// $Id: CollectionType.java 14842 2008-07-01 21:49:14Z [email protected] $
package org.hibernate.type;
import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.dom4j.Element;
import org.dom4j.Node;
import org.hibernate.EntityMode;
import org.hibernate.Hibernate;
import org.hibernate.HibernateException;
import org.hibernate.MappingException;
import org.hibernate.collection.PersistentCollection;
import org.hibernate.engine.CollectionKey;
import org.hibernate.engine.EntityEntry;
import org.hibernate.engine.Mapping;
import org.hibernate.engine.PersistenceContext;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.persister.collection.QueryableCollection;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.persister.entity.Joinable;
import org.hibernate.proxy.HibernateProxy;
import org.hibernate.proxy.LazyInitializer;
import org.hibernate.util.ArrayHelper;
import org.hibernate.util.MarkerObject;
/**
* A type that handles Hibernate <tt>PersistentCollection</tt>s (including arrays).
*
* @author Gavin King
*/
public abstract class CollectionType extends AbstractType implements AssociationType {
private static final Object NOT_NULL_COLLECTION = new MarkerObject( "NOT NULL COLLECTION" );
public static final Object UNFETCHED_COLLECTION = new MarkerObject( "UNFETCHED COLLECTION" );
private final String role;
private final String foreignKeyPropertyName;
private final boolean isEmbeddedInXML;
public CollectionType(String role, String foreignKeyPropertyName, boolean isEmbeddedInXML) {
this.role = role;
this.foreignKeyPropertyName = foreignKeyPropertyName;
this.isEmbeddedInXML = isEmbeddedInXML;
}
public boolean isEmbeddedInXML() {
return isEmbeddedInXML;
}
public String getRole() {
return role;
}
public Object indexOf(Object collection, Object element) {
throw new UnsupportedOperationException( "generic collections don't have indexes" );
}
public boolean contains(Object collection, Object childObject, SessionImplementor session) {
// we do not have to worry about queued additions to uninitialized
// collections, since they can only occur for inverse collections!
Iterator elems = getElementsIterator( collection, session );
while ( elems.hasNext() ) {
Object element = elems.next();
// worrying about proxies is perhaps a little bit of overkill here...
if ( element instanceof HibernateProxy ) {
LazyInitializer li = ( (HibernateProxy) element ).getHibernateLazyInitializer();
if ( !li.isUninitialized() ) element = li.getImplementation();
}
if ( element == childObject ) return true;
}
return false;
}
public boolean isCollectionType() {
return true;
}
public final boolean isEqual(Object x, Object y, EntityMode entityMode) {
return x == y
|| ( x instanceof PersistentCollection && ( (PersistentCollection) x ).isWrapper( y ) )
|| ( y instanceof PersistentCollection && ( (PersistentCollection) y ).isWrapper( x ) );
}
public int compare(Object x, Object y, EntityMode entityMode) {
return 0; // collections cannot be compared
}
public int getHashCode(Object x, EntityMode entityMode) {
throw new UnsupportedOperationException( "cannot perform lookups on collections" );
}
/**
* Instantiate an uninitialized collection wrapper or holder. Callers MUST add the holder to the
* persistence context!
*
* @param session The session from which the request is originating.
* @param persister The underlying collection persister (metadata)
* @param key The owner key.
* @return The instantiated collection.
