/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
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 * indicated by the @author tags or express copyright attribution
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
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package org.hibernate.metamodel.source.annotations;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.persistence.AccessType;

import org.hibernate.AnnotationException;
import org.hibernate.internal.util.collections.CollectionHelper;
import org.hibernate.metamodel.binding.InheritanceType;
import org.hibernate.metamodel.source.annotations.entity.EntityClass;
import org.hibernate.metamodel.source.annotations.entity.RootEntitySourceImpl;
import org.hibernate.metamodel.source.annotations.entity.SubclassEntitySourceImpl;
import org.hibernate.metamodel.source.binder.EntityHierarchy;
import org.hibernate.metamodel.source.binder.EntitySource;
import org.hibernate.metamodel.source.binder.SubclassEntitySource;

import org.jboss.jandex.AnnotationInstance;
import org.jboss.jandex.ClassInfo;
import org.jboss.jandex.DotName;
import org.jboss.jandex.FieldInfo;
import org.jboss.jandex.Index;
import org.jboss.jandex.MethodInfo;

Given a (jandex) annotation index build processes all classes with JPA relevant annotations and pre-orders JPA entities respectively their inheritance hierarchy.
Author:Hardy Ferentschik
/** * Given a (jandex) annotation index build processes all classes with JPA relevant annotations and pre-orders * JPA entities respectively their inheritance hierarchy. * * @author Hardy Ferentschik */
public class EntityHierarchyBuilder { private static final DotName OBJECT = DotName.createSimple( Object.class.getName() );
Pre-processes the annotated entities from the index and create a set of entity hierarchies which can be bound to the metamodel.
Params:
  • bindingContext – The binding context, giving access to needed services and information
Returns:a set of EntityHierarchy instances.
/** * Pre-processes the annotated entities from the index and create a set of entity hierarchies which can be bound * to the metamodel. * * @param bindingContext The binding context, giving access to needed services and information * * @return a set of {@code EntityHierarchy} instances. */
public static Set<EntityHierarchy> createEntityHierarchies(AnnotationBindingContext bindingContext) { Set<EntityHierarchy> hierarchies = new HashSet<EntityHierarchy>(); List<DotName> processedEntities = new ArrayList<DotName>(); Map<DotName, List<ClassInfo>> classToDirectSubClassMap = new HashMap<DotName, List<ClassInfo>>(); Index index = bindingContext.getIndex(); for ( ClassInfo info : index.getKnownClasses() ) { if ( !isEntityClass( info ) ) { continue; } if ( processedEntities.contains( info.name() ) ) { continue; } ClassInfo rootClassInfo = findRootEntityClassInfo( index, info ); List<ClassInfo> rootClassWithAllSubclasses = new ArrayList<ClassInfo>(); // the root entity might have some mapped super classes which we have to take into consideration // for inheritance type and default access addMappedSuperclasses( index, rootClassInfo, rootClassWithAllSubclasses ); // collect the current root entity and all its subclasses processHierarchy( bindingContext, rootClassInfo, rootClassWithAllSubclasses, processedEntities, classToDirectSubClassMap ); AccessType defaultAccessType = determineDefaultAccessType( rootClassWithAllSubclasses ); InheritanceType hierarchyInheritanceType = determineInheritanceType( rootClassInfo, rootClassWithAllSubclasses ); // create the root entity source EntityClass rootEntityClass = new EntityClass( rootClassInfo, null, defaultAccessType, hierarchyInheritanceType, bindingContext ); RootEntitySourceImpl rootSource = new RootEntitySourceImpl( rootEntityClass ); addSubclassEntitySources( bindingContext, classToDirectSubClassMap, defaultAccessType, hierarchyInheritanceType, rootEntityClass, rootSource ); hierarchies.add( new EntityHierarchyImpl( rootSource, hierarchyInheritanceType ) ); } return hierarchies; } private static void addSubclassEntitySources(AnnotationBindingContext bindingContext, Map<DotName, List<ClassInfo>> classToDirectSubClassMap, AccessType defaultAccessType, InheritanceType hierarchyInheritanceType, EntityClass entityClass, EntitySource entitySource) { List<ClassInfo> subClassInfoList = classToDirectSubClassMap.get( DotName.createSimple( entitySource.getClassName() ) ); if ( subClassInfoList == null ) { return; } for ( ClassInfo subClassInfo : subClassInfoList ) { EntityClass subclassEntityClass = new EntityClass( subClassInfo, entityClass, defaultAccessType, hierarchyInheritanceType, bindingContext ); SubclassEntitySource subclassEntitySource = new SubclassEntitySourceImpl( subclassEntityClass ); entitySource.add( subclassEntitySource ); addSubclassEntitySources( bindingContext, classToDirectSubClassMap, defaultAccessType, hierarchyInheritanceType, subclassEntityClass, subclassEntitySource ); } }
Finds the root entity starting at the entity given by info. The root entity is not the highest superclass in a java type sense, but the highest superclass which is also an entity (annotated w/ @Entity.
