Use DecimalFormat to format numbers, and correspondingly you can use SimpleDateFormat to format time
import?java.text.DecimalFormat;
import?java.text. Format;
public?class?$?{
public?static?void?main(String[]?args)?{
int?num? =?1;
Format?f1?=?new?DecimalFormat("000");
System.out.println(f1.format(num));
Format?f2?=?new?DecimalFormat("00");
System.out.println(f2.format(num));
}
p>
}