Bug 138828 Export data column are disordered
Steps to reproduce: 1.Add a sample data source and a data set with table "CUSTOMERS" 2.Preview in Web Viewer 3.Click "Export data", choose columns "CUSTOMERNAME","PHONE","CITY","STATE" to be exported, click "OK" Expected result: The exported columns is alphabetic order or the same order as selected columns Actual result: The exported columns is disordered. they are "STATE","CITY","CUSTOMERNAME","PHONE".
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/service/api/IViewerReportService.java
* @param objectId
	 * @param renderOptions
	 * @param activeIds
	 * @return
	 * @throws ReportServiceException
	 */
	ByteArrayOutputStream getPageByObjectId( String docName, String objectId,
			InputOptions renderOptions, List activeIds )
			throws ReportServiceException;
	/**
	 * Render a reportlet. This is similar to getPageByObjectId. The difference
	 * is that while getPageByObjectId returns the first page containing the
	 * object, this method return all pages containing the object.
	 * 
	 * @param docName
	 * @param objectId
	 * @param renderOptions
	 * @param activeIds
	 * @return
	 * @throws ReportServiceException
	 */
	ByteArrayOutputStream renderReportlet( String docName, String objectId,
			InputOptions renderOptions, List activeIds )
			throws ReportServiceException;
	/**
	 * Render the whole report to the OutputStream
	 * 
	 * @param docName
	 * @param pageRange
	 * @param renderOptions