Rounding BigDecimal to always have two decimal places
You can round a BigDecimal to two decimal places using setScale(2, RoundingMode.HALF_UP). This function ensures precision up to two decimal points, rounding up from .005.
After rounding, rounded becomes 123.46.
But if you want to always round up, regardless of the decimal, use RoundingMode.CEILING:
Now, roundedUp equals 123.46, CEILING ensure the value always rounds up.
Tactics for BigDecimal rounding
When playing around with BigDecimal rounding, you can choose from multiple strategies based on your needs.
Half-Up Rounding with setScale
The HALF_UP rounding mode is widely used, and it works just like the round-off method you learned and maybe forgotten in school!
Upward rounding using RoundingMode.CEILING
In scenarios where you want to always round up, choose CEILING. This strategy is particularly useful in financial calculations, where undercharging might cost you a lucrative deal!
Mind the significant digits
The number of significant digits in the BigDecimal comes into play when rounding. For a large number of significant digits, rounding can create quite a difference. So, mind the digits!
Dare to look beyond
Sometimes, native Java methods might not do the trick. In such cases, take refuge in third-party libraries or classes that offer better precision control.
Advanced BigDecimal rounding
Unpredictable scales? No problem!
Dealing with values that have a varying number of decimal points? Keep calm and use the setScale method to standardize them to two decimal points. This will ensure consistency in your numeric formats across the application.
Zero-padding
Need to show two decimals at all times? BigDecimal has got you covered with automatic zero-padding:
In the above example, exactTwo will display as 123.00, fulfilling the two decimal places requirement.
Underflow and overflow handling
Beware of underflow or overflow while performing arithmetic operations with large scale BigDecimal values. Always implement overflow and underflow checks to prevent ArithmeticException or data loss.
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