQLLanguageReference ....................................................................................................90 10.2.1.JPQLStatementTypes ...............................................................................................90 10.2.1.1.JPQLSelectStatement ....................................................................................90 10.2.1.2.JPQLUpdateandDeleteStatements ..................................................................91 10.2.2.JPQLAbstractSchemaTypesandQueryDomains ..........................................................91 10.2.2.1.JPQLEntityNaming .......................................................................................91 10.2.2.2.JPQLSchemaExample....................................................................................91 10.2.3.JPQLFROMClauseandNavigationalDeclarations.........................................................92 10.2.3.1.JPQLFROMIdentifiers ...................................................................................93 10.2.3.2.JPQLIdentificationVariables ...........................................................................95 10.2.3.3.JPQLRangeDeclarations.................................................................................95 10.2.3.4.JPQLPathExpressions ....................................................................................95 10.2.3.5.JPQLJoins ....................................................................................................96 10.2.3.5.1.JPQLInnerJoins(RelationshipJoins) ......................................................96 10.2.3.5.2.JPQLOuterJoins .................................................................................97 10.2.3.5.3.JPQLFetchJoins .................................................................................97 10.2.3.6.JPQLCollectionMemberDeclarations ...............................................................98 10.2.3.7.JPQLPolymorphism .......................................................................................98 10.2.4.JPQLWHEREClause ...............................................................................................99 10.2.5.JPQLConditionalExpressions.....................................................................................99 v ApacheOpenJPAUser'sGuide 10.2.5.1.JPQLLiterals.................................................................................................99 10.2.5.2.JPQLIdentificationVariables ...........................................................................99 10.2.5.3.JPQLPathExpressions ....................................................................................99 10.2.5.4.JPQLInputParameters ..................................................................................100 10.2.5.4.1.JPQLPositionalParameters .................................................................100 10.2.5.4.2.JPQLNamedParameters .....................................................................100 10.2.5.5.JPQLConditionalExpressionComposition .......................................................100 10.2.5.6.JPQLOperatorsandOperatorPrecedence .........................................................100 10.2.5.7.JPQLBetweenExpressions ............................................................................101 10.2.5.8.JPQLInExpressions .....................................................................................102 10.2.5.9.JPQLLikeExpressions ..................................................................................102 10.2.5.10.JPQLNullComparisonExpressions ...............................................................103 10.2.5.11.JPQLEmptyCollectionComparisonExpressions .............................................103 10.2.5.12.JPQLCollectionMemberExpressions ............................................................103 10.2.5.13.JPQLExistsExpressions ..............................................................................104 10.2.5.14.JPQLAllorAnyExpressions ........................................................................104 10.2.5.15.JPQLSubqueries ........................................................................................104 10.2.5.16.JPQLFunctionalExpressions ........................................................................105 10.2.5.16.1.JPQLStringFunctions ......................................................................105 10.2.5.16.2.JPQLArithmeticFunctions ................................................................106 10.2.5.16.3.JPQLDatetimeFunctions ..................................................................106 10.2.6.JPQLGROUPBY,HAVING ....................................................................................106 10.2.7.JPQLSELECTClause .............................................................................................107 10.2.7.1.JPQLResultTypeoftheSELECTClause .........................................................107 10.2.7.2.JPQLConstructorExpressions ........................................................................108 10.2.7.3.JPQLNullValuesintheQueryResult ..............................................................108 10.2.7.4.JPQLAggregateFunctions .............................................................................108 10.2.7.4.1.JPQLAggregateExamples ..................................................................109 10.2.8.JPQLORDERBYClause.........................................................................................109 10.2.9.JPQLBulkUpdateandDelete ...................................................................................109 10.2.10.JPQLNullValues..................................................................................................110 10.2.11.JPQLEqualityandComparisonSemantics .................................................................111 10.2.12.JPQLBNF ...........................................................................................................111 11.SQLQueries ...............................................................................................................................115 11.1.CreatingSQLQueries ........................................................................................................115 11.2.RetrievingPersistentObjectswithSQL .................................................................................115 12.MappingMetadata .......................................................................................................................117 12.1.Table...............................................................................................................................117 12.2.UniqueConstraints ............................................................................................................120 12.3.Column ...........................................................................................................................121 12.4.IdentityMapping ...............................................................................................................121 12.5.Generators........................................................................................................................124 12.5.1.SequenceGenerator .................................................................................................124 12.5.2.TableGenerator .......................................................................................................125 12.5.3.Example ................................................................................................................126 12.6.Inheritance .......................................................................................................................127 12.6.1.SingleTable ...........................................................................................................128 