Bug 361443 Excel ODA
data/org.eclipse.birt.report.data.oda.excel/src/org/eclipse/birt/report/data/oda/excel/impl/ExcelFileQuery.java
public void setAppContext(Object context) throws OdaException {
		this.appContext = (Map) context;
	}
	/*
	 * @see org.eclipse.datatools.connectivity.oda.IQuery#close()
	 */
	public void close() throws OdaException {
		maxRows = 0;
		resultSetMetaData = null;
	}
	/*
	 * @see org.eclipse.datatools.connectivity.oda.IQuery#getMetaData()
	 */
	public IResultSetMetaData getMetaData() throws OdaException {
		if (resultSetMetaData == null)
			prepareMetaData();
		return resultSetMetaData;
	}
	/*
	 * @see org.eclipse.datatools.connectivity.oda.IQuery#executeQuery()
	 */
	public IResultSet executeQuery() throws OdaException {
		if (this.isInvalidQuery)
			throw new OdaException(
					Messages.getString("query_COMMAND_NOT_VALID")); 
		return new ResultSet(new ExcelFileSource(this.connProperties,
				this.currentTableName, worksheetNames,
				this.maxRows, this.resultSetMetaData,
				this.resultSetMetaDataHelper, appContext), this.resultSetMetaData);
	}