Java中高精度计算的实现（bigDecimal类）

骑猪看日落 2022-05-27 12:20 293阅读 0赞

java中默认的计算是不支持很精确的小数位运算，但是使用bigDecimal类的方法可以解决此问题。

下面是我在项目中封装的一个工具类。供大家参考

/**
     * 高精度计算工具类
     *
     * @author Leon
     * @version 2018/4/18 11:56
     */
    public class ArithmeticUtil {
    
        /**
         * default divide scale
         */
        private static final int DEFAULT_DIVIDE_SCALE = 10;
    
        /**
         *default add scale
         */
        private static final int DEFAULT_ADD_SCALE = 4;
    
        /**
         *default subtract scale
         */
        private static final int DEFAULT_SUB_SCALE = 4;
    
        /**
         * default multiplicative default
         */
        private static final int DEFAULT_MULTI_SCALE = 10;
    
        /**
         * default scale
         */
        private static final int DEFAULT_SCALE = 2;
    
        /**
         * private constructor
         */
        private ArithmeticUtil(){}
    
        /**
         * Return the result of tow number divide by default scale
         *
         * @param arg1
         * @param arg2
         * @return
         */
        public static double divide(double arg1, double arg2){
            return divide(arg1, arg2, DEFAULT_DIVIDE_SCALE);
        }
    
        /**
         * Return the result of two string number divide by scale
         *
         * @param arg1
         * @param arg2
         * @param scale
         * @return
         */
        public static double divide(double arg1, double arg2, int scale){
            return divide(Double.toString(arg1), Double.toString(arg2), scale);
        }
    
        /**
         * Return the result of two string number divide by default scale
         *
         * @param arg1
         * @param arg2
         * @return
         */
        public static double divide(String arg1, String arg2){
            return divide(arg1, arg2,DEFAULT_DIVIDE_SCALE);
        }
    
        /**
         * Return the result of two string number divide by scale
         *
         * @param arg1
         * @param arg2
         * @param scale
         * @return
         */
        public static double divide(String arg1, String arg2, int scale){
            BigDecimal var1 = new BigDecimal(arg1);
            BigDecimal var2 = new BigDecimal(arg2);
            return var1.divide(var2, scale, BigDecimal.ROUND_HALF_UP).doubleValue();
        }
    
        /**
         * Return the result of two number multiplicative by default scale
         *
         * @param arg1
         * @param arg2
         * @return
         */
        public static double multiply(double arg1, double arg2){
            return multiply(arg1, arg2, DEFAULT_MULTI_SCALE);
        }
    
        /**
         * Return the result of two number multiplicative by scale
         *
         * @param arg1
         * @param arg2
         * @return
         */
        public static double multiply(double arg1, double arg2, int scale){
            return multiply(Double.toString(arg1), Double.toString(arg2), scale);
        }
    
        /**
         * Return the result two string number multiplicative by default scale
         *
         * @param arg1
         * @param arg2
         * @return
         */
        public static double multiply(String arg1, String arg2){
            return multiply(arg1, arg2, DEFAULT_MULTI_SCALE);
        }
    
        /**
         * Return the result of two number multiplicative by scale
         *
         * @param arg1
         * @param arg2
         * @param scale
         * @return
         */
        public static double multiply(String arg1, String arg2, int scale){
            BigDecimal var1 = new BigDecimal(arg1);
            BigDecimal var2 = new BigDecimal(arg2);
            return round(var1.multiply(var2).doubleValue(), scale);
        }
    
        /**
         * Return the result of two number subtract by scale
         *
         * @param arg1
         * @param arg2
         * @param scale
         * @return
         */
        public static double subtract(double arg1, double arg2 ,int scale){
            return subtract(Double.toString(arg1), Double.toString(arg2), scale);
        }
    
        /**
         * Return the result of two number subtract by default scale
         *
         * @param arg1
         * @param arg2
         * @return
         */
        public static double subtract(double arg1, double arg2){
            return subtract(Double.toString(arg1), Double.toString(arg2), DEFAULT_SUB_SCALE);
        }
        /**
         * Return the result of two number subtract by default scale
         *
         * @param arg1
         * @param arg2
         * @return
         */
        public static double subtract(String arg1, String arg2){
            return subtract(arg1, arg2, DEFAULT_SUB_SCALE);
        }
    
        /**
         * Return the result of two number subtract by scale
         *
         * @param arg1
         * @param arg2
         * @param scale
         * @return
         */
        public static double subtract(String arg1, String arg2, int scale){
            BigDecimal var1 = new BigDecimal(arg1);
            BigDecimal var2 = new BigDecimal(arg2);
            return round(var1.subtract(var2).doubleValue(), scale);
        }
    
        /**
         * Return two number sum by the param scale value
         *
         * @param arg1
         * @param arg2
         * @param scale
         * @return
         */
        public static double add(double arg1, double arg2, int scale){
            return add(Double.toString(arg1), Double.toString(arg2), scale);
        }
    
        /**
         * Return two number sum by default add scale
         *
         * @param arg1
         * @param arg2
         * @return
         */
        public static double add(double arg1, double arg2){
            return add(Double.toString(arg1), Double.toString(arg2));
        }
    
        /**
         * Return two number sum by default add scale
         *
         * @param arg1
         * @param arg2
         * @return
         */
        public static double add(String arg1, String arg2){
            return add(arg1, arg2, DEFAULT_ADD_SCALE);
        }
    
        /**
         * Return two number sum by scale
         *
         * @param arg1
         * @param arg2
         * @param scale
         * @return
         */
        public static double add(String arg1, String arg2, int scale){
            BigDecimal var1 = new BigDecimal(arg1);
            BigDecimal var2 = new BigDecimal(arg2);
            return round(var1.add(var2).doubleValue(), scale);
        }
    
        /**
         * Return a result from arg1 by scale
         *
         * @param arg1
         * @param scale
         * @return
         */
        public static double round(double arg1, int scale){
            return round(Double.toString(arg1), scale);
        }
    
        /**
         * Return result by scale
         *
         * @param arg1
         * @param scale
         * @return
         */
        public static double round(String arg1, int scale){
            if (scale < 0){
                throw new IllegalArgumentException("The scale value must be an integer or zero");
            }
            BigDecimal var1 = new BigDecimal(arg1);
            BigDecimal var2 = new BigDecimal(1);
            return var1.divide(var2, scale, BigDecimal.ROUND_HALF_UP).doubleValue();
        }
    
        /**
         * Return a result from arg1 by default scale
         *
         * @param arg1
         * @return
         */
        public static double round(double arg1){
            return round(arg1, DEFAULT_SCALE);
        }
    
    }