//$Id: OQLQuery.java,v 1.4.2.2 2003/09/29 12:06:30 oneovthafew Exp $package net.sf.hibernate.odmg;import org.odmg.ODMGRuntimeException;import org.odmg.QueryException;import org.odmg.QueryInvalidException;import org.odmg.QueryParameterCountInvalidException;import org.odmg.QueryParameterTypeInvalidException;import net.sf.hibernate.HibernateException;import net.sf.hibernate.Query;/** Experimental implementation of the ODMG <tt>OQLQuery</tt> interface. The supported query language is actually the Hibernate query language and the <tt>execute()</tt> method  returns results in the same format as  <tt>Session.find()</tt>.<br> <br> Warning: this implementation will change significantly as  ODMG support matures! */public class OQLQuery implements org.odmg.OQLQuery {		private Transaction tx;	private Query query;	private int param=0;		/**	 * Instantiate an <tt>OQLQuery</tt> for the current transaction.	 */	public OQLQuery(Database db) {		this.tx = db.currentTransaction();	}	/**	 * Instantiate an <tt>OQLQuery</tt> for the given transaction.	 */	public OQLQuery(Transaction tx) {		this.tx = tx;	}	/**	 * Instantiate an <tt>OQLQuery</tt> for the current transaction.	 */	public OQLQuery() {		this.tx = (Transaction) Implementation.getInstance().currentTransaction();	}	/**	 * Get the underlying Hibernate <tt>Query</tt>.	 */	public Query getQuery() {		return query;	}	/**	 * Set the Hibernate query string. Scalar return values are not supported.	 * @see org.odmg.OQLQuery#create(String)	 */	public void create(String queryString) throws QueryInvalidException {		//TODO: the right exception		try {			this.query = tx.getSession().createQuery(queryString);		}		catch (HibernateException he) {			throw new ODMGRuntimeException( he.getMessage() );		}	}	/**	 * Bind a value to the next enumerated parameter. JavaDoc requires a second sentence.	 *	 * @see org.odmg.OQLQuery#bind(Object)	 */	public void bind(Object parameter) throws	QueryParameterCountInvalidException, QueryParameterTypeInvalidException {		//TODO: the right exception		try {			query.setParameter(param++, parameter);		}		catch (HibernateException he) {			throw new ODMGRuntimeException( he.getMessage() );		}	}	/**	 * Get the query results as a collection. JavaDoc requires a second sentence.	 * @see org.odmg.OQLQuery#execute()	 */	public Object execute() throws QueryException {				//TODO: how are results meant to be returned in ODMG?				try {			return query.list();		}		catch (HibernateException he) {			throw new QueryException( he.getMessage() );		}	}}