How to Print Formatted BigDecimal Values in Java

Question

How can I print formatted BigDecimal values as currency in Java?

import java.math.BigDecimal;
import java.text.NumberFormat;

public class Main {
    public static void main(String[] args) {
        BigDecimal amount = new BigDecimal("123.45");
        String formattedAmount = formatCurrency(amount);
        System.out.println(formattedAmount);
    }

    public static String formatCurrency(BigDecimal value) {
        NumberFormat currencyFormat = NumberFormat.getCurrencyInstance();
        return currencyFormat.format(value);
    }
}

Answer

In Java, formatting a BigDecimal to display as currency can be achieved using the NumberFormat class. This approach provides a straightforward way to ensure proper currency representation without losing the precision that BigDecimal offers.

import java.math.BigDecimal;
import java.text.NumberFormat;

public class CurrencyFormatter {
    public static void main(String[] args) {
        BigDecimal amount = new BigDecimal("123.456"); // Sample amount
        System.out.println(formatBigDecimalAsCurrency(amount));
    }

    public static String formatBigDecimalAsCurrency(BigDecimal value) {
        value = value.setScale(2, BigDecimal.ROUND_HALF_UP); // Set scale to 2 decimal places
        NumberFormat currencyFormatter = NumberFormat.getCurrencyInstance(); // Get Currency Instance
        return currencyFormatter.format(value); // Format BigDecimal
    }
}

Causes

Incorrect handling of currency formatting may lead to loss of precision.
Using float or double values can introduce rounding errors.

Solutions

Utilize the NumberFormat class from java.text to format BigDecimal values.
Call the setScale method on BigDecimal to define the number of decimal places explicitly.

Common Mistakes

Mistake: Using floatValue from BigDecimal for formatting.

Solution: Use the BigDecimal directly without converting to float, as it can lead to precision loss.

Mistake: Not setting scale when formatting currency values.

Solution: Ensure you set the scale of the BigDecimal to 2 decimal places before formatting.

Helpers

Java BigDecimal formatting
format currency BigDecimal Java
Java print currency
BigDecimal number format
Java money format