12.6.1.1.Advantages .................................................................................................129 12.6.1.2.Disadvantages ..............................................................................................129 12.6.2.Joined ...................................................................................................................129 12.6.2.1.Advantages .................................................................................................131 12.6.2.2.Disadvantages ..............................................................................................131 12.6.3.TablePerClass .......................................................................................................131 12.6.3.1.Advantages .................................................................................................132 12.6.3.2.Disadvantages ..............................................................................................133 12.6.4.PuttingitAllTogether .............................................................................................133 12.7.Discriminator....................................................................................................................136 12.8.FieldMapping ..................................................................................................................140 12.8.1.BasicMapping .......................................................................................................140 vi ApacheOpenJPAUser'sGuide 12.8.1.1.LOBs .........................................................................................................140 12.8.1.2.Enumerated .................................................................................................141 12.8.1.3.TemporalTypes ...........................................................................................141 12.8.1.4.TheUpdatedMappings ..................................................................................141 12.8.2.SecondaryTables ....................................................................................................146 12.8.3.EmbeddedMapping.................................................................................................147 12.8.4.DirectRelations ......................................................................................................150 12.8.5.JoinTable ..............................................................................................................152 12.8.6.BidirectionalMapping .............................................................................................155 12.8.7.MapMapping .........................................................................................................155 12.9.TheCompleteMappings .....................................................................................................156 13.Conclusion .................................................................................................................................165 3.ReferenceGuide ....................................................................................................................................166 1.Introduction ..................................................................................................................................173 1.1.IntendedAudience...............................................................................................................173 2.Configuration................................................................................................................................174 2.1.Introduction .......................................................................................................................174 2.2.RuntimeConfiguration .........................................................................................................174 2.3.CommandLineConfiguration ...............................................................................................174 2.3.1.CodeFormatting.......................................................................................................175 2.4.PluginConfiguration............................................................................................................176 2.5.OpenJPAProperties .............................................................................................................177 2.5.1.openjpa.AutoClear ....................................................................................................177 2.5.2.openjpa.AutoDetach ..................................................................................................177 2.5.3.openjpa.BrokerFactory...............................................................................................177 2.5.4.openjpa.BrokerImpl ..................................................................................................178 2.5.5.openjpa.ClassResolver ...............................................................................................178 2.5.6.openjpa.Compatibility ...............................................................................................178 2.5.7.openjpa.ConnectionDriverName ..................................................................................178 2.5.8.openjpa.Connection2DriverName ................................................................................178 2.5.9.openjpa.ConnectionFactory ........................................................................................179 2.5.10.openjpa.ConnectionFactory2 .....................................................................................179 2.5.11.openjpa.ConnectionFactoryName ...............................................................................179 2.5.12.openjpa.ConnectionFactory2Name .............................................................................179 2.5.13.openjpa.ConnectionFactoryMode ...............................................................................180 2.5.14.openjpa.ConnectionFactoryProperties .........................................................................180 2.5.15.openjpa.ConnectionFactory2Properties........................................................................180 2.5.16.openjpa.ConnectionPassword ....................................................................................180 2.5.17.openjpa.Connection2Password ..................................................................................181 2.5.18.openjpa.ConnectionProperties ...................................................................................181 2.5.19.openjpa.Connection2Properties ..................................................................................181 2.5.20.openjpa.ConnectionURL ..........................................................................................181 2.5.21.openjpa.Connection2URL.........................................................................................182 2.5.22.openjpa.ConnectionUserName...................................................................................182 2.5.23.openjpa.Connection2UserName .................................................................................182 2.5.24.openjpa.ConnectionRetainMode ................................................................................182 2.5.25.openjpa.DataCache..................................................................................................182 2.5.26.openjpa.DataCacheManager ......................................................................................183 2.5.27.openjpa.DataCacheTimeout ......................................................................................183 2.5.28.openjpa.DetachState ................................................................................................183 