IdentifierCollection.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 org.hibernate.MappingException;
import org.hibernate.engine.Mapping;

/**
 * A collection with a synthetic "identifier" column
 */
public abstract class IdentifierCollection extends Collection {

  public static final String DEFAULT_IDENTIFIER_COLUMN_NAME = "id";

  private KeyValue identifier;

  public IdentifierCollection(PersistentClass owner) {
    super(owner);
  }

  public KeyValue getIdentifier() {
    return identifier;
  }
  public void setIdentifier(KeyValue identifier) {
    this.identifier = identifier;
  }
  public final boolean isIdentified() {
    return true;
  }

  void createPrimaryKey() {
    if ( !isOneToMany() ) {
      PrimaryKey pk = new PrimaryKey();
      pk.addColumns( getIdentifier().getColumnIterator() );
      getCollectionTable().setPrimaryKey(pk);
    }
    else {
      // don't create a unique key, 'cos some
      // databases don't like a UK on nullable
      // columns
      //getCollectionTable().createUniqueKey( getIdentifier().getConstraintColumns() );
    }
    // create an index on the key columns??
  }

  public void validate(Mapping mapping) throws MappingException {
    super.validate(mapping);
    if ( !getIdentifier().isValid(mapping) ) {
      throw new MappingException(
        "collection id mapping has wrong number of columns: " +
        getRole() +
        " type: " +
        getIdentifier().getType().getName()
      );
    }
  }

}