Converting from Java 7 to 6, Matcher.group

Question

I'm converting a Java 7 application to a Java 6 application. I'm stuck on the matcher.group property, since I don't really understand what it does.

I have the following code:

public static final String PropertyRegexPrefixGroup = "prefix";
public static final String PropertyRegexPostfixGroup = "postFix";

public static ParsedProperty parse(String property) {
    Matcher matcher = PropertyRegex.matcher(property);
    boolean isMatch = matcher.matches();
    if (!isMatch)
        return new ParsedProperty(null, property, false);

    String prefix = matcher.group(PropertyParser.PropertyRegexPrefixGroup);
    String postfix = matcher.group(PropertyParser.PropertyRegexPostfixGroup);
    return new ParsedProperty(prefix, postfix, true);
}

I have to rewrite the String prefix and String postfix property declarations. How can I achieve this?

Answer 1

In Java 6, you can't have named groups, so you need to reference the groups by index.

Given this pattern:

Pattern pattern = Pattern.compile("(foo).*(bar)")

and this code:

Matcher matcher = pattern.matcher("foo....something...else...bar");
matcher.find();

matcher.group(0) matches the entire String, matcher.group(1) returns "foo" and matcher.group(2) returns "bar"