I'm trying to parse some text, but for some strange reason, Java regex doesn't work. For example, I've tried:
Pattern p = Pattern.compile("[A-Z][0-9]*,[0-9]*");
Matcher m = p.matcher("H3,4");
and it simply gives No match found exception, when I try to get the numbers m.group(1) and m.group(2). Am I missing something about how Java regex works?
Yes.
matches() or find() on the matcher first.Example:
Pattern p = Pattern.compile("[A-Z](\\d*),(\\d*)");
matcher m = p.matcher("H3,4");
if (m.matches()) {
// use m.group(1), m.group(2) here
}
You also need the parenthesis to specify what is part of each group. I changed the leading part to be anything that's not a digit, 0 or more times. What's in each group is 1 or more digits. So, not * but + instead.
Pattern p = Pattern.compile("[^0-9]*([0-9]+),([0-9]+)");
Matcher m = p.matcher("H3,4");
if (m.matches())
{
String g1 = m.group(1);
String g2 = m.group(2);
}
