//$Id: PersistentSet.java 10588 2006-10-16 15:47:19Z [email protected] $
package org.hibernate.collection;
import java.io.Serializable;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import org.hibernate.EntityMode;
import org.hibernate.HibernateException;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.loader.CollectionAliases;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.type.Type;
/**
* A persistent wrapper for a <tt>java.util.Set</tt>. The underlying
* collection is a <tt>HashSet</tt>.
*
* @see java.util.HashSet
* @author Gavin King
*/
public class PersistentSet extends AbstractPersistentCollection implements java.util.Set {
protected Set set;
protected transient List tempList;
/**
* Empty constructor.
* <p/>
* Note: this form is not ever ever ever used by Hibernate; it is, however,
* needed for SOAP libraries and other such marshalling code.
*/
public PersistentSet() {
// intentionally empty
}
/**
* Constructor matching super. Instantiates a lazy set (the underlying
* set is un-initialized).
*
* @param session The session to which this set will belong.
*/
public PersistentSet(SessionImplementor session) {
super( session );
}
/**
* Instantiates a non-lazy set (the underlying set is constructed
* from the incoming set reference).
*
* @param session The session to which this set will belong.
* @param set The underlying set data.
*/
public PersistentSet(SessionImplementor session, java.util.Set set) {
super(session);
// Sets can be just a view of a part of another collection.
// do we need to copy it to be sure it won't be changing
// underneath us?
// ie. this.set.addAll(set);
this.set = set;
setInitialized();
setDirectlyAccessible(true);
}
public Serializable getSnapshot(CollectionPersister persister)
throws HibernateException {
EntityMode entityMode = getSession().getEntityMode();
//if (set==null) return new Set(session);
HashMap clonedSet = new HashMap( set.size() );
Iterator iter = set.iterator();
while ( iter.hasNext() ) {
Object copied = persister.getElementType()
.deepCopy( iter.next(), entityMode, persister.getFactory() );
clonedSet.put(copied, copied);
}
return clonedSet;
}
public Collection getOrphans(Serializable snapshot, String entityName) throws HibernateException {
java.util.Map sn = (java.util.Map) snapshot;
return getOrphans( sn.keySet(), set, entityName, getSession() );
}
public boolean equalsSnapshot(CollectionPersister persister) throws HibernateException {
Type elementType = persister.getElementType();
java.util.Map sn = (java.util.Map) getSnapshot();
if ( sn.size()!=set.size() ) {
return false;
}
else {
Iterator iter = set.iterator();
while ( iter.hasNext() ) {
Object test = iter.next();
Object oldValue = sn.get(test);
if ( oldValue==null || elementType.isDirty( oldValue, test, getSession() ) ) return false;
}
return true;
}
}
public boolean isSnapshotEmpty(Serializable snapshot) {
return ( (java.util.Map) snapshot ).isEmpty();
}
public void beforeInitialize(CollectionPersister persister, int anticipatedSize) {
this.set = ( Set ) persister.getCollectionType().instantiate( anticipatedSize );
}
public void initializeFromCache(CollectionPersister persister, Serializable disassembled, Object owner)
throws HibernateException {
Serializable[] array = ( Serializable[] ) disassembled;
int size = array.length;
beforeInitialize( persister, size );
for (int i = 0; i < size; i++ ) {
Object element = persister.getElementType().assemble( array[i], getSession(), owner );
if ( element != null ) {
set.add( element );
}
}
}
public boolean empty() {
return set.isEmpty();
}
/**
* @see java.util.Set#size()
*/
public int size() {
return readSize() ? getCachedSize() : set.size();
}
/**
* @see java.util.Set#isEmpty()
*/
public boolean isEmpty() {
return readSize() ? getCachedSize()==0 : set.isEmpty();
}
/**
* @see java.util.Set#contains(Object)
*/
public boolean contains(Object object) {
Boolean exists = readElementExistence(object);
return exists==null ?