Params:
  • index – the annotation repository
  • info – the class info representing an entity
Returns:Finds the root entity starting at the entity given by info
/** * Finds the root entity starting at the entity given by {@code info}. The root entity is not the highest superclass * in a java type sense, but the highest superclass which is also an entity (annotated w/ {@code @Entity}. * * @param index the annotation repository * @param info the class info representing an entity * * @return Finds the root entity starting at the entity given by {@code info} */
private static ClassInfo findRootEntityClassInfo(Index index, ClassInfo info) { ClassInfo rootEntity = info; DotName superName = info.superName(); ClassInfo tmpInfo; // walk up the hierarchy until java.lang.Object while ( !OBJECT.equals( superName ) ) { tmpInfo = index.getClassByName( superName ); if ( isEntityClass( tmpInfo ) ) { rootEntity = tmpInfo; } superName = tmpInfo.superName(); } return rootEntity; } private static void addMappedSuperclasses(Index index, ClassInfo info, List<ClassInfo> classInfoList) { DotName superName = info.superName(); ClassInfo tmpInfo; // walk up the hierarchy until java.lang.Object while ( !OBJECT.equals( superName ) ) { tmpInfo = index.getClassByName( superName ); if ( isMappedSuperclass( tmpInfo ) ) { classInfoList.add( tmpInfo ); } superName = tmpInfo.superName(); } }
This method does several things.
  • Collect all java subclasses (recursive) of classInfo in rootClassWithAllSubclasses.
  • Keeping track of all processed classed annotated with @Entity
  • Building up a map of class to direct subclass list
Params:
  • bindingContext – the binding context
  • classInfo – the current class info
  • rootClassWithAllSubclasses – used to collect all classes in the hierarchy starting at classInfo
  • processedEntities – Used to keep track of all processed entities
  • classToDirectSubclassMap – Create a map of class to direct subclass
/** * This method does several things. * <ul> * <li>Collect all java subclasses (recursive) of {@code classInfo} in {@code rootClassWithAllSubclasses}. </li> * <li>Keeping track of all processed classed annotated with {@code @Entity}</li> * <li>Building up a map of class to direct subclass list</li> * </ul> * * @param bindingContext the binding context * @param classInfo the current class info * @param rootClassWithAllSubclasses used to collect all classes in the hierarchy starting at {@code classInfo} * @param processedEntities Used to keep track of all processed entities * @param classToDirectSubclassMap Create a map of class to direct subclass */
private static void processHierarchy(AnnotationBindingContext bindingContext, ClassInfo classInfo, List<ClassInfo> rootClassWithAllSubclasses, List<DotName> processedEntities, Map<DotName, List<ClassInfo>> classToDirectSubclassMap) { processedEntities.add( classInfo.name() ); rootClassWithAllSubclasses.add( classInfo ); List<ClassInfo> subClasses = bindingContext.getIndex().getKnownDirectSubclasses( classInfo.name() ); // if there are no more subclasses we reached the leaf class. In order to properly resolve generics we // need to resolve the type information using this leaf class if ( subClasses.isEmpty() ) { bindingContext.resolveAllTypes( classInfo.name().toString() ); } for ( ClassInfo subClassInfo : subClasses ) { addSubClassToSubclassMap( classInfo.name(), subClassInfo, classToDirectSubclassMap ); processHierarchy( bindingContext, subClassInfo, rootClassWithAllSubclasses, processedEntities, classToDirectSubclassMap ); } } private static void addSubClassToSubclassMap(DotName name, ClassInfo subClassInfo, Map<DotName, List<ClassInfo>> classToDirectSubclassMap) { if ( classToDirectSubclassMap.containsKey( name ) ) { classToDirectSubclassMap.get( name ).add( subClassInfo ); } else { List<ClassInfo> subclassList = new ArrayList<ClassInfo>(); subclassList.add( subClassInfo ); classToDirectSubclassMap.put( name, subclassList ); } }
Checks whether the class info represents an entity.
