I have a project which converts HTML/CSS to various formats including Excel and ODF. If it's of any use, I do the following where Style is a class holding the various properties extracted from the CSS.
public class ExcelStyleGenerator {
private Map<Style, XSSFCellStyle> styles;
public ExcelStyleGenerator() {
styles = new HashMap<Style, XSSFCellStyle>();
}
public CellStyle getStyle(Cell cell, Style style) {
XSSFCellStyle cellStyle;
if (styles.containsKey(style)) {
cellStyle = styles.get(style);
} else {
cellStyle = (XSSFCellStyle) cell.getSheet().getWorkbook().createCellStyle();
applyBackground(style, cellStyle);
applyBorders(style, cellStyle);
applyFont(cell, style, cellStyle);
applyHorizontalAlignment(style, cellStyle);
applyverticalAlignment(style, cellStyle);
applyWidth(cell, style);
styles.put(style, cellStyle);
}
return cellStyle;
}
protected void applyBackground(Style style, XSSFCellStyle cellStyle) {
if (style.isBackgroundSet()) {
cellStyle.setFillPattern(XSSFCellStyle.SOLID_FOREGROUND);
cellStyle.setFillForegroundColor(new XSSFColor(style.getProperty(CssColorProperty.BACKGROUND)));
}
}
protected void applyBorders(Style style, XSSFCellStyle cellStyle) {
if (style.isBorderWidthSet()) {
short width = (short) style.getProperty(CssIntegerProperty.BORDER_WIDTH);
Color color = style.getProperty(CssColorProperty.BORDER_COLOR) != null ? style
.getProperty(CssColorProperty.BORDER_COLOR) : Color.BLACK;
cellStyle.setBorderBottom(BorderStyle.THIN);
cellStyle.setBorderBottom(width);
cellStyle.setBottomBorderColor(new XSSFColor(color));
cellStyle.setBorderTop(BorderStyle.THIN);
cellStyle.setBorderTop(width);
cellStyle.setTopBorderColor(new XSSFColor(color));
cellStyle.setBorderLeft(BorderStyle.THIN);
cellStyle.setBorderLeft(width);
cellStyle.setLeftBorderColor(new XSSFColor(color));
cellStyle.setBorderRight(BorderStyle.THIN);
cellStyle.setBorderRight(width);
cellStyle.setRightBorderColor(new XSSFColor(color));
}
}
protected void applyFont(Cell cell, Style style, XSSFCellStyle cellStyle) {
Font font = createFont(cell.getSheet().getWorkbook(), style);
cellStyle.setFont(font);
}
protected void applyHorizontalAlignment(Style style, XSSFCellStyle cellStyle) {
if (style.isHorizontallyAlignedLeft()) {
cellStyle.setAlignment(HorizontalAlignment.LEFT);
} else if (style.isHorizontallyAlignedRight()) {
cellStyle.setAlignment(HorizontalAlignment.RIGHT);
} else if (style.isHorizontallyAlignedCenter()) {
cellStyle.setAlignment(HorizontalAlignment.CENTER);
}
}
protected void applyverticalAlignment(Style style, XSSFCellStyle cellStyle) {
if (style.isVerticallyAlignedTop()) {
cellStyle.setVerticalAlignment(VerticalAlignment.TOP);
} else if (style.isVerticallyAlignedBottom()) {
cellStyle.setVerticalAlignment(VerticalAlignment.BOTTOM);
} else if (style.isVerticallyAlignedMiddle()) {
cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
}
}
protected void applyWidth(Cell cell, Style style) {
if (style.getProperty(CssIntegerProperty.WIDTH) > 0) {
cell.getSheet().setColumnWidth(cell.getColumnIndex(), style.getProperty(CssIntegerProperty.WIDTH) * 50);
}
}
public Font createFont(Workbook workbook, Style style) {
Font font = workbook.createFont();
if (style.isFontNameSet()) {
font.setFontName(style.getProperty(CssStringProperty.FONT_FAMILY));
}
if (style.isFontSizeSet()) {
font.setFontHeightInPoints((short) style.getProperty(CssIntegerProperty.FONT_SIZE));
}
if (style.isColorSet()) {
Color color = style.getProperty(CssColorProperty.COLOR);
// if(! color.equals(Color.WHITE)) // POI Bug
// {
((XSSFFont) font).setColor(new XSSFColor(color));
// }
}
if (style.isFontBold()) {
font.setBoldweight(Font.BOLDWEIGHT_BOLD);
}
font.setItalic(style.isFontItalic());
if (style.isTextUnderlined()) {
font.setUnderline(Font.U_SINGLE);
}
return font;
}
}