Regexp problem when extracting filename from path

Question

I'm trying to extract filename and full path from string: \dir1\dir2\file.name
import java.util.regex.*;
public class Main {  
    private static final String REGEX = "(\\S*\\)*(\\S*)";
    private static final String INPUT = "\\dir1\\dir2\\file.name";
    public Main() {    }   
    public static void main(String[] args) {
       Pattern p = Pattern.compile(REGEX);
       Matcher m = p.matcher(INPUT); // get a matcher object
       int count = 0;      
       if(m.find()) {
           count++;          
           System.out.println("group1: "+m.group(1));
           System.out.println("group2: "+m.group(2));                     
}I expect group1 to be \dir1\dir2\ and group2 file.name
when I run program exception is thrown:
Exception in thread "main" java.util.regex.PatternSyntaxException: Unclosed group near index 12
(\S*\)*(\S*)
^
at java.util.regex.Pattern.error(Pattern.java:1650)
at java.util.regex.Pattern.accept(Pattern.java:1508)
at java.util.regex.Pattern.group0(Pattern.java:2460)
at java.util.regex.Pattern.sequence(Pattern.java:1715)
at java.util.regex.Pattern.expr(Pattern.java:1687)
at java.util.regex.Pattern.compile(Pattern.java:1397)
at java.util.regex.Pattern.<init>(Pattern.java:1124)
at java.util.regex.Pattern.compile(Pattern.java:817)
at javaapplication2.Main.main(Main.java:15)

Answer 1

'jverd' is right but if you are just trying to split the INPUT into a path + filename then why not just look for the last '\'. i.e.
int lastSlash = INPUT.lastIndexOf('\\');
String group1 = INPUT.substring(0, lastSlash);
String group2 = INPUT.substring(lastSlash+1);
As it stands, your example will not give you group 1 as \dir1\dir2. For that you would need something like
"((?:\\[^\\])*)(\\.*)"
to make sure you capure all the path in group 1.