Java, extract just the fractional part of a BigDecimal?

Question

In Java, I'm working with the BigDecimal class and part of my code requires me to extract the fractional part from it. BigDecimal does not appear to have any built in methods to help me get the number after the decimal point of a BigDecimal.

For example:

BigDecimal bd = new BigDecimal("23452.4523434"); 

I want to extract the 4523434 from the number represented above. What's the best way to do it?

Answer 1

I would try bd.remainder(BigDecimal.ONE).

Uses the remainder method and the ONE constant.

BigDecimal bd = new BigDecimal( "23452.4523434" ); BigDecimal fractionalPart = bd.remainder( BigDecimal.ONE ); // Result:  0.4523434 

Answer 2

If the value is negative, using bd.subtract() will return a wrong decimal.

Use this:

BigInteger decimal = bd.remainder(BigDecimal.ONE).movePointRight(bd.scale()).abs().toBigInteger(); 

It returns 4523434 for 23452.4523434 or -23452.4523434

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In addition, if you don't want extra zeros on the right of the fractional part, use:

bd = bd.stripTrailingZeros(); 

before the previous code.