Percent Testing and BigDecimal

Question

I have two BigDecimals Actual and Budgeted. I am sharing Actual Budget to come up with a percentage.

The problem I am facing is that when I build some unit tests, I try to confirm that the resulting BigDecimal is .1, but when try is (the new BigDecimal (.1)), it fails due to double precision problems.

The way I thought about this was to create two BigDecimals - ten and one hundred, separate the two and use them for testing. Thus, I only use fixed-point numbers, and my calculations should work exactly.

So my question is: is there a better way to do this?

Answer 1

When using BigDecimal, you should do tests with "equality of numbers" using the compareTo method instead of the equals method:

 if (bigDecimal1.compareTo(bigDecimal2) == 0) { //then they are equals 

Wed javadoc for more information.

As already mentioned, you should use a string constructor to avoid rounding issues.

Answer 2

You can use the BigDecimal ( document ) string constructor:

  equals( new BigDecimal("0.1") );