POI excel percentage

The two methods ：

One 、 String splicing ：“20.36”+“%”,

                 Simple and direct ;

                 The disadvantage is that , Generated Excel You cannot directly create a statistical chart ( Not numbers , Manual format conversion required )

Two 、 Use POI Cell style ：

//  Create styles 
HSSFCellStyle cellStyle2 = workbook.createCellStyle();
//  Cell data format 
cellStyle2.setDataFormat(workbook.createDataFormat().getFormat("0.00%"));

Here is the complete code （ Unit tests can be used directly ）：

    @org.junit.Test
    public void exportExcel() throws IOException {
        HSSFWorkbook workbook = new HSSFWorkbook();
        //  Set the font 
        HSSFFont font2 = workbook.createFont();
        //  Font height 
        font2.setFontHeightInPoints((short) 11);
        //  The font color 
        font2.setColor(HSSFFont.COLOR_NORMAL);

        //  Create styles 
        HSSFCellStyle cellStyle2 = workbook.createCellStyle();
        cellStyle2.setFont(font2);
        //  Horizontal layout ： In the middle 
        cellStyle2.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        //  Vertical center 
        cellStyle2.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
        //  Cell color 
        cellStyle2.setFillForegroundColor(HSSFColor.ORANGE.index);
        //  Fill cell colors 
        cellStyle2.setFillPattern((short) 1);
        //  Cell data format 
        cellStyle2.setDataFormat(workbook.createDataFormat().getFormat("0.00%"));

        //  data 
        int a = 99;
        double b = 101;
        double rate = a / b;
        rate = new BigDecimal(rate).setScale(4,BigDecimal.ROUND_HALF_UP).doubleValue();

        //  Generate Excel
        HSSFSheet sheet = workbook.createSheet("sheet");
        HSSFRow row = sheet.createRow(0);
        row.createCell(0).setCellValue(" Proportion ");
        row.createCell(1).setCellValue(rate);
        row.getCell(1).setCellStyle(cellStyle2);

        //  Output Excel
        String filePath = "D://abc.xls";
        FileOutputStream fout = new FileOutputStream(filePath);
        workbook.write(fout);
        fout.close();
    }

design sketch ：