I recommend not to use the BigDecimal(double) constructor. Because of floating point imprecision, we're unlikely to get the value we expect from that constructor.
Instead, we should use BigDecimal.valueOf, which uses a string under the covers to eliminate floating-point rounding errors, or the constructor that takes a String argument.
The results of this constructor can be somewhat unpredictable. One might assume that writing new BigDecimal(0.1) in Java creates a BigDecimal which is exactly equal to 0.1 (an unscaled value of 1, with a scale of 1), but it is actually equal to 0.1000000000000000055511151231257827021181583404541015625. This is because 0.1 cannot be represented exactly as a double (or, for that matter, as a binary fraction of any finite length). Thus, the value that is being passed in to the constructor is not exactly equal to 0.1, appearances notwithstanding.