public class PercentCount {
    /**
     * @param preNum 当前期
     * @param sufNum 标准值
     * @return 返回百分比
     */
    public double percentBigDecimal(BigDecimal preNum, BigDecimal sufNum) {
        double result = countDecimal(preNum, sufNum);
//        if (result > 0) {
//            return "+" + result + "%";
//        }
//        if (result < 0) {
//            return result + "%";
//        }
//        if (result == 0) {
//            return "+" + 0 + "%";
//        }
//        return null;
        return result;
    }

    public double countDecimal(BigDecimal preNum, BigDecimal sufNum) {
        boolean preBoolean = verifyNum(preNum);
        boolean sufBoolean = verifyNum(sufNum);
        //同时为true计算
        if (preBoolean && sufBoolean) {
            boolean b = verifyEqual(preNum, sufNum);
            if (!b) {
                return realCountDecimal(preNum, sufNum);
            }
            if (b) {
                return 0;
            }
        }
        if (!preBoolean && !sufBoolean) {
            return 0;
        }
        if (!sufBoolean) {
            return 100;
        }
        return 0;
    }

    //验证数字是否为零和null
    public boolean verifyNum(BigDecimal num) {
        if (null != num && num.compareTo(BigDecimal.ZERO) != 0) {
            return true;
        }
        return false;
    }

    //验证两个数字是否相等
    public boolean verifyEqual(BigDecimal preNum, BigDecimal sufNum) {
        int n = preNum.compareTo(sufNum);
        //比较 -1 小于   0 等于    1 大于
        if (n == 0) {
            return true;
        }
        return false;
    }

    //真正计算
    public double realCountDecimal(BigDecimal preNum, BigDecimal sufNum) {
        //(前面的数字-后面的数字)/后面的数字*100
        BigDecimal bigDecimal = (preNum.subtract(sufNum)).divide(sufNum, 2, BigDecimal.ROUND_HALF_UP)
                .multiply(new BigDecimal("100"));
        if (bigDecimal.compareTo(BigDecimal.ZERO) != 0) {
            return bigDecimal.doubleValue();
        }
        return 0;
    }

    public static void main(String[] args) {
        PercentCount p = new PercentCount();
        BigDecimal a = new BigDecimal("1");
        BigDecimal b = new BigDecimal("1.1");
        double percent = p.percentBigDecimal(a, b);
        System.out.println(percent);
        double result = (percent / 1);
        System.out.println("初始值:"+result);

        if (result >= 10) {
            System.out.println(result);
        } else {
            result = result * 0.5 + 40;
            System.out.println(result);
        }


    }

}