// $Id: DbTimestampType.java 7830 2005-08-11 00:10:26Z oneovthafew $
package org.hibernate.type;
import java.sql.Timestamp;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.ResultSet;
import java.sql.CallableStatement;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.dialect.Dialect;
import org.hibernate.exception.JDBCExceptionHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* <tt>dbtimestamp</tt>: An extension of {@link TimestampType} which
* maps to the database's current timestamp, rather than the jvm's
* current timestamp.
* <p/>
* Note: May/may-not cause issues on dialects which do not properly support
* a true notion of timestamp (Oracle < 8, for example, where only its DATE
* datatype is supported). Depends on the frequency of DML operations...
*
* @author Steve Ebersole
*/
public class DbTimestampType extends TimestampType implements VersionType {
private static final Logger log = LoggerFactory.getLogger( DbTimestampType.class );
public String getName() { return "dbtimestamp"; }
public Object seed(SessionImplementor session) {
if ( session == null ) {
log.trace( "incoming session was null; using current jvm time" );
return super.seed( session );
}
else if ( !session.getFactory().getDialect().supportsCurrentTimestampSelection() ) {
log.debug( "falling back to vm-based timestamp, as dialect does not support current timestamp selection" );
return super.seed( session );
}
else {
return getCurrentTimestamp( session );
}
}
private Timestamp getCurrentTimestamp(SessionImplementor session) {
Dialect dialect = session.getFactory().getDialect();
String timestampSelectString = dialect.getCurrentTimestampSelectString();
if ( dialect.isCurrentTimestampSelectStringCallable() ) {
return useCallableStatement( timestampSelectString, session );
}
else {
return usePreparedStatement( timestampSelectString, session );
}
}
private Timestamp usePreparedStatement(String timestampSelectString, SessionImplementor session) {
PreparedStatement ps = null;
try {
ps = session.getBatcher().prepareStatement( timestampSelectString );
ResultSet rs = session.getBatcher().getResultSet( ps );
rs.next();
Timestamp ts = rs.getTimestamp( 1 );
if ( log.isTraceEnabled() ) {
log.trace(
"current timestamp retreived from db : " + ts +
" (nanos=" + ts.getNanos() +
", time=" + ts.getTime() + ")"
);
}
return ts;
}
catch( SQLException sqle ) {
throw JDBCExceptionHelper.convert(
session.getFactory().getSQLExceptionConverter(),
sqle,
"could not select current db timestamp",
timestampSelectString
);
}
finally {
if ( ps != null ) {
try {
session.getBatcher().closeStatement( ps );
}
catch( SQLException sqle ) {
log.warn( "unable to clean up prepared statement", sqle );
}
}
}
}
private Timestamp useCallableStatement(String callString, SessionImplementor session) {
CallableStatement cs = null;
try {
cs = session.getBatcher().prepareCallableStatement( callString );
cs.registerOutParameter( 1, java.sql.Types.TIMESTAMP );
cs.execute();
Timestamp ts = cs.getTimestamp( 1 );
if ( log.isTraceEnabled() ) {
log.trace(
"current timestamp retreived from db : " + ts +
" (nanos=" + ts.getNanos() +
", time=" + ts.getTime() + ")"
);
}
return ts;
}
catch( SQLException sqle ) {
throw JDBCExceptionHelper.convert(
session.getFactory().getSQLExceptionConverter(),
sqle,
"could not call current db timestamp function",
callString
);
}
finally {
if ( cs != null ) {
try {
session.getBatcher().closeStatement( cs );
}
catch( SQLException sqle ) {
log.warn( "unable to clean up callable statement", sqle );
}
}
}
}
}