import java.text.DecimalFormat; public class Main { public static void main(String[] argv) throws Exception { DecimalFormat formatter = new DecimalFormat("00.00E0"); String s = formatter.format(-1234.567); // -12.35E2 System.out.println(s); s = formatter.format(-.1234567); // -12.35E-2 System.out.println(s); } }