Apache POI- Convert Excel column number to letter & Create color using RGB

Recently I had chance generating a complex excel file using Apache POI. I spent a few hours finding formulas.

In this article, I am going to share those formulas.  Hope this will helpful for you.

//Convert excel column number to letter

import org.apache.poi.hssf.util.CellReference

String letter = CellReference.convertNumToColString(ColumnNumber);

// Create color using RGB code

import org.apache.poi.hssf.usermodel.HSSFPalette;

HSSFPalette palette = workbook.getCustomPalette();

palette.setColorAtIndex(new Byte((byte) 10), new Byte((byte) 22), new Byte((byte) 54), new Byte((byte) 92));

//(short index,byte red,byte green, byte blue) - index - the palette index, between 0x8 to 0x40 inclusive

 

HSSFCellStyle worksheetCellStyle = workbook.createCellStyle();

worksheetCellStyle.setFillForegroundColor(palette.getColor(10).getIndex());