Regular Expressions and GWT

Solution 1:

The same code using RegExp could be:

// Compile and use regular expression
RegExp regExp = RegExp.compile(patternStr);
MatchResult matcher = regExp.exec(inputStr);
boolean matchFound = matcher != null; // equivalent to regExp.test(inputStr); 

if (matchFound) {
    // Get all groups for this match
    for (int i = 0; i < matcher.getGroupCount(); i++) {
        String groupStr = matcher.getGroup(i);
        System.out.println(groupStr);
    }
}

Solution 2:

GWT 2.1 now has a RegExp class that might solve your problem:

Solution 3:

This answer covers ALL pattern matches, not only one, as in other answers here:

Function:

private ArrayList<String> getMatches(String input, String pattern) {
    ArrayList<String> matches = new ArrayList<String>();
    RegExp regExp = RegExp.compile(pattern, "g");
    for (MatchResult matcher = regExp.exec(input); matcher != null; matcher = regExp.exec(input)) {
       matches.add(matcher.getGroup(0));
    }
    return matches;
}

...and sample use:

ArrayList<String> matches = getMatches(someInputStr, "\\$\\{[A-Za-z_0-9]+\\}");
for (int i = 0; i < matches.size(); i++) {
    String match = matches.get(i);

}

Solution 4:

If you want a pure GWT solution, I'm not sure it can be done. But if you're willing to use JSNI, you can use JavaScript's RegExp object to get the matched groups and all. You'll need to learn JSNI for GWT and JavaScript RegExp object.