/** Create a library of cell styles */
private static Map<String, CellStyle> createStyles(Workbook wb) {
Map<String, CellStyle> styles = new HashMap<String, CellStyle>();
CellStyle style;
Font titleFont = wb.createFont();
titleFont.setFontHeightInPoints((short) 18);
titleFont.setBoldweight(Font.BOLDWEIGHT_BOLD);
style = wb.createCellStyle();
style.setAlignment(CellStyle.ALIGN_CENTER);
style.setVerticalAlignment(CellStyle.VERTICAL_CENTER);
style.setFont(titleFont);
styles.put("title", style);
Font monthFont = wb.createFont();
monthFont.setFontHeightInPoints((short) 11);
monthFont.setColor(IndexedColors.WHITE.getIndex());
style = wb.createCellStyle();
style.setAlignment(CellStyle.ALIGN_CENTER);
style.setVerticalAlignment(CellStyle.VERTICAL_CENTER);
style.setFillForegroundColor(IndexedColors.GREY_50_PERCENT.getIndex());
style.setFillPattern(CellStyle.SOLID_FOREGROUND);
style.setFont(monthFont);
style.setWrapText(true);
styles.put("header", style);
style = wb.createCellStyle();
style.setAlignment(CellStyle.ALIGN_CENTER);
style.setWrapText(true);
style.setBorderRight(CellStyle.BORDER_THIN);
style.setRightBorderColor(IndexedColors.BLACK.getIndex());
style.setBorderLeft(CellStyle.BORDER_THIN);
style.setLeftBorderColor(IndexedColors.BLACK.getIndex());
style.setBorderTop(CellStyle.BORDER_THIN);
style.setTopBorderColor(IndexedColors.BLACK.getIndex());
style.setBorderBottom(CellStyle.BORDER_THIN);
style.setBottomBorderColor(IndexedColors.BLACK.getIndex());
styles.put("cell", style);
style = wb.createCellStyle();
style.setAlignment(CellStyle.ALIGN_CENTER);
style.setVerticalAlignment(CellStyle.VERTICAL_CENTER);
style.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.getIndex());
style.setFillPattern(CellStyle.SOLID_FOREGROUND);
style.setDataFormat(wb.createDataFormat().getFormat("0.00"));
styles.put("formula", style);
style = wb.createCellStyle();
style.setAlignment(CellStyle.ALIGN_CENTER);
style.setVerticalAlignment(CellStyle.VERTICAL_CENTER);
style.setFillForegroundColor(IndexedColors.GREY_40_PERCENT.getIndex());
style.setFillPattern(CellStyle.SOLID_FOREGROUND);
style.setDataFormat(wb.createDataFormat().getFormat("0.00"));
styles.put("formula_2", style);
return styles;
}