Using BigDecimal

The BigDecimal class, which is a member of the java.math library, is a fixed-precision representation of floating point numbers. This means that values represented as BigDecimal do not suffer from the problem of approximation that can and does occur when calculations are carried out by the hardware floating point unit (FPU) of most CPUs.

The BigDecimal class shares an important characteristic with a string. They are both immutable. This means that when a value becomes a BigDecimal object, it cannot be changed. Any operation on a BigDecimal object returns a new BigDecimal object.

Let us look at an application that can calculate loan payments for money borrowed. The formula for this calculation is as follows:

Here:

• rate = the interest rate per period
• n = the number of periods
• PV = present value (amount of loan)
• PMT = payment (the monthly payment)

If we use doubles for all the values, the Java bean data object...