//$Id: OneToOne.java,v 1.5.2.9 2003/11/06 13:43:22 oneovthafew Exp $package net.sf.hibernate.mapping;import java.util.ArrayList;import java.util.Iterator;import net.sf.hibernate.HibernateException;import net.sf.hibernate.MappingException;import net.sf.hibernate.util.ReflectHelper;import net.sf.hibernate.type.EntityType;import net.sf.hibernate.type.ForeignKeyDirection;import net.sf.hibernate.type.TypeFactory;/** * A one-to-one association mapping * @author Gavin King */public class OneToOne extends ToOne {		private boolean constrained;	private ForeignKeyDirection foreignKeyType;	private SimpleValue identifier;		public OneToOne(Table table, SimpleValue identifier) throws MappingException {		super(table);		this.identifier = identifier;	}		public void setTypeByReflection(Class propertyClass, String propertyName) throws MappingException {		try {			if (getType()==null) setType( TypeFactory.oneToOne(				ReflectHelper.reflectedPropertyClass(propertyClass, propertyName), 				foreignKeyType, 				referencedPropertyName			) );		}		catch (HibernateException he) {			throw new MappingException( "Problem trying to set association type by reflection", he );		}	}	public void createForeignKey() {		if ( constrained && referencedPropertyName==null) {			//TODO: handle the case of a foreign key to something other than the pk			createForeignKeyOfClass( ( (EntityType) getType() ).getAssociatedClass() );		}	}		public java.util.List getConstraintColumns() {		ArrayList list = new ArrayList();		Iterator iter = identifier.getColumnIterator();		while ( iter.hasNext() ) list.add( iter.next() );		return list;	}	/**	 * Returns the constrained.	 * @return boolean	 */	public boolean isConstrained() {		return constrained;	}	/**	 * Returns the foreignKeyType.	 * @return AssociationType.ForeignKeyType	 */	public ForeignKeyDirection getForeignKeyType() {		return foreignKeyType;	}	/**	 * Returns the identifier.	 * @return Value	 */	public Value getIdentifier() {		return identifier;	}	/**	 * Sets the constrained.	 * @param constrained The constrained to set	 */	public void setConstrained(boolean constrained) {		this.constrained = constrained;	}	/**	 * Sets the foreignKeyType.	 * @param foreignKeyType The foreignKeyType to set	 */	public void setForeignKeyType(		ForeignKeyDirection foreignKeyType) {		this.foreignKeyType = foreignKeyType;	}	/**	 * Sets the identifier.	 * @param identifier The identifier to set	 */	public void setIdentifier(SimpleValue identifier) {		this.identifier = identifier;	}	public boolean isNullable() {		return !constrained;	}}