*/
public abstract PersistentCollection instantiate(SessionImplementor session, CollectionPersister persister, Serializable key);
public Object nullSafeGet(ResultSet rs, String name, SessionImplementor session, Object owner)
throws HibernateException, SQLException {
return nullSafeGet( rs, new String[] { name }, session, owner );
}
public Object nullSafeGet(ResultSet rs, String[] name, SessionImplementor session, Object owner)
throws HibernateException, SQLException {
return resolve( null, session, owner );
}
public final void nullSafeSet(PreparedStatement st, Object value, int index, boolean[] settable,
SessionImplementor session) throws HibernateException, SQLException {
//NOOP
}
public void nullSafeSet(PreparedStatement st, Object value, int index,
SessionImplementor session) throws HibernateException, SQLException {
}
public int[] sqlTypes(Mapping session) throws MappingException {
return ArrayHelper.EMPTY_INT_ARRAY;
}
public int getColumnSpan(Mapping session) throws MappingException {
return 0;
}
public String toLoggableString(Object value, SessionFactoryImplementor factory)
throws HibernateException {
if ( value == null ) {
return "null";
}
else if ( !Hibernate.isInitialized( value ) ) {
return "<uninitialized>";
}
else {
return renderLoggableString( value, factory );
}
}
protected String renderLoggableString(Object value, SessionFactoryImplementor factory) {
if ( Element.class.isInstance( value ) ) {
// for DOM4J "collections" only
// TODO: it would be better if this was done at the higher level by Printer
return ( ( Element ) value ).asXML();
}
else {
List list = new ArrayList();
Type elemType = getElementType( factory );
Iterator iter = getElementsIterator( value );
while ( iter.hasNext() ) {
list.add( elemType.toLoggableString( iter.next(), factory ) );
}
return list.toString();
}
}
public Object deepCopy(Object value, EntityMode entityMode, SessionFactoryImplementor factory)
throws HibernateException {
return value;
}
public String getName() {
return getReturnedClass().getName() + '(' + getRole() + ')';
}
/**
* Get an iterator over the element set of the collection, which may not yet be wrapped
*
* @param collection The collection to be iterated
* @param session The session from which the request is originating.
* @return The iterator.
*/
public Iterator getElementsIterator(Object collection, SessionImplementor session) {
if ( session.getEntityMode()==EntityMode.DOM4J ) {
final SessionFactoryImplementor factory = session.getFactory();
final CollectionPersister persister = factory.getCollectionPersister( getRole() );
final Type elementType = persister.getElementType();
List elements = ( (Element) collection ).elements( persister.getElementNodeName() );
ArrayList results = new ArrayList();
for ( int i=0; i<elements.size(); i++ ) {
Element value = (Element) elements.get(i);
results.add( elementType.fromXMLNode( value, factory ) );
}
return results.iterator();
}
else {
return getElementsIterator(collection);
}
}
/**
* Get an iterator over the element set of the collection in POJO mode
*
* @param collection The collection to be iterated
* @return The iterator.
*/
protected Iterator getElementsIterator(Object collection) {
return ( (Collection) collection ).iterator();
}
public boolean isMutable() {
return false;
}
public Serializable disassemble(Object value, SessionImplementor session, Object owner)
throws HibernateException {
//remember the uk value
//This solution would allow us to eliminate the owner arg to disassemble(), but
//what if the collection was null, and then later had elements added? seems unsafe
//session.getPersistenceContext().getCollectionEntry( (PersistentCollection) value ).getKey();
final Serializable key = getKeyOfOwner(owner, session);
if (key==null) {
return null;
}
else {
return getPersister(session)
.getKeyType()
.disassemble( key, session, owner );
}
}
public Object assemble(Serializable cached, SessionImplementor session, Object owner)
throws HibernateException {
//we must use the "remembered" uk value, since it is
//not available from the EntityEntry during assembly
if (cached==null) {
return null;
}
else {
final Serializable key = (Serializable) getPersister(session)
.getKeyType()
.assemble( cached, session, owner);
return resolveKey( key, session, owner );
}
}
/**
* Is the owning entity versioned?
*
* @param session The session from which the request is originating.
* @return True if the collection owner is versioned; false otherwise.
* @throws MappingException Indicates the underlying persister could not be located.
*/
private boolean isOwnerVersioned(SessionImplementor session) throws MappingException {
return getPersister( session ).getOwnerEntityPersister().isVersioned();
}
/**
* Get our underlying collection persister (using the session to access the
* factory).
*
* @param session The session from which the request is originating.
* @return The underlying collection persister
* @throws org.hibernate.MappingException Indicates the underlying persister could not be located.
