//$Id: SelectGenerator.java 11061 2007-01-19 12:55:07Z [email protected] $
package org.hibernate.id;
import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;
import org.hibernate.MappingException;
import org.hibernate.HibernateException;
import org.hibernate.id.insert.InsertGeneratedIdentifierDelegate;
import org.hibernate.id.insert.IdentifierGeneratingInsert;
import org.hibernate.id.insert.AbstractSelectingDelegate;
import org.hibernate.dialect.Dialect;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.engine.ValueInclusion;
import org.hibernate.type.Type;
/**
* A generator that selects the just inserted row to determine the identifier
* value assigned by the database. The correct row is located using a unique
* key.
* <p/>
* One mapping parameter is required: key (unless a natural-id is defined in the mapping).
*
* @author Gavin King
*/
public class SelectGenerator extends AbstractPostInsertGenerator implements Configurable {
private String uniqueKeyPropertyName;
public void configure(Type type, Properties params, Dialect d) throws MappingException {
uniqueKeyPropertyName = params.getProperty( "key" );
}
public InsertGeneratedIdentifierDelegate getInsertGeneratedIdentifierDelegate(
PostInsertIdentityPersister persister,
Dialect dialect,
boolean isGetGeneratedKeysEnabled) throws HibernateException {
return new SelectGeneratorDelegate( persister, dialect, uniqueKeyPropertyName );
}
private static String determineNameOfPropertyToUse(PostInsertIdentityPersister persister, String supplied) {
if ( supplied != null ) {
return supplied;
}
int[] naturalIdPropertyIndices = persister.getNaturalIdentifierProperties();
if ( naturalIdPropertyIndices == null ){
throw new IdentifierGenerationException(
"no natural-id property defined; need to specify [key] in " +
"generator parameters"
);
}
if ( naturalIdPropertyIndices.length > 1 ) {
throw new IdentifierGenerationException(
"select generator does not currently support composite " +
"natural-id properties; need to specify [key] in generator parameters"
);
}
ValueInclusion inclusion = persister.getPropertyInsertGenerationInclusions() [ naturalIdPropertyIndices[0] ];
if ( inclusion != ValueInclusion.NONE ) {
throw new IdentifierGenerationException(
"natural-id also defined as insert-generated; need to specify [key] " +
"in generator parameters"
);
}
return persister.getPropertyNames() [ naturalIdPropertyIndices[0] ];
}
/**
* The delegate for the select generation strategy.
*/
public static class SelectGeneratorDelegate
extends AbstractSelectingDelegate
implements InsertGeneratedIdentifierDelegate {
private final PostInsertIdentityPersister persister;
private final Dialect dialect;
private final String uniqueKeyPropertyName;
private final Type uniqueKeyType;
private final Type idType;
private final String idSelectString;
private SelectGeneratorDelegate(
PostInsertIdentityPersister persister,
Dialect dialect,
String suppliedUniqueKeyPropertyName) {
super( persister );
this.persister = persister;
this.dialect = dialect;
this.uniqueKeyPropertyName = determineNameOfPropertyToUse( persister, suppliedUniqueKeyPropertyName );
idSelectString = persister.getSelectByUniqueKeyString( uniqueKeyPropertyName );
uniqueKeyType = persister.getPropertyType( uniqueKeyPropertyName );
idType = persister.getIdentifierType();
}
public IdentifierGeneratingInsert prepareIdentifierGeneratingInsert() {
return new IdentifierGeneratingInsert( dialect );
}
// AbstractSelectingDelegate impl ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
protected String getSelectSQL() {
return idSelectString;
}
protected void bindParameters(
SessionImplementor session,
PreparedStatement ps,
Object entity) throws SQLException {
Object uniqueKeyValue = persister.getPropertyValue( entity, uniqueKeyPropertyName, session.getEntityMode() );
uniqueKeyType.nullSafeSet( ps, uniqueKeyValue, 1, session );
}
protected Serializable getResult(
SessionImplementor session,
ResultSet rs,
Object entity) throws SQLException {
if ( !rs.next() ) {
throw new IdentifierGenerationException(
"the inserted row could not be located by the unique key: " +
uniqueKeyPropertyName
);
}
return ( Serializable ) idType.nullSafeGet(
rs,
persister.getRootTableKeyColumnNames(),
session,
entity
);
}
}
}
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