使用Apache POI获取Excel填充颜色

Question

我正在使用Apache POI 3.17来阅读Excel 2013工作簿。 用户直接在Excel中创建和编辑工作簿。 然后我运行一个Java 8程序，它使用POI来读取和处理工作簿。

有些单元格是彩色编码的，所以我需要获得填充颜色。 在许多情况下，这种方法很好，但有一组灰色/银色的颜色不起作用，我不确定为什么。

例如，Excel单元格如下所示：

我获取填充颜色的代码是：

private String getFillColor(XSSFCell cell) {
    String fColorString = "None";
    if (cell != null) {
        XSSFCellStyle cellStyle = cell.getCellStyle();

        short sColorFore = cellStyle.getFillForegroundColor();
        short sColorBack = cellStyle.getFillBackgroundColor();
        XSSFColor xColorFore =  cellStyle.getFillForegroundColorColor();
        XSSFColor xColorBack =  cellStyle.getFillBackgroundColorColor();

        String s = "";
        s += " indexFore=" + sColorFore;
        s += " indexBack=" + sColorBack;
        s += " colorFore=" + ((xColorFore == null) ? "Null" : xColorFore.getARGBHex());
        s += " colorBack=" + ((xColorBack == null) ? "Null" : xColorBack.getARGBHex());
        System.out.println("Cell=" + cell.getAddress() + " " + cell.getStringCellValue() + s);

        if (xColorFore != null) {
            fColorString = xColorFore.getARGBHex();
        }8
    }
    return fColorString;
}

调用上面每个示例Excel单元格时的结果是：

Cell = BBH52 Pink indexFore = 0 indexBack = 64 colorFore = FFF79646 colorBack = null

Cell = BBH53无填充indexFore = 64 indexBack = 64 colorFore = Null colorBack = Null

Cell = BBH54 Gray 1 indexFore = 0 indexBack = 64 colorFore = FFFFFFFF colorBack = null

Cell = BBH55 Gray 2 indexFore = 0 indexBack = 64 colorFore = FFFFFFFF colorBack = null

Cell = BBH56 Gray 3 indexFore = 0 indexBack = 64 colorFore = FFFFFFFF colorBack = null

Cell = BBH57 Gray 4 indexFore = 0 indexBack = 64 colorFore = FFFFFFFF colorBack = null

Cell = BBH58 Gray 5 indexFore = 0 indexBack = 64 colorFore = FFFFFFFF colorBack = null

Cell = BBH59白色indexFore = 0 indexBack = 64 colorFore = FFFFFFFF colorBack = null

知道为什么灰色和白色的阴影都转换为FFFFFFFF的十六进制值？ 是否有更正确的方法来访问实际的填充颜色？ 谢谢。

Answer 1

“Excel 2013工作簿”是以Office Open XML格式存储的工作簿。 那里的颜色可能有额外的第4个alpha通道，但也可能有ColorType.Tint属性集。 实际上所有灰色阴影都是具有不同tint设置的RGB白色FFFFFF 。 例如，在xl/styles.xml ， Grey 1是：

...
<fill>
 <patternFill patternType="solid">
  <fgColor theme="0" tint="-0.0499893185216834"/>
  <bgColor indexed="64"/>
 </patternFill>
</fill>
...

主题颜色0是白色FFFFFF ， tint -0.0499893185216834变暗，白色变为灰色。

所以我们必须考虑tint 。 Fortunaltely apache poi的ExtendedColor为此提供了方法getRGBWithTint 。

因此，如果它们具有tint集，则以下示例也正确获取填充颜色：

import java.io.FileInputStream;

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

public class ReadExcelColorHavingTint {

 private static String getFillColorHex(Cell cell) throws Exception { 
  String fillColorString = "none";
  if (cell != null) {
   CellStyle cellStyle = cell.getCellStyle();
   Color color =  cellStyle.getFillForegroundColorColor();
   if (color instanceof XSSFColor) {
    XSSFColor xssfColor = (XSSFColor)color;
    byte[] argb = xssfColor.getARGB();
    fillColorString = "[" + (argb[0]&0xFF) + ", " + (argb[1]&0xFF) + ", " + (argb[2]&0xFF) + ", " + (argb[3]&0xFF) + "]";
    if (xssfColor.hasTint()) {
     fillColorString += " * " + xssfColor.getTint();
     byte[] rgb = xssfColor.getRGBWithTint();
     fillColorString += " = [" + (argb[0]&0xFF) + ", " + (rgb[0]&0xFF) + ", " + (rgb[1]&0xFF) + ", " + (rgb[2]&0xFF) + "]" ;
    }
   } else if (color instanceof HSSFColor) {
    HSSFColor hssfColor = (HSSFColor)color;
    short[] rgb = hssfColor.getTriplet();
    fillColorString = "[" + rgb[0] + ", " + rgb[1] + ", "  + rgb[2] + "]";
   }
  }
  return fillColorString;
 }

 public static void main(String[] args) throws Exception {
  Workbook workbook = WorkbookFactory.create(new FileInputStream("workbook.xlsx"));
  //Workbook workbook = WorkbookFactory.create(new FileInputStream("workbook.xls"));
  Sheet sheet = workbook.getSheetAt(0);
  for (Row row : sheet) {
   for (Cell cell : row) {

    System.out.println("Cell=" + cell.getAddress() + " " + cell.toString() + " " + getFillColorHex(cell));

   }
  }
 }

}