*/
private CollectionPersister getPersister(SessionImplementor session) throws MappingException {
return session.getFactory().getCollectionPersister( role );
}
public boolean isDirty(Object old, Object current, SessionImplementor session)
throws HibernateException {
// collections don't dirty an unversioned parent entity
// TODO: I don't really like this implementation; it would be better if
// this was handled by searchForDirtyCollections()
return isOwnerVersioned( session ) && super.isDirty( old, current, session );
// return false;
}
public boolean isDirty(Object old, Object current, boolean[] checkable, SessionImplementor session)
throws HibernateException {
return isDirty(old, current, session);
}
/**
* Wrap the naked collection instance in a wrapper, or instantiate a
* holder. Callers <b>MUST</b> add the holder to the persistence context!
*
* @param session The session from which the request is originating.
* @param collection The bare collection to be wrapped.
* @return The wrapped collection.
*/
public abstract PersistentCollection wrap(SessionImplementor session, Object collection);
/**
* Note: return true because this type is castable to <tt>AssociationType</tt>. Not because
* all collections are associations.
*/
public boolean isAssociationType() {
return true;
}
public ForeignKeyDirection getForeignKeyDirection() {
return ForeignKeyDirection.FOREIGN_KEY_TO_PARENT;
}
/**
* Get the key value from the owning entity instance, usually the identifier, but might be some
* other unique key, in the case of property-ref
*
* @param owner The collection owner
* @param session The session from which the request is originating.
* @return The collection owner's key
*/
public Serializable getKeyOfOwner(Object owner, SessionImplementor session) {
EntityEntry entityEntry = session.getPersistenceContext().getEntry( owner );
if ( entityEntry == null ) return null; // This just handles a particular case of component
// projection, perhaps get rid of it and throw an exception
if ( foreignKeyPropertyName == null ) {
return entityEntry.getId();
}
else {
// TODO: at the point where we are resolving collection references, we don't
// know if the uk value has been resolved (depends if it was earlier or
// later in the mapping document) - now, we could try and use e.getStatus()
// to decide to semiResolve(), trouble is that initializeEntity() reuses
// the same array for resolved and hydrated values
Object id;
if ( entityEntry.getLoadedState() != null ) {
id = entityEntry.getLoadedValue( foreignKeyPropertyName );
}
else {
id = entityEntry.getPersister().getPropertyValue( owner, foreignKeyPropertyName, session.getEntityMode() );
}
// NOTE VERY HACKISH WORKAROUND!!
// TODO: Fix this so it will work for non-POJO entity mode
Type keyType = getPersister( session ).getKeyType();
if ( !keyType.getReturnedClass().isInstance( id ) ) {
id = (Serializable) keyType.semiResolve(
entityEntry.getLoadedValue( foreignKeyPropertyName ),
session,
owner
);
}
return (Serializable) id;
}
}
/**
* Get the id value from the owning entity key, usually the same as the key, but might be some
* other property, in the case of property-ref
*
* @param key The collection owner key
* @param session The session from which the request is originating.
* @return The collection owner's id, if it can be obtained from the key;
* otherwise, null is returned
*/
public Serializable getIdOfOwnerOrNull(Serializable key, SessionImplementor session) {
Serializable ownerId = null;
if ( foreignKeyPropertyName == null ) {
ownerId = key;
}
else {
Type keyType = getPersister( session ).getKeyType();
EntityPersister ownerPersister = getPersister( session ).getOwnerEntityPersister();
// TODO: Fix this so it will work for non-POJO entity mode
Class ownerMappedClass = ownerPersister.getMappedClass( session.getEntityMode() );
if ( ownerMappedClass.isAssignableFrom( keyType.getReturnedClass() ) &&
keyType.getReturnedClass().isInstance( key ) ) {
// the key is the owning entity itself, so get the ID from the key
ownerId = ownerPersister.getIdentifier( key, session.getEntityMode() );
}
else {
// TODO: check if key contains the owner ID
}
}
return ownerId;
}
public Object hydrate(ResultSet rs, String[] name, SessionImplementor session, Object owner) {
// can't just return null here, since that would
// cause an owning component to become null
return NOT_NULL_COLLECTION;
}
public Object resolve(Object value, SessionImplementor session, Object owner)
throws HibernateException {
return resolveKey( getKeyOfOwner( owner, session ), session, owner );
}
private Object resolveKey(Serializable key, SessionImplementor session, Object owner) {
// if (key==null) throw new AssertionFailure("owner identifier unknown when re-assembling
// collection reference");
return key == null ? null : // TODO: can this case really occur??