Params:
  • info – the jandex class info
Returns:true if the class represented by info is annotated with @Entity, false otherwise.
/** * Checks whether the class info represents an entity. * * @param info the jandex class info * * @return {@code true} if the class represented by {@code info} is annotated with {@code @Entity}, {@code false} otherwise. */
private static boolean isEntityClass(ClassInfo info) { if ( info == null ) { return false; } // we are only interested in building the class hierarchies for @Entity AnnotationInstance jpaEntityAnnotation = JandexHelper.getSingleAnnotation( info, JPADotNames.ENTITY ); if ( jpaEntityAnnotation == null ) { return false; } // some sanity checks AnnotationInstance mappedSuperClassAnnotation = JandexHelper.getSingleAnnotation( info, JPADotNames.MAPPED_SUPERCLASS ); String className = info.toString(); assertNotEntityAndMappedSuperClass( jpaEntityAnnotation, mappedSuperClassAnnotation, className ); AnnotationInstance embeddableAnnotation = JandexHelper.getSingleAnnotation( info, JPADotNames.EMBEDDABLE ); assertNotEntityAndEmbeddable( jpaEntityAnnotation, embeddableAnnotation, className ); return true; }
Checks whether the class info represents a mapped superclass.
Params:
  • info – the jandex class info
Returns:true if the class represented by info is annotated with @MappedSuperclass, false otherwise.
/** * Checks whether the class info represents a mapped superclass. * * @param info the jandex class info * * @return {@code true} if the class represented by {@code info} is annotated with {@code @MappedSuperclass}, {@code false} otherwise. */
private static boolean isMappedSuperclass(ClassInfo info) { if ( info == null ) { return false; } // we are only interested in building the class hierarchies for @Entity AnnotationInstance mappedSuperclassAnnotation = JandexHelper.getSingleAnnotation( info, JPADotNames.MAPPED_SUPERCLASS ); return mappedSuperclassAnnotation != null; } private static void assertNotEntityAndMappedSuperClass(AnnotationInstance jpaEntityAnnotation, AnnotationInstance mappedSuperClassAnnotation, String className) { if ( jpaEntityAnnotation != null && mappedSuperClassAnnotation != null ) { throw new AnnotationException( "An entity cannot be annotated with both @Entity and @MappedSuperclass. " + className + " has both annotations." ); } } private static void assertNotEntityAndEmbeddable(AnnotationInstance jpaEntityAnnotation, AnnotationInstance embeddableAnnotation, String className) { if ( jpaEntityAnnotation != null && embeddableAnnotation != null ) { throw new AnnotationException( "An entity cannot be annotated with both @Entity and @Embeddable. " + className + " has both annotations." ); } }
Params:
  • classes – the classes in the hierarchy
Returns:Returns the default access type for the configured class hierarchy independent of explicit AccessType annotations. The default access type is determined by the placement of the annotations.
