How to convert from float to bigDecimal in java?

问题

回答1:

BigDecimal value = new BigDecimal(Float.toString(123.4f));

From the javadocs, the string constructor is generally the preferred way to convert a float into a BigDecimal, as it doesn't suffer from the unpredictability of the BigDecimal(double) constructor.

Quote from the docs:

Note: For values other float and double NaN and ±Infinity, this constructor is compatible with the values returned by Float.toString(float) and Double.toString(double). This is generally the preferred way to convert a float or double into a BigDecimal, as it doesn't suffer from the unpredictability of the BigDecimal(double) constructor.

回答2:

float f = 45.6f;
BigDecimal bd = BigDecimal.valueOf(f);

Quote from documentations:

Note: This is generally the preferred way to convert a double (or float) into a BigDecimal, as the value returned is equal to that resulting from constructing a BigDecimal from the result of using Double.toString(double).

Reference: BigDecimal (Java Platform SE 6)

回答3:

For a precision of 3 digits after the decimal point:

BigDecimal value = new BigDecimal(f,
        new MathContext(3, RoundingMode.HALF_EVEN));

回答4:

This is upto my knowledge :

   public static BigDecimal floatToBigDecimal(Float a){


    if(a == null || a.isInfinite() || a.isNaN()){
        return BigDecimal.ZERO;
    }
    try{
        return BigDecimal.valueOf(a);

    }catch(Exception e){
        return BigDecimal.ZERO;
    }

}

*Note:This is generally the preferred way to convert a double (or float) into a BigDecimal, as the value returned is equal to that resulting from constructing a BigDecimal from the result of using Double.toString(double).

public static BigDecimal valueOf(double val)

Parameters:
val - double to convert to a BigDecimal.
Returns:
a BigDecimal whose value is equal to or approximately equal to the value of val.
Throws:
NumberFormatException - if val is infinite or NaN.
Since:
1.5

I have checked whether Infinite or Not a Number, so that there is less chances of NumberFormatException

来源：https://stackoverflow.com/questions/3829029/how-to-convert-from-float-to-bigdecimal-in-java

标签

java

floating-point

bigdecimal