src/org/tiefaces/components/websheet/chart/ChartHelper.java
private void initXSSFChartsMap(final XSSFWorkbook wb,
			final ChartsData chartsData) {

		initAnchorsMap(wb, chartsData);
		Map<String, ClientAnchor> anchorMap = chartsData
				.getChartAnchorsMap();

		Map<String, BufferedImage> chartMap = chartsData.getChartsMap();
		Map<String, ChartData> chartDataMap = chartsData.getChartDataMap();
		chartMap.clear();
		chartDataMap.clear();

		for (int i = 0; i < wb.getNumberOfSheets(); i++) {
			XSSFSheet sheet = wb.getSheetAt(i);
			XSSFDrawing drawing = sheet.createDrawingPatriarch();
			List<XSSFChart> charts = drawing.getCharts();
			if ((charts != null) && (!charts.isEmpty())) {
				for (XSSFChart chart : charts) {
					generateSingleXSSFChart(chart,
							getChartIdFromParent(chart,
									sheet.getSheetName()),
							sheet, anchorMap, chartMap, chartDataMap);
				}
			}
		}

	}
private void initXSSFChartsMap(final XSSFWorkbook wb,
			final ChartsData chartsData) {

		initAnchorsMap(wb, chartsData);
		Map<String, ClientAnchor> anchorMap = chartsData
				.getChartAnchorsMap();

		Map<String, BufferedImage> chartMap = chartsData.getChartsMap();
		Map<String, ChartData> chartDataMap = chartsData.getChartDataMap();
		chartMap.clear();
		chartDataMap.clear();

		for (int i = 0; i < wb.getNumberOfSheets(); i++) {
			XSSFSheet sheet = wb.getSheetAt(i);
			XSSFDrawing drawing = sheet.createDrawingPatriarch();
			List<XSSFChart> charts = drawing.getCharts();
			if ((charts != null) && (!charts.isEmpty())) {
				for (XSSFChart chart : charts) {
					generateSingleXSSFChart(chart,
							getChartIdFromParent(chart,
									sheet.getSheetName()),
							sheet, anchorMap, chartMap, chartDataMap);
				}
			}
		}

	}
initial chart map for XSSF format file. XSSF file is actually the only
format in POI support chart object.

@param wb
xssf workbook.
@param chartsData
the charts data