double nan java,Java：BigDecimal和Double.NaN

I am trying to execute following code:

import java.math.*;

public class HelloWorld{

public static void main(String []args){

System.out.println(BigDecimal.valueOf(Double.NaN));

}

}

And reasonably, I am getting:

Exception in thread "main" java.lang.NumberFormatException

at java.math.BigDecimal.(BigDecimal.java:470)

at java.math.BigDecimal.(BigDecimal.java:739)

at java.math.BigDecimal.valueOf(BigDecimal.java:1069)

at HelloWorld.main(HelloWorld.java:6)

Is there a way to represent Double.NaN in BigDecimal?

解决方案

Is there a way to represent Double.NaN in BigDecimal?

No. The BigDecimal class provides no representation for NaN, +∞ or -∞.

You might consider using null ... except that you need at least 3 distinct null values to represent the 3 possible cases, and that is not possible.

You could consider creating a subclass of BigDecimal that handles these "special" values, but it may be simpler to implement your "numbers" as a wrapper for BigDecimal, and treat NaN and the like as special cases; e.g.

public class MyNumber {

private BigDecimal value;

private boolean isNaN;

...

private MyNumber(BigDecimal value, boolean isNaN) {

this.value = value;

this.isNaN = isNan;

}

public MyNumber multiply(MyNumber other) {

if (this.isNaN || other.isNaN) {

return new MyNumber(null, true);

} else {

return new MyNumber(this.value.multiply(other.value), false);

}

}

// etcetera

}