The Java Formatter's format() method accepts a wide variety of format specifiers.
Many specifiers have both upper- and lowercase forms.
When an uppercase specifier is used, then letters are shown in uppercase.
Otherwise, the upper- and lowercase specifiers do the same conversion.
| Format Specifier | Conversion Applied |
|---|---|
| %a %A | Floating-point hexadecimal |
| %b %B | Boolean |
| %c | Character |
| %d | Decimal integer |
| %h %H | Hash code of the argument |
| %e %E | Scientific notation |
| %f | Decimal floating-point |
| %g %G | Uses %e or %f, based on the value being formatted and the precision |
| %o | Octal integer |
| %n | Inserts a newline character |
| %s %S | String |
| %t %T | Time and date |
| %x %X | Integer hexadecimal |
| %% | Inserts a % sign |
Java type-checks each format specifier against its corresponding argument.
If the argument doesn't match, an IllegalFormatException is thrown.
To get the formatted string, call toString().
String str = fmt.toString();
To get a reference to the underlying output buffer, call out().
It returns a reference to an Appendable object.