set.contains(object) :
exists.booleanValue();
}
/**
* @see java.util.Set#iterator()
*/
public Iterator iterator() {
read();
return new IteratorProxy( set.iterator() );
}
/**
* @see java.util.Set#toArray()
*/
public Object[] toArray() {
read();
return set.toArray();
}
/**
* @see java.util.Set#toArray(Object[])
*/
public Object[] toArray(Object[] array) {
read();
return set.toArray(array);
}
/**
* @see java.util.Set#add(Object)
*/
public boolean add(Object value) {
Boolean exists = isOperationQueueEnabled() ? readElementExistence( value ) : null;
if ( exists == null ) {
initialize( true );
if ( set.add( value ) ) {
dirty();
return true;
}
else {
return false;
}
}
else if ( exists.booleanValue() ) {
return false;
}
else {
queueOperation( new SimpleAdd(value) );
return true;
}
}
/**
* @see java.util.Set#remove(Object)
*/
public boolean remove(Object value) {
Boolean exists = isPutQueueEnabled() ? readElementExistence( value ) : null;
if ( exists==null ) {
initialize( true );
if ( set.remove( value ) ) {
dirty();
return true;
}
else {
return false;
}
}
else if ( exists.booleanValue() ) {
queueOperation( new SimpleRemove(value) );
return true;
}
else {
return false;
}
}
/**
* @see java.util.Set#containsAll(Collection)
*/
public boolean containsAll(Collection coll) {
read();
return set.containsAll(coll);
}
/**
* @see java.util.Set#addAll(Collection)
*/
public boolean addAll(Collection coll) {
if ( coll.size() > 0 ) {
initialize( true );
if ( set.addAll( coll ) ) {
dirty();
return true;
}
else {
return false;
}
}
else {
return false;
}
}
/**
* @see java.util.Set#retainAll(Collection)
*/
public boolean retainAll(Collection coll) {
initialize( true );
if ( set.retainAll( coll ) ) {
dirty();
return true;
}
else {
return false;
}
}
/**
* @see java.util.Set#removeAll(Collection)
*/
public boolean removeAll(Collection coll) {
if ( coll.size() > 0 ) {
initialize( true );
if ( set.removeAll( coll ) ) {
dirty();
return true;
}
else {
return false;
}
}
else {
return false;
}
}
/**
* @see java.util.Set#clear()
*/
public void clear() {
if ( isClearQueueEnabled() ) {
queueOperation( new Clear() );
}
else {
initialize( true );
if ( !set.isEmpty() ) {
set.clear();
dirty();
}
}
}
public String toString() {
//if (needLoading) return "asleep";
read();
return set.toString();
}
public Object readFrom(
ResultSet rs,
CollectionPersister persister,
CollectionAliases descriptor,
Object owner) throws HibernateException, SQLException {
Object element = persister.readElement( rs, owner, descriptor.getSuffixedElementAliases(), getSession() );
if (element!=null) tempList.add(element);
return element;
}
public void beginRead() {
super.beginRead();
tempList = new ArrayList();
}
public boolean endRead() {
set.addAll(tempList);
tempList = null;
setInitialized();
return true;
}
public Iterator entries(CollectionPersister persister) {
return set.iterator();
}
public Serializable disassemble(CollectionPersister persister)
throws HibernateException {
Serializable[] result = new Serializable[ set.size() ];
Iterator iter = set.iterator();
int i=0;
while ( iter.hasNext() ) {
result[i++] = persister.getElementType().disassemble( iter.next(), getSession(), null );
}
return result;
}
public Iterator getDeletes(CollectionPersister persister, boolean indexIsFormula) throws HibernateException {
Type elementType = persister.getElementType();
final java.util.Map sn = (java.util.Map) getSnapshot();
ArrayList deletes = new ArrayList( sn.size() );
Iterator iter = sn.keySet().iterator();
while ( iter.hasNext() ) {
Object test = iter.next();
if ( !set.contains(test) ) {
// the element has been removed from the set
deletes.add(test);
}
}
iter = set.iterator();
while ( iter.hasNext() ) {
Object test = iter.next();
Object oldValue = sn.get(test);
if ( oldValue!=null && elementType.isDirty( test, oldValue, getSession() ) ) {
// the element has changed
deletes.add(oldValue);
}
}
return deletes.iterator();
}
public boolean needsInserting(Object entry, int i, Type elemType) throws HibernateException {
final java.util.Map sn = (java.util.Map) getSnapshot();
Object oldValue = sn.get(entry);
// note that it might be better to iterate the snapshot but this is safe,
// assuming the user implements equals() properly, as required by the Set
// contract!
return oldValue==null || elemType.isDirty( oldValue, entry, getSession() );
}
public boolean needsUpdating(Object entry, int i, Type elemType) {
return false;
}
public boolean isRowUpdatePossible() {
return false;
}
public Object getIndex(Object entry, int i, CollectionPersister persister) {
throw new UnsupportedOperationException("Sets don't have indexes");
}
public Object getElement(Object entry) {
return entry;
}
public Object getSnapshotElement(Object entry, int i) {
throw new UnsupportedOperationException("Sets don't support updating by element");
}
public boolean equals(Object other) {
read();
return set.equals(other);
}
public int hashCode() {
read();
return set.hashCode();
}
public boolean entryExists(Object key, int i) {
return true;
}
public boolean isWrapper(Object collection) {
return set==collection;
}
final class Clear implements DelayedOperation {
public void operate() {
set.clear();
}
public Object getAddedInstance() {
return null;
}
public Object getOrphan() {
throw new UnsupportedOperationException("queued clear cannot be used with orphan delete");
}
}
final class SimpleAdd implements DelayedOperation {
private Object value;
public SimpleAdd(Object value) {
this.value = value;
}
public void operate() {
set.add(value);
}
public Object getAddedInstance() {
return value;
}
public Object getOrphan() {
return null;
}
}
final class SimpleRemove implements DelayedOperation {
private Object value;
public SimpleRemove(Object value) {
this.value = value;
}
public void operate() {
set.remove(value);
}
public Object getAddedInstance() {
return null;
}
public Object getOrphan() {
return value;
}
}
}
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