EasyExcel导出保留2位小数

        对于百分率导出，可以用SQL解决，生成为保留2位数的字符串，但是这样导出后单元格格式就变为了文本，不理想。

        更为理想的解决方法：利用EasyExcel的注解@ContentStyle，具体如下：

    /**
     * 完成率
     */
    @ExcelProperty(value = "完成率", index = 1)
    @ContentStyle(dataFormat = 2)
    private Double completeRate;

    ......

        这个注解的dataFormat就是设置格式的，他的值是BuiltinFormats类中BUILTIN_FORMATS_XX数组中对应格式的下标，源码如下：

public class BuiltinFormats {
    private static final String[] BUILTIN_FORMATS_CN = new String[]{"General", "0", "0.00", "#,##0", "#,##0.00", "\"￥\"#,##0_);(\"￥\"#,##0)", "\"￥\"#,##0_);[Red](\"￥\"#,##0)", "\"￥\"#,##0.00_);(\"￥\"#,##0.00)", "\"￥\"#,##0.00_);[Red](\"￥\"#,##0.00)", "0%", "0.00%", "0.00E+00", "# ?/?", "# ??/??", "yyyy/m/d", "d-mmm-yy", "d-mmm", "mmm-yy", "h:mm AM/PM", "h:mm:ss AM/PM", "h:mm", "h:mm:ss", "yyyy-m-d h:mm", null, null, null, null, "yyyy\"年\"m\"月\"", "m\"月\"d\"日\"", "m\"月\"d\"日\"", "m-d-yy", "yyyy\"年\"m\"月\"d\"日\"", "h\"时\"mm\"分\"", "h\"时\"mm\"分\"ss\"秒\"", "上午/下午h\"时\"mm\"分\"", "上午/下午h\"时\"mm\"分\"ss\"秒\"", "yyyy\"年\"m\"月\"", "#,##0_);(#,##0)", "#,##0_);[Red](#,##0)", "#,##0.00_);(#,##0.00)", "#,##0.00_);[Red](#,##0.00)", "_(* #,##0_);_(* (#,##0);_(* \"-\"_);_(@_)", "_(\"￥\"* #,##0_);_(\"￥\"* (#,##0);_(\"￥\"* \"-\"_);_(@_)", "_(* #,##0.00_);_(* (#,##0.00);_(* \"-\"??_);_(@_)", "_(\"￥\"* #,##0.00_);_(\"￥\"* (#,##0.00);_(\"￥\"* \"-\"??_);_(@_)", "mm:ss", "[h]:mm:ss", "mm:ss.0", "##0.0E+0", "@", "yyyy\"年\"m\"月\"", "m\"月\"d\"日\"", "yyyy\"年\"m\"月\"", "m\"月\"d\"日\"", "m\"月\"d\"日\"", "上午/下午h\"时\"mm\"分\"", "上午/下午h\"时\"mm\"分\"ss\"秒\"", "yyyy\"年\"m\"月\"", "m\"月\"d\"日\"", "t0", "t0.00", "t#,##0", "t#,##0.00", null, null, null, null, "t0%", "t0.00%", "t# ?/?", "t# ??/??", "ว/ด/ปปปป", "ว-ดดด-ปป", "ว-ดดด", "ดดด-ปป", "ช:นน", "ช:นน:ทท", "ว/ด/ปปปป ช:นน", "นน:ทท", "[ช]:นน:ทท", "นน:ทท.0", "d/m/bb"};
    private static final String[] BUILTIN_FORMATS_US = new String[]{"General", "0", "0.00", "#,##0", "#,##0.00", "\"$\"#,##0_);(\"$\"#,##0)", "\"$\"#,##0_);[Red](\"$\"#,##0)", "\"$\"#,##0.00_);(\"$\"#,##0.00)", "\"$\"#,##0.00_);[Red](\"$\"#,##0.00)", "0%", "0.00%", "0.00E+00", "# ?/?", "# ??/??", "yyyy/m/d", "d-mmm-yy", "d-mmm", "mmm-yy", "h:mm AM/PM", "h:mm:ss AM/PM", "h:mm", "h:mm:ss", "yyyy-m-d h:mm", null, null, null, null, "yyyy\"年\"m\"月\"", "m\"月\"d\"日\"", "m\"月\"d\"日\"", "m-d-yy", "yyyy\"年\"m\"月\"d\"日\"", "h\"时\"mm\"分\"", "h\"时\"mm\"分\"ss\"秒\"", "上午/下午h\"时\"mm\"分\"", "上午/下午h\"时\"mm\"分\"ss\"秒\"", "yyyy\"年\"m\"月\"", "#,##0_);(#,##0)", "#,##0_);[Red](#,##0)", "#,##0.00_);(#,##0.00)", "#,##0.00_);[Red](#,##0.00)", "_(* #,##0_);_(* (#,##0);_(* \"-\"_);_(@_)", "_(\"$\"* #,##0_);_(\"$\"* (#,##0);_(\"$\"* \"-\"_);_(@_)", "_(* #,##0.00_);_(* (#,##0.00);_(* \"-\"??_);_(@_)", "_(\"$\"* #,##0.00_);_(\"$\"* (#,##0.00);_(\"$\"* \"-\"??_);_(@_)", "mm:ss", "[h]:mm:ss", "mm:ss.0", "##0.0E+0", "@", "yyyy\"年\"m\"月\"", "m\"月\"d\"日\"", "yyyy\"年\"m\"月\"", "m\"月\"d\"日\"", "m\"月\"d\"日\"", "上午/下午h\"时\"mm\"分\"", "上午/下午h\"时\"mm\"分\"ss\"秒\"", "yyyy\"年\"m\"月\"", "m\"月\"d\"日\"", "t0", "t0.00", "t#,##0", "t#,##0.00", null, null, null, null, "t0%", "t0.00%", "t# ?/?", "t# ??/??", "ว/ด/ปปปป", "ว-ดดด-ปป", "ว-ดดด", "ดดด-ปป", "ช:นน", "ช:นน:ทท", "ว/ด/ปปปป ช:นน", "นน:ทท", "[ช]:นน:ทท", "นน:ทท.0", "d/m/bb"};

    public BuiltinFormats() {
    }

    public static String getBuiltinFormat(Integer index, String defaultFormat, Locale locale) {
        String[] builtinFormat = switchBuiltinFormats(locale);
        return index != null && index >= 0 && index < builtinFormat.length ? builtinFormat[index] : defaultFormat;
    }

    private static String[] switchBuiltinFormats(Locale locale) {
        return locale != null && Locale.US.getCountry().equals(locale.getCountry()) ? BUILTIN_FORMATS_US : BUILTIN_FORMATS_CN;
    }
}

        我需要保留2位小数就选0.00，对应下标2。

        这个注解有不少属性，感觉用处蛮大，这次没时间，下次试试其他属性。

        EasyExcel不少注解可以用，我也是看的源码找到上面的这个注解来用的：

         时间紧张，结束！