Numbers - Java - page 188

Discussion

Nothing in the standard API formats Roman numerals. But the java.text.Format class is
designed to be subclassed for precisely such unanticipated purposes, so I have done just that
and developed a class to format numbers as Roman numerals. Here is a better and complete
example program of using it to format the current year. I can pass a number of arguments on
the command line, including a “ - ” where I want the year to appear (note that these arguments
are normally not quoted; the “ - ” must be an argument all by itself, just to keep the program
simple). I use it as follows:

$ java numbers.RomanYear Copyright (c) - Ian Darwin
Copyright (c) MMXIV Ian Darwin
$

The code for the RomanYear program is simple, yet it correctly puts spaces around the argu-
ments:

public public class class RomanYear RomanYear {

public public static static void void main ( String [] argv ) {

RomanNumberFormat rf = new new RomanNumberFormat ();

Calendar cal = Calendar . getInstance ();
int int year = cal . get ( Calendar . YEAR );

// If no arguments, just print the year.
iif ( argv . length == 0 ) {
System . out . println ( rf . format ( year ));
return

return ;

}

// Else a micro-formatter: replace "-" arg with year, else print.
for

for ( int int i = 0 ; i < argv . length ; i ++) {

iif ( argv [ i ]. equals ( "-" ))
System . out . print ( rf . format ( year ));

else

System . out . print ( argv [ i ]); // e.g., "Copyright"

System . out . print ( ' ' );

}
System . out . println ();

}

}