Hi evetyone, I'm working with the 3.8 version of POI and have problem when I try to set the Diagonal border of a cell it doesn't appear Below is the sample code: HSSFWorkbook wb = new HSSFWorkbook(); HSSFSheetConditionalFormatting scf = wb.createSheet("Page 1").getSheetConditionalFormatting(); HSSFConditionalFormattingRule rule = scf.createConditionalFormattingRule(ComparisonOperator.GT, "10"); HSSFFontFormatting font = rule.createFontFormatting(); font.setStrikeout(true); HSSFBorderFormatting bord = rule.createBorderFormatting(); bord.setBorderDiagonal(BorderFormatting.BORDER_THICK); bord.setBorderBottom(BorderFormatting.BORDER_THICK); bord.setBottomBorderColor((short)30); bord.setDiagonalBorderColor((short)30); CellRangeAddress[] cra = {new CellRangeAddress(1, 3, 0, 3)}; scf.addConditionalFormatting(cra, rule); Thanks for your help.
I added a unit test for this in r1753359. This is still failing in POI 3.15 beta 2+, at least as far as I've been able to test with LibreOffice. One thing your test case was likely missing was border.setForwardDiagonalOn(true), since setting the border thickness and color isn't enough to turn on the diagonal borders.