JAVA 计算百分比

/**
     * 计算百分比 默认保留两位
     * @param diliverNum 被除数
     * @param queryMailNum 除数
     * @return
     */
    public static String percentageStr(double diliverNum,double queryMailNum){
        return percentageStr(diliverNum,queryMailNum,2);
    }

    /**
     * 计算百分比
     * @param diliverNum 被除数
     * @param queryMailNum 除数
     * @param radixPoint 保留小数点位数
     * @return
     */
    public static String percentageStr(double diliverNum,double queryMailNum,int radixPoint){
        // 创建一个数值格式化对象
        NumberFormat numberFormat = NumberFormat.getInstance();
        // 设置精确到小数点后radixPoint位
        numberFormat.setMaximumFractionDigits(radixPoint);
        String result = numberFormat.format(diliverNum/queryMailNum*100);
        return result;
    }
    public static double percentage(double diliverNum,double queryMailNum){
        return percentage(diliverNum,queryMailNum,2);
    }

    public static double percentage(double diliverNum,double queryMailNum,int radixPoint){
        // 创建一个数值格式化对象
        NumberFormat numberFormat = NumberFormat.getInstance();
        // 设置精确到小数点后radixPoint位
        numberFormat.setMaximumFractionDigits(radixPoint);
        String result = numberFormat.format(diliverNum/queryMailNum*100);
        return Double.valueOf(result);
    }