getCollection( key, session, owner );
}
public Object semiResolve(Object value, SessionImplementor session, Object owner)
throws HibernateException {
throw new UnsupportedOperationException(
"collection mappings may not form part of a property-ref" );
}
public boolean isArrayType() {
return false;
}
public boolean useLHSPrimaryKey() {
return foreignKeyPropertyName == null;
}
public String getRHSUniqueKeyPropertyName() {
return null;
}
public Joinable getAssociatedJoinable(SessionFactoryImplementor factory)
throws MappingException {
return (Joinable) factory.getCollectionPersister( role );
}
public boolean isModified(Object old, Object current, boolean[] checkable, SessionImplementor session) throws HibernateException {
return false;
}
public String getAssociatedEntityName(SessionFactoryImplementor factory)
throws MappingException {
try {
QueryableCollection collectionPersister = (QueryableCollection) factory
.getCollectionPersister( role );
if ( !collectionPersister.getElementType().isEntityType() ) {
throw new MappingException(
"collection was not an association: " +
collectionPersister.getRole()
);
}
return collectionPersister.getElementPersister().getEntityName();
}
catch (ClassCastException cce) {
throw new MappingException( "collection role is not queryable " + role );
}
}
/**
* Replace the elements of a collection with the elements of another collection.
*
* @param original The 'source' of the replacement elements (where we copy from)
* @param target The target of the replacement elements (where we copy to)
* @param owner The owner of the collection being merged
* @param copyCache The map of elements already replaced.
* @param session The session from which the merge event originated.
* @return The merged collection.
*/
public Object replaceElements(
Object original,
Object target,
Object owner,
Map copyCache,
SessionImplementor session) {
// TODO: does not work for EntityMode.DOM4J yet!
java.util.Collection result = ( java.util.Collection ) target;
result.clear();
// copy elements into newly empty target collection
Type elemType = getElementType( session.getFactory() );
Iterator iter = ( (java.util.Collection) original ).iterator();
while ( iter.hasNext() ) {
result.add( elemType.replace( iter.next(), null, session, owner, copyCache ) );
}
// if the original is a PersistentCollection, and that original
// was not flagged as dirty, then reset the target's dirty flag
// here after the copy operation.
// </p>
// One thing to be careful of here is a "bare" original collection
// in which case we should never ever ever reset the dirty flag
// on the target because we simply do not know...
if ( original instanceof PersistentCollection ) {
if ( result instanceof PersistentCollection ) {
if ( ! ( ( PersistentCollection ) original ).isDirty() ) {
( ( PersistentCollection ) result ).clearDirty();
}
}
}
return result;
}
/**
* Instantiate a new "underlying" collection exhibiting the same capacity
* charactersitcs and the passed "original".
*
* @param original The original collection.
* @return The newly instantiated collection.
*/
protected Object instantiateResult(Object original) {
// by default just use an unanticipated capacity since we don't
// know how to extract the capacity to use from original here...
return instantiate( -1 );
}
/**
* Instantiate an empty instance of the "underlying" collection (not a wrapper),
* but with the given anticipated size (i.e. accounting for initial capacity
* and perhaps load factor).
*
* @param anticipatedSize The anticipated size of the instaniated collection
* after we are done populating it.
* @return A newly instantiated collection to be wrapped.
