//$Id: IdentityGenerator.java 9681 2006-03-24 18:10:04Z steve.ebersole@jboss.com $
package org.hibernate.id;
import java.io.Serializable;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.PreparedStatement;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.id.insert.InsertGeneratedIdentifierDelegate;
import org.hibernate.id.insert.IdentifierGeneratingInsert;
import org.hibernate.id.insert.AbstractSelectingDelegate;
import org.hibernate.id.insert.AbstractReturningDelegate;
import org.hibernate.id.insert.InsertSelectIdentityInsert;
import org.hibernate.dialect.Dialect;
import org.hibernate.HibernateException;
import org.hibernate.AssertionFailure;
/**
* A generator for use with ANSI-SQL IDENTITY columns used as the primary key.
* The IdentityGenerator for autoincrement/identity key generation.
* <br><br>
* Indicates to the <tt>Session</tt> that identity (ie. identity/autoincrement
* column) key generation should be used.
*
* @author Christoph Sturm
*/
public class IdentityGenerator extends AbstractPostInsertGenerator {
public InsertGeneratedIdentifierDelegate getInsertGeneratedIdentifierDelegate(
PostInsertIdentityPersister persister,
Dialect dialect,
boolean isGetGeneratedKeysEnabled) throws HibernateException {
if ( isGetGeneratedKeysEnabled ) {
return new GetGeneratedKeysDelegate( persister, dialect );
}
else if ( dialect.supportsInsertSelectIdentity() ) {
return new InsertSelectDelegate( persister, dialect );
}
else {
return new BasicDelegate( persister, dialect );
}
}
/**
* Delegate for dealing with IDENTITY columns using JDBC3 getGeneratedKeys
*/
public static class GetGeneratedKeysDelegate
extends AbstractReturningDelegate
implements InsertGeneratedIdentifierDelegate {
private final PostInsertIdentityPersister persister;
private final Dialect dialect;
public GetGeneratedKeysDelegate(PostInsertIdentityPersister persister, Dialect dialect) {
super( persister );
this.persister = persister;
this.dialect = dialect;
}
public IdentifierGeneratingInsert prepareIdentifierGeneratingInsert() {
IdentifierGeneratingInsert insert = new IdentifierGeneratingInsert( dialect );
insert.addIdentityColumn( persister.getRootTableKeyColumnNames()[0] );
return insert;
}
protected PreparedStatement prepare(String insertSQL, SessionImplementor session) throws SQLException {
return session.getBatcher().prepareStatement( insertSQL, true );
}
public Serializable executeAndExtract(PreparedStatement insert) throws SQLException {
insert.executeUpdate();
ResultSet rs = null;
try {
rs = insert.getGeneratedKeys();
return IdentifierGeneratorFactory.getGeneratedIdentity(
rs,
persister.getIdentifierType()
);
}
finally {
if ( rs != null ) {
rs.close();
}
}
}
}
/**
* Delegate for dealing with IDENTITY columns where the dialect supports returning
* the generated IDENTITY value directly from the insert statement.
*/
public static class InsertSelectDelegate
extends AbstractReturningDelegate
implements InsertGeneratedIdentifierDelegate {
private final PostInsertIdentityPersister persister;
private final Dialect dialect;
public InsertSelectDelegate(PostInsertIdentityPersister persister, Dialect dialect) {
super( persister );
this.persister = persister;
this.dialect = dialect;
}
public IdentifierGeneratingInsert prepareIdentifierGeneratingInsert() {
InsertSelectIdentityInsert insert = new InsertSelectIdentityInsert( dialect );
insert.addIdentityColumn( persister.getRootTableKeyColumnNames()[0] );
return insert;
}
protected PreparedStatement prepare(String insertSQL, SessionImplementor session) throws SQLException {
return session.getBatcher().prepareStatement( insertSQL, false );
}
public Serializable executeAndExtract(PreparedStatement insert) throws SQLException {
if ( !insert.execute() ) {
while ( !insert.getMoreResults() && insert.getUpdateCount() != -1 ) {
// do nothing until we hit the rsult set containing the generated id
}
}
ResultSet rs = insert.getResultSet();
try {
return IdentifierGeneratorFactory.getGeneratedIdentity( rs, persister.getIdentifierType() );
}
finally {
rs.close();
}
}
public Serializable determineGeneratedIdentifier(SessionImplementor session, Object entity) {
throw new AssertionFailure( "insert statement returns generated value" );
}
}
/**
* Delegate for dealing with IDENTITY columns where the dialect requires an
* additional command execution to retrieve the generated IDENTITY value
*/
public static class BasicDelegate
extends AbstractSelectingDelegate
implements InsertGeneratedIdentifierDelegate {
private final PostInsertIdentityPersister persister;
private final Dialect dialect;
public BasicDelegate(PostInsertIdentityPersister persister, Dialect dialect) {
super( persister );
this.persister = persister;
this.dialect = dialect;
}
public IdentifierGeneratingInsert prepareIdentifierGeneratingInsert() {
IdentifierGeneratingInsert insert = new IdentifierGeneratingInsert( dialect );
insert.addIdentityColumn( persister.getRootTableKeyColumnNames()[0] );
return insert;
}
protected String getSelectSQL() {
return persister.getIdentitySelectString();
}
protected Serializable getResult(
SessionImplementor session,
ResultSet rs,
Object object) throws SQLException {
return IdentifierGeneratorFactory.getGeneratedIdentity( rs, persister.getIdentifierType() );
}
}
}