Java IO.pdf - Nguyen Dang Binh

**
* Concrete class for formatting large and small numbers, allowing a
variety
* of exponential/scientific notation
* @see java.util.Format
* @see java.text.NumberFormat
* @version 1.0 25 Jan 1998
* @author Elliotte Rusty Harold
*/
public class ExponentialFormat extends NumberFormat {
// might make this only a number format
DecimalFormatSymbols symbols;
DecimalFormat parser;
public ExponentialFormat() {
this(new DecimalFormat());
}
/**
* Create an ExponentialFormat from the given format and the symbols
* for the default locale.
*
* @param format The decimal format that parses the parts of the
exponential.
*/
public ExponentialFormat(DecimalFormat format) {
this.parser = format;
this.symbols = format.getDecimalFormatSymbols();
this.parser.setGroupingUsed(false);
}
public StringBuffer format(double number, StringBuffer toAppendTo,
FieldPosition pos) {
if (Double.isNaN(number)) {
toAppendTo.append(symbols.getNaN());
}
else if (number < 0) {
toAppendTo.append(symbols.getMinusSign());
number = -number;
}
// Now we just have to format a nonnegative number.
if (Double.isInfinite(number)) {
toAppendTo.append(symbols.getInfinity());
}
else {
int maxFractionDigits = this.getMaximumFractionDigits();
if (maxFractionDigits