*/
public abstract Object instantiate(int anticipatedSize);
/**
* {@inheritDoc}
*/
public Object replace(
final Object original,
final Object target,
final SessionImplementor session,
final Object owner,
final Map copyCache) throws HibernateException {
if ( original == null ) {
return null;
}
if ( !Hibernate.isInitialized( original ) ) {
return target;
}
// for a null target, or a target which is the same as the original, we
// need to put the merged elements in a new collection
Object result = target == null || target == original ? instantiateResult( original ) : target;
//for arrays, replaceElements() may return a different reference, since
//the array length might not match
result = replaceElements( original, result, owner, copyCache, session );
if ( original == target ) {
// get the elements back into the target making sure to handle dirty flag
boolean wasClean = PersistentCollection.class.isInstance( target ) && !( ( PersistentCollection ) target ).isDirty();
//TODO: this is a little inefficient, don't need to do a whole
// deep replaceElements() call
replaceElements( result, target, owner, copyCache, session );
if ( wasClean ) {
( ( PersistentCollection ) target ).clearDirty();
}
result = target;
}
return result;
}
/**
* Get the Hibernate type of the collection elements
*/
public final Type getElementType(SessionFactoryImplementor factory) throws MappingException {
return factory.getCollectionPersister( getRole() ).getElementType();
}
public String toString() {
return getClass().getName() + '(' + getRole() + ')';
}
public String getOnCondition(String alias, SessionFactoryImplementor factory, Map enabledFilters)
throws MappingException {
return getAssociatedJoinable( factory ).filterFragment( alias, enabledFilters );
}
/**
* instantiate a collection wrapper (called when loading an object)
*
* @param key The collection owner key
* @param session The session from which the request is originating.
* @param owner The collection owner
* @return The collection
*/
public Object getCollection(Serializable key, SessionImplementor session, Object owner) {
CollectionPersister persister = getPersister( session );
final PersistenceContext persistenceContext = session.getPersistenceContext();
final EntityMode entityMode = session.getEntityMode();
if (entityMode==EntityMode.DOM4J && !isEmbeddedInXML) {
return UNFETCHED_COLLECTION;
}
// check if collection is currently being loaded
PersistentCollection collection = persistenceContext.getLoadContexts().locateLoadingCollection( persister, key );
if ( collection == null ) {
// check if it is already completely loaded, but unowned
collection = persistenceContext.useUnownedCollection( new CollectionKey(persister, key, entityMode) );
if ( collection == null ) {
// create a new collection wrapper, to be initialized later
collection = instantiate( session, persister, key );
collection.setOwner( owner );
persistenceContext.addUninitializedCollection( persister, collection, key );
// some collections are not lazy:
if ( initializeImmediately( entityMode ) ) {
session.initializeCollection( collection, false );
}
else if ( !persister.isLazy() ) {
persistenceContext.addNonLazyCollection( collection );
}
if ( hasHolder( entityMode ) ) {
session.getPersistenceContext().addCollectionHolder( collection );
}
}
}
collection.setOwner( owner );
return collection.getValue();
}
public boolean hasHolder(EntityMode entityMode) {
return entityMode == EntityMode.DOM4J;
}
protected boolean initializeImmediately(EntityMode entityMode) {
return entityMode == EntityMode.DOM4J;
}
public String getLHSPropertyName() {
return foreignKeyPropertyName;
}
public boolean isXMLElement() {
return true;
}
public Object fromXMLNode(Node xml, Mapping factory) throws HibernateException {
return xml;
}
public void setToXMLNode(Node node, Object value, SessionFactoryImplementor factory)
throws HibernateException {
if ( !isEmbeddedInXML ) {
node.detach();
}
else {
replaceNode( node, (Element) value );
}
}
/**
* We always need to dirty check the collection because we sometimes
* need to incremement version number of owner and also because of
* how assemble/disassemble is implemented for uks
*/
public boolean isAlwaysDirtyChecked() {
return true;
}
public boolean[] toColumnNullness(Object value, Mapping mapping) {
return ArrayHelper.EMPTY_BOOLEAN_ARRAY;
}
}
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