Numberformater or substring or ????

[Frank Jacobsen]

If have a string that looks like this:

String test = "111122223333444";

I have to convert this string to:

String result = "1111-2222-3333-4444";

I now i can do this very easy, when i take a sbbstring 4 times like this:

String string1 = test.substring(0,4);
String string2 = test.substring(4,8);
String string3 = test.substring(8,12);
String string4 = test.substring(12);
result = string1 + "-" +  string2 + "-" + string3 + "-" + string4;

But is there a easyer or better way, maybe with NumberFormatter, im running java 1.3 ???

Frank Jacobsen

[Leo Deegan]

Hi there Frank,

I'm not sure what your parsing rules are exactly, but I'm guessing that you want a dash between every grouping of four digits for a number that is 16 digits long. A number that large can be handled by a java.math.BigDecimal. Here's my main method to test out a DecimalFormat approach (sorry, I did this in JDK 1.4.2, but try it out in 1.3 and see if it works):

public static void main(String[] args) {
    DecimalFormat f = new DecimalFormat("####,####,####,####");
    DecimalFormatSymbols symbols = new DecimalFormatSymbols();
    symbols.setGroupingSeparator('-');
    f.setDecimalFormatSymbols(symbols);
 
    BigDecimal n = new BigDecimal("1111222233334444");
    
    System.out.println(f.format(n));
}

[Jim Yingst]

One problem here is, what if the number begins with zeros? E.g. "0000111122223333" will be written as "1111-2222-3333", which probably isn't what you'd want. It's possible to write code to prepend 0's and -'s as necessary, but this will end up being more complex than the initial solution with substring.

One possible problem with the substring() approach - is it possible that the string might be less than 12 digits? If the input is "123456", is that an error? Or should that be rendered as "0000-0012-3456"? The latter will require some extra coding. Hopefully this is an erroneous input you don't have to deal with, but it might be worth considering.

[Frank Jacobsen]

Thanks

That helpt me a lot !




Frank