我找到了解决方案:
public class DefaultPostgresKeyServer
{
private Session session;
private Iterator<BigInteger> iter;
private long batchSize;
public DefaultPostgresKeyServer (Session sess, long batchFetchSize)
{
this.session=sess;
batchSize = batchFetchSize;
iter = Collections.<BigInteger>emptyList().iterator();
}
@SuppressWarnings("unchecked")
public Long getNextKey()
{
if ( ! iter.hasNext() )
{
Query query = session.createsqlQuery( "SELECT nextval( 'mySchema.mySequence' ) FROM generate_series( 1, " + batchSize + " )" );
iter = (Iterator<BigInteger>) query.list().iterator();
}
return iter.next().longValue() ;
}
}