@Override
    public List<String> selectList(String text) {
        List<String> strings = new ArrayList<String>();
        List<RegexResult> results = selectGroupList(text);
        for (RegexResult result : results) {
            strings.add(result.get(group));
        }
        return strings;
    }
Create a RegexSelector. When there is no capture group, the value is set to 0 else set to 1.
@param regexStr the regular expression.
webmagic-core/src/main/java/us/codecraft/webmagic/selector/RegexSelector.java