Java, extract just the fractional part of a BigDecimal?

Solution 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

Solution 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

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

bd = bd.stripTrailingZeros();

before the previous code.