When you need to format a number as a percent you can use the ‘%’ symbol in your DecimalFormat string. The static helper method getPercentInstance() can also be used if you don’t need complete control over the format string.
When the % symbol is used the value is first multiplied by 100 before applying the format string. So 0.123 would become 12.3%.
NumberFormat format1 = new DecimalFormat("##.####%");
NumberFormat format2 = NumberFormat.getPercentInstance();
String formatted1 = format1.format(value);
String formatted2 = format2.format(value);
written by objects
\\ tags: BigDecimal, DecimalFormat, double, float, format, NumberFormat, percent
You can use the setScale() method to control the rounding of a decimal value as shown in the following example:
double value = 123.456789;
BigDecimal bd = new BigDecimal(value).setScale(2, BigDecimal.ROUND_HALF_UP);
System.out.println(bd);
written by objects
\\ tags: BigDecimal, decimal, double, rounding
The BigDecimal constructors do not take the Locale into account when parsing number strings.
This means the following code will throw a NumberFormatException
Locale.setDefault(new Locale("nl", "NL"));
String s = "2.343.298,09324798";
BigDecimal bd = new BigDecimal(s);
To parse localized strings as BigDecimal we instead need to use the DecimalFormat class
Locale.setDefault(new Locale("nl", "NL"));
String s = "2.343.298,09324798";
DecimalFormat df = (DecimalFormat) NumberFormat.getInstance();
df.setParseBigDecimal(true);
BigDecimal bd = (BigDecimal) df.parse(s);
written by objects
\\ tags: BigDecimal, DecimalFormat, Locale, NumberFormat, parse