如何使用 POI 为 HSSCell 设置自定义颜色？

Question

I would like to set a custom color to a CellStyle in POI, but it doesn't seem to be getting applied.

I have the following code:

HSSFWorkbook workBook = new HSSFWorkbook();
HSSFSheet sheet = workBook.createSheet("Bank Statement");

HSSFPalette palette = workBook.getCustomPalette();
palette.setColorAtIndex((short) 1, (byte) 60, (byte) 120, (byte) 216);

HSSFColor color = palette.findSimilarColor(60, 120, 216);

CellStyle cellStyleHeader = workBook.createCellStyle();
cellStyleHeader.setFillPattern(FillPatternType.SOLID_FOREGROUND);
cellStyleHeader.setFillForegroundColor(color);
cellStyleHeader.setFont(createHeaderFont(workBook));

HSSFCell cell = row.createCell(cellIndex);
cell.setCellType(CellType.STRING);
cell.setCellValue("Date");
cell.setCellStyle(style);

No background color is being applied. The color is white. The value of color is non null, but is not the same color (when run via a debugger):

What's the correct way to set a custom color?

Answer 1

Seems void setFillForegroundColor(Color color) does not work properly for HSSFColor .

In the binary Excel file format ( *.xls , HSSF ) all colors need to be indexed in a color palette. So a custom color needs overwriting a default palette color. And to set the fill foreground color, the index should be used rather than the color itself. So void setFillForegroundColor(short bg) should be used for HSSF .

Following code works to set custom fill foreground color for XSSF as well as for HSSF . For HSSF it overwrites the HSSFColor.HSSFColorPredefined.LIME color in palette.

import java.io.FileOutputStream;

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.xssf.usermodel.*;
import org.apache.poi.hssf.util.HSSFColor;

public class CreateExcelCellFillCustomColor {

 public static void main(String[] args) throws Exception {

  byte[] rgb = new byte[]{(byte) 60, (byte) 120, (byte) 216};

  Workbook workbook = new HSSFWorkbook(); String filePath = "./Excel.xls";
  //Workbook workbook = new XSSFWorkbook(); String filePath = "./Excel.xlsx";

  CellStyle cellStyle = workbook.createCellStyle();
  cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
  if (workbook instanceof XSSFWorkbook) {
   XSSFColor color = new XSSFColor(rgb, null);
   cellStyle.setFillForegroundColor(color);
  } else if (workbook instanceof HSSFWorkbook) {
   HSSFWorkbook hssfworkbook = (HSSFWorkbook)workbook;
   HSSFPalette palette = hssfworkbook.getCustomPalette();
   palette.setColorAtIndex(HSSFColor.HSSFColorPredefined.LIME.getIndex(), rgb[0], rgb[1], rgb[2]);
   HSSFColor color = palette.findSimilarColor(rgb[0], rgb[1], rgb[2]);
   //cellStyle.setFillForegroundColor(color); // does not work correctly for HSSF
   cellStyle.setFillForegroundColor(color.getIndex());   
  }
  
  Sheet sheet = workbook.createSheet();
  Cell cell = sheet.createRow(0).createCell(0);
  cell.setCellStyle(cellStyle);
  cell.setCellValue("test");

  FileOutputStream out = new FileOutputStream(filePath);
  workbook.write(out);
  out.close();
  workbook.close();

 }

}