Bug 361443 Excel ODA
data/org.eclipse.birt.report.data.oda.excel/src/org/eclipse/birt/report/data/oda/excel/impl/ExcelFileQuery.java
* Prepare the meta data which will be used in execution of a query text. It
	 * sets the value of two member variables: resultSetMetaData and
	 * currentTableName
	 *
	 * @param queryText
	 * @throws OdaException
	 */
	private void prepareMetaData() throws OdaException {
		
		
		ExcelFileSource excelFileReader = new ExcelFileSource(connProperties,
				currentTableName, worksheetNames, maxRowsToRead, null,
				null, appContext);
		String[] allColumnNames;
		String[] allColumnTypes;
		allColumnNames = this.hasColumnNames ? discoverActualColumnMetaData(
				NAME_LITERAL, currentTableName)
				: createTempColumnNames(excelFileReader.getColumnCount());
		allColumnTypes = this.hasTypeLine ? discoverActualColumnMetaData(
				TYPE_LITERAL, currentTableName)
				: createTempColumnTypes(excelFileReader.getColumnCount());
		resultSetMetaData = new ResultSetMetaData(allColumnNames,
				allColumnTypes);
		if (allColumnNames.length != allColumnTypes.length)
			throw new OdaException(
					Messages.getString("invalid_excelfile_format")); 
		
		String[] queryColumnNames = null;
		String[] queryColumnTypes = null;
		String[] queryColumnLables = null;