Apache POI柱状图负数值柱体无颜色问题求助

问题根源在于Apache POI的高层XDDF API默认未处理负值柱体的填充配置，需通过底层XML对象显式设置正负值柱体的填充规则，确保负值柱体正常显示颜色。

修改后的完整代码如下：

public class BarChart2 {

    public static void main(String[] args) throws Exception {
        try (XSSFWorkbook wb = new XSSFWorkbook()) {

            String sheetName = "test";
            
            XSSFSheet sheet = wb.createSheet(sheetName);

            // 创建数据行
            Row row = sheet.createRow((short) 0);
            Cell cell = row.createCell((short) 0);
            cell.setCellValue("Jan");
            cell = row.createCell((short) 1);
            cell.setCellValue(23);
            
            row = sheet.createRow((short) 1);           
            cell = row.createCell((short) 0);
            cell.setCellValue("Feb");           
            cell = row.createCell((short) 1);
            cell.setCellValue(-5);
            
            row = sheet.createRow((short) 2);       
            cell = row.createCell((short) 0);
            cell.setCellValue("March");         
            cell = row.createCell((short) 1);
            cell.setCellValue(15);

            XSSFDrawing drawing = sheet.createDrawingPatriarch();
            XSSFClientAnchor anchor = drawing.createAnchor(5, 5, 5, 5, 5, 0, 12, 20);

            XSSFChart chart = drawing.createChart(anchor);
            chart.setTitleText("Report" );
            chart.setTitleOverlay(false);
            
            XDDFCategoryAxis bottomAxis = chart.createCategoryAxis(AxisPosition.BOTTOM);
            bottomAxis.setTitle("Month");
            XDDFValueAxis leftAxis = chart.createValueAxis(AxisPosition.LEFT);
            leftAxis.setTitle("Area");
            leftAxis.setCrosses(AxisCrosses.AUTO_ZERO);

            XDDFDataSource<String> months = XDDFDataSourcesFactory.fromStringCellRange(sheet,
                    new CellRangeAddress(0, 2, 0, 0));

            XDDFNumericalDataSource<Double> values = XDDFDataSourcesFactory.fromNumericCellRange(sheet,
                    new CellRangeAddress(0, 2, 1, 1));
            
            XDDFBarChartData data = (XDDFBarChartData) chart.createData(ChartTypes.BAR, bottomAxis, leftAxis);
            XDDFBarChartData.Series series1 = (XDDFBarChartData.Series) data.addSeries(months, values);
            series1.setTitle("Month", null);
            data.setVaryColors(false);
            chart.plot(data);
            
            data.setBarDirection(BarDirection.COL);

            // 核心配置：设置正负值柱体颜色
            CTBarSer ctBarSer = series1.getXmlObject();
            // 设置正值柱体填充色（示例：深绿色）
            CTSolidFill positiveFill = ctBarSer.getSpPr().addNewSolidFill();
            positiveFill.addNewSrgbClr().setVal(new byte[]{(byte)0x2E, (byte)0x7D, (byte)0x32});
            
            // 开启负值颜色反转，并设置负值柱体填充色（示例：深红色）
            ctBarSer.addNewInvertIfNegative().setVal(true);
            CTColor negativeColor = CTColor.Factory.newInstance();
            negativeColor.addNewSrgbClr().setVal(new byte[]{(byte)0xC6, (byte)0x28, (byte)0x28});
            ctBarSer.addNewNegativeColor().setVal(negativeColor);

            // 写入文件
            String filename = "test.xlsx";
            try (FileOutputStream fileOut = new FileOutputStream("C:\\"+filename)) {
                wb.write(fileOut);
            }
        }
    }
}

关键修改说明： #

1. 直接转换图表数据类型：将chart.createData结果转为XDDFBarChartData，避免后续强制转换的冗余操作。
2. 底层XML对象控制：通过series1.getXmlObject()获取CTBarSer，这是控制柱状图系列样式的核心底层结构。
3. 正负值颜色分离配置：
   • 为正值柱体设置实心填充色
   • 开启InvertIfNegative规则，并单独指定负值柱体的填充颜色

修改后，负值柱体将正常显示为指定颜色，不会再出现空柱情况。

内容的提问来源于stack exchange，提问作者Anil Jagtap