2.5.29.openjpa.DynamicDataStructs.....................................................................................183 2.5.30.openjpa.FetchBatchSize ...........................................................................................184 2.5.31.openjpa.FetchGroups ...............................................................................................184 2.5.32.openjpa.FlushBeforeQueries .....................................................................................184 2.5.33.openjpa.IgnoreChanges ............................................................................................184 2.5.34.openjpa.Id..............................................................................................................185 2.5.35.openjpa.InverseManager...........................................................................................185 2.5.36.openjpa.LockManager..............................................................................................185 2.5.37.openjpa.LockTimeout ..............................................................................................185 vii ApacheOpenJPAUser'sGuide 2.5.38.openjpa.Log ...........................................................................................................186 2.5.39.openjpa.ManagedRuntime ........................................................................................186 2.5.40.openjpa.Mapping ....................................................................................................186 2.5.41.openjpa.MaxFetchDepth...........................................................................................186 2.5.42.openjpa.MetaDataFactory .........................................................................................187 2.5.43.openjpa.Multithreaded .............................................................................................187 2.5.44.openjpa.Optimistic ..................................................................................................187 2.5.45.openjpa.OrphanedKeyAction.....................................................................................187 2.5.46.openjpa.NontransactionalRead...................................................................................188 2.5.47.openjpa.NontransactionalWrite ..................................................................................188 2.5.48.openjpa.ProxyManager ............................................................................................188 2.5.49.openjpa.QueryCache................................................................................................188 2.5.50.openjpa.QueryCompilationCache ...............................................................................188 2.5.51.openjpa.ReadLockLevel ...........................................................................................189 2.5.52.openjpa.RemoteCommitProvider................................................................................189 2.5.53.openjpa.RestoreState ...............................................................................................189 2.5.54.openjpa.RetainState .................................................................................................189 2.5.55.openjpa.RetryClassRegistration .................................................................................190 2.5.56.openjpa.RuntimeUnenhancedClasses ..........................................................................190 2.5.57.openjpa.SavepointManager .......................................................................................190 2.5.58.openjpa.Sequence....................................................................................................191 2.5.59.openjpa.TransactionMode .........................................................................................191 2.5.60.openjpa.WriteLockLevel ..........................................................................................191 2.6.OpenJPAJDBCProperties ....................................................................................................191 2.6.1.openjpa.jdbc.ConnectionDecorators .............................................................................191 2.6.2.openjpa.jdbc.DBDictionary ........................................................................................192 2.6.3.openjpa.jdbc.DriverDataSource ...................................................................................192 2.6.4.openjpa.jdbc.EagerFetchMode ....................................................................................192 2.6.5.openjpa.jdbc.FetchDirection .......................................................................................192 2.6.6.openjpa.jdbc.JDBCListeners .......................................................................................193 2.6.7.openjpa.jdbc.LRSSize................................................................................................193 2.6.8.openjpa.jdbc.MappingDefaults ....................................................................................193 2.6.9.openjpa.jdbc.MappingFactory .....................................................................................193 2.6.10.openjpa.jdbc.QuerySQLCache ...................................................................................194 2.6.11.openjpa.jdbc.ResultSetType ......................................................................................194 2.6.12.openjpa.jdbc.Schema ...............................................................................................194 2.6.13.openjpa.jdbc.SchemaFactory .....................................................................................194 2.6.14.openjpa.jdbc.Schemas ..............................................................................................195 2.6.15.openjpa.jdbc.SQLFactory .........................................................................................195 2.6.16.openjpa.jdbc.SubclassFetchMode ...............................................................................195 2.6.17.openjpa.jdbc.SynchronizeMappings ............................................................................195 2.6.18.openjpa.jdbc.TransactionIsolation ..............................................................................196 2.6.19.openjpa.jdbc.UpdateManager ....................................................................................196 3.Logging .......................................................................................................................................197 3.1.LoggingChannels ...............................................................................................................197 3.2.OpenJPALogging ...............................................................................................................198 3.3.DisablingLogging ...............................................................................................................199 3.4.Log4J................................................................................................................................199 3.5.ApacheCommonsLogging ...................................................................................................199 3.5.1.JDK1.4java.util.logging............................................................................................199 3.6.CustomLog .......................................................................................................................200 4.JDBC ..........................................................................................................................................202 4.1.UsingtheOpenJPADataSource .............................................................................................202 4.2.UsingaThird-PartyDataSource .............................................................................................202 4.2.1.ManagedandXADataSources ....................................................................................203 4.3.RuntimeAccesstoDataSource ..............................................................................................204 4.4.DatabaseSupport ................................................................................................................205 4.4.1.DBDictionaryProperties ............................................................................................206 4.4.2.MySQLDictionaryProperties ......................................................................................213 viii ApacheOpenJPAUser'sGuide 4.4.3.OracleDictionaryProperties ........................................................................................214 4.5.SettingtheTransactionIsolation ............................................................................................214 4.6.SettingtheSQLJoinSyntax ..................................................................................................215 4.7.AccessingMultipleDatabases ...............................................................................................215 4.8.ConfiguringtheUseofJDBCConnections...............................................................................216 4.9.StatementBatching..............................................................................................................217 4.10.LargeResultSets...............................................................................................................218 4.11.DefaultSchema .................................................................................................................220 4.12.SchemaReflection .............................................................................................................220 4.12.1.SchemasList ..........................................................................................................221 4.12.2.SchemaFactory ......................................................................................................221 4.13.SchemaTool ....................................................................................................................222 4.14.XMLSchemaFormat .........................................................................................................224 5.PersistentClasses...........................................................................................................................227 5.1.PersistentClassList .............................................................................................................227 5.2.Enhancement ......................................................................................................................227 5.2.1.EnhancingatBuildTime ............................................................................................228 5.2.2.EnhancingJPAEntitiesonDeployment ........................................................................229 5.2.3.EnhancingatRuntime................................................................................................229 5.2.4.OmittingtheOpenJPAenhancer ..................................................................................230 5.3.ManagedInterfaces .............................................................................................................231 5.4.ObjectIdentity ....................................................................................................................231 5.4.1.DatastoreIdentity .....................................................................................................231 5.4.2.EntitiesasIdentityFields ...........................................................................................232 5.4.3.ApplicationIdentityTool ...........................................................................................233 5.4.4.Autoassign/IdentityStrategyCaveats ..........................................................................234 5.5.ManagedInverses ...............................................................................................................234 5.6.PersistentFields ..................................................................................................................236 5.6.1.RestoringState .........................................................................................................236 5.6.2.TypingandOrdering .................................................................................................236 5.6.3.CalendarFieldsandTimeZones...................................................................................236 5.6.4.Proxies ...................................................................................................................237 5.6.4.1.SmartProxies ................................................................................................237 5.6.4.2.LargeResultSetProxies ..................................................................................237 5.6.4.3.CustomProxies..............................................................................................238 5.6.5.Externalization .........................................................................................................239 5.6.5.1.ExternalValues .............................................................................................242 5.7.FetchGroups ......................................................................................................................242 5.7.1.CustomFetchGroups ................................................................................................242 5.7.2.CustomFetchGroupConfiguration ..............................................................................244 5.7.3.Per-fieldFetchConfiguration ......................................................................................245 5.7.4.ImplementationNotes................................................................................................245 5.8.EagerFetching....................................................................................................................246 5.8.1.ConfiguringEagerFetching ........................................................................................247 5.8.2.EagerFetchingConsiderationsandLimitations ..............................................................248 6.Metadata ......................................................................................................................................249 6.1.MetadataFactory ................................................................................................................249 6.2.AdditionalJPAMetadata ......................................................................................................250 6.2.1.DatastoreIdentity .....................................................................................................250 6.2.2.SurrogateVersion .....................................................................................................250 6.2.3.PersistentFieldValues...............................................................................................250 6.2.4.PersistentCollectionFields.........................................................................................250 6.2.5.PersistentMapFields ................................................................................................251 6.3.MetadataExtensions ............................................................................................................251 6.3.1.ClassExtensions.......................................................................................................251 6.3.1.1.FetchGroups .................................................................................................251 6.3.1.2.DataCache ...................................................................................................252 6.3.1.3.DetachedState ...............................................................................................252 6.3.2.FieldExtensions .......................................................................................................252 ix ApacheOpenJPAUser'sGuide 6.3.2.1.Dependent ....................................................................................................252 6.3.2.2.LoadFetchGroup ..........................................................................................253 6.3.2.3.LRS .............................................................................................................253 6.3.2.4.Inverse-Logical ..............................................................................................253 6.3.2.5.Read-Only ....................................................................................................253 6.3.2.6.Type ............................................................................................................253 6.3.2.7.Externalizer...................................................................................................254 6.3.2.8.Factory.........................................................................................................254 6.3.2.9.ExternalValues .............................................................................................254 6.3.3.Example .................................................................................................................254 7.Mapping ......................................................................................................................................255 7.1.ForwardMapping ................................................................................................................255 7.1.1.UsingtheMappingTool ............................................................................................256 7.1.2.GeneratingDDLSQL ................................................................................................257 7.1.3.RuntimeForwardMapping .........................................................................................257 7.2.ReverseMapping ................................................................................................................258 7.2.1.CustomizingReverseMapping ....................................................................................260 7.3.Meet-in-the-MiddleMapping ................................................................................................262 7.4.MappingDefaults ................................................................................................................262 7.5.MappingFactory .................................................................................................................264 7.6.Non-StandardJoins .............................................................................................................265 7.7.AdditionalJPAMappings .....................................................................................................267 7.7.1.DatastoreIdentityMapping ........................................................................................267 7.7.2.SurrogateVersionMapping ........................................................................................267 7.7.3.Multi-ColumnMappings ............................................................................................268 7.7.4.JoinColumnAttributeTargets.....................................................................................268 7.7.5.EmbeddedMapping ..................................................................................................268 7.7.6.Collections ..............................................................................................................270 7.7.6.1.ContainerTable .............................................................................................270 7.7.6.2.ElementJoinColumns ....................................................................................270 7.7.6.3.OrderColumn ...............................................................................................270 7.7.7.One-SidedOne-ManyMapping ...................................................................................271 7.7.8.Maps ......................................................................................................................272 7.7.9.IndexesandConstraints .............................................................................................272 7.7.9.1.Indexes ........................................................................................................272 7.7.9.2.ForeignKeys .................................................................................................272 7.7.9.3.UniqueConstraints .........................................................................................273 7.7.10.XMLColumnMapping ............................................................................................273 7.7.11.StreamLOBSupport ...............................................................................................277 7.8.KeyColumns .....................................................................................................................277 7.9.KeyJoinColumns ...............................................................................................................277 7.10.KeyEmbeddedMapping.....................................................................................................277 7.11.Examples .........................................................................................................................278 7.12.MappingLimitations ..........................................................................................................278 7.12.1.TablePerClass .......................................................................................................279 7.13.MappingExtensions...........................................................................................................279 7.13.1.ClassExtensions .....................................................................................................279 7.13.1.1.SubclassFetchMode.....................................................................................279 7.13.1.2.Strategy ......................................................................................................279 7.13.1.3.DiscriminatorStrategy ...................................................................................279 7.13.1.4.VersionStrategy ...........................................................................................279 7.13.2.FieldExtensions .....................................................................................................280 7.13.2.1.EagerFetchMode.........................................................................................280 7.13.2.2.Nonpolymorphic ..........................................................................................280 7.13.2.3.ClassCriteria ...............................................................................................280 7.13.2.4.Strategy ......................................................................................................280 7.14.CustomMappings..............................................................................................................281 7.14.1.CustomClassMapping ............................................................................................281 7.14.2.CustomDiscriminatorandVersionStrategies ...............................................................281 x