/** * @param classes the classes in the hierarchy * * @return Returns the default access type for the configured class hierarchy independent of explicit * {@code AccessType} annotations. The default access type is determined by the placement of the * annotations. */
private static AccessType determineDefaultAccessType(List<ClassInfo> classes) { AccessType accessTypeByEmbeddedIdPlacement = null; AccessType accessTypeByIdPlacement = null; for ( ClassInfo info : classes ) { List<AnnotationInstance> idAnnotations = info.annotations().get( JPADotNames.ID ); List<AnnotationInstance> embeddedIdAnnotations = info.annotations().get( JPADotNames.EMBEDDED_ID ); if ( CollectionHelper.isNotEmpty( embeddedIdAnnotations ) ) { accessTypeByEmbeddedIdPlacement = determineAccessTypeByIdPlacement( embeddedIdAnnotations ); } if ( CollectionHelper.isNotEmpty( idAnnotations ) ) { accessTypeByIdPlacement = determineAccessTypeByIdPlacement( idAnnotations ); } } if ( accessTypeByEmbeddedIdPlacement != null ) { return accessTypeByEmbeddedIdPlacement; } else if ( accessTypeByIdPlacement != null ) { return accessTypeByIdPlacement; } else { return throwIdNotFoundAnnotationException( classes ); } } private static AccessType determineAccessTypeByIdPlacement(List<AnnotationInstance> idAnnotations) { AccessType accessType = null; for ( AnnotationInstance annotation : idAnnotations ) { AccessType tmpAccessType; if ( annotation.target() instanceof FieldInfo ) { tmpAccessType = AccessType.FIELD; } else if ( annotation.target() instanceof MethodInfo ) { tmpAccessType = AccessType.PROPERTY; } else { throw new AnnotationException( "Invalid placement of @Id annotation" ); } if ( accessType == null ) { accessType = tmpAccessType; } else { if ( !accessType.equals( tmpAccessType ) ) { throw new AnnotationException( "Inconsistent placement of @Id annotation within hierarchy " ); } } } return accessType; } private static InheritanceType determineInheritanceType(ClassInfo rootClassInfo, List<ClassInfo> classes) { if(classes.size() == 1) { return InheritanceType.NO_INHERITANCE; } // if we have more than one entity class the default is SINGLE_TABLE InheritanceType inheritanceType = InheritanceType.SINGLE_TABLE; AnnotationInstance inheritanceAnnotation = JandexHelper.getSingleAnnotation( rootClassInfo, JPADotNames.INHERITANCE ); if ( inheritanceAnnotation != null ) { String enumName = inheritanceAnnotation.value( "strategy" ).asEnum(); javax.persistence.InheritanceType jpaInheritanceType = Enum.valueOf( javax.persistence.InheritanceType.class, enumName ); inheritanceType = InheritanceType.get( jpaInheritanceType ); } // sanity check that the is no other @Inheritance annotation in the hierarchy for ( ClassInfo info : classes ) { if ( rootClassInfo.equals( info ) ) { continue; } inheritanceAnnotation = JandexHelper.getSingleAnnotation( info, JPADotNames.INHERITANCE ); if ( inheritanceAnnotation != null ) { throw new AnnotationException( String.format( "The inheritance type for %s must be specified on the root entity %s", hierarchyListString( classes ), rootClassInfo.name().toString() ) ); } } return inheritanceType; } private static AccessType throwIdNotFoundAnnotationException(List<ClassInfo> classes) { StringBuilder builder = new StringBuilder(); builder.append( "Unable to determine identifier attribute for class hierarchy consisting of the classe(s) " ); builder.append( hierarchyListString( classes ) ); throw new AnnotationException( builder.toString() ); } private static String hierarchyListString(List<ClassInfo> classes) { StringBuilder builder = new StringBuilder(); builder.append( "[" ); int count = 0; for ( ClassInfo info : classes ) { builder.append( info.name().toString() ); if ( count < classes.size() - 1 ) { builder.append( ", " ); } count++; } builder.append( "]" ); return builder.toString(); } }