OneToOne.java :  » Database-ORM » hibernate » org » hibernate » mapping » Java Open Source

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Middleware LLC.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 *
 */
package org.hibernate.mapping;

import java.util.ArrayList;
import java.util.Iterator;

import org.hibernate.MappingException;
import org.hibernate.type.EntityType;
import org.hibernate.type.ForeignKeyDirection;
import org.hibernate.type.SpecialOneToOneType;
import org.hibernate.type.Type;
import org.hibernate.type.TypeFactory;

/**
 * A one-to-one association mapping
 * @author Gavin King
 */
public class OneToOne extends ToOne {

  private boolean constrained;
  private ForeignKeyDirection foreignKeyType;
  private KeyValue identifier;
  private String propertyName;
  private String entityName;

  public OneToOne(Table table, PersistentClass owner) throws MappingException {
    super(table);
    this.identifier = owner.getKey();
    this.entityName = owner.getEntityName();
  }

  public String getPropertyName() {
    return propertyName;
  }

  public void setPropertyName(String propertyName) {
    this.propertyName = propertyName==null ? null : propertyName.intern();
  }
  
  public String getEntityName() {
    return entityName;
  }

  public void setEntityName(String propertyName) {
    this.entityName = entityName==null ? null : entityName.intern();
  }
  
  public Type getType() throws MappingException {
    if ( getColumnIterator().hasNext() ) {
      return new SpecialOneToOneType(
          getReferencedEntityName(), 
          foreignKeyType, 
          referencedPropertyName,
          isLazy(),
          isUnwrapProxy(),
          entityName,
          propertyName
        );
    }
    else {
      return TypeFactory.oneToOne( 
          getReferencedEntityName(), 
          foreignKeyType, 
          referencedPropertyName,
          isLazy(),
          isUnwrapProxy(),
          isEmbedded(),
          entityName,
          propertyName
        );
    }
  }

  public void createForeignKey() throws MappingException {
    if ( constrained && referencedPropertyName==null) {
      //TODO: handle the case of a foreign key to something other than the pk
      createForeignKeyOfEntity( ( (EntityType) getType() ).getAssociatedEntityName() );
    }
  }

  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 KeyValue 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(KeyValue identifier) {
    this.identifier = identifier;
  }

  public boolean isNullable() {
    return !constrained;
  }

  public Object accept(ValueVisitor visitor) {
    return visitor.accept(this);
  }
  
}