/**
 * Look up the best-matching handler method for the current request.
 * If multiple matches are found, the best match is selected.
 * @param lookupPath mapping lookup path within the current servlet mapping
 * @param request the current request
 * @return the best-matching handler method, or {@code null} if no match
 * @see #handleMatch(Object, String, HttpServletRequest)
 * @see #handleNoMatch(Set, String, HttpServletRequest)
 */
protected HandlerMethod lookupHandlerMethod(String lookupPath, HttpServletRequest request) throws Exception {
  List<Match> matches = new ArrayList<Match>();
  List<T> directPathMatches = this.urlMap.get(lookupPath);
  if (directPathMatches != null) {
    addMatchingMappings(directPathMatches, matches, request);
  }
  if (matches.isEmpty()) {
    // No choice but to go through all mappings...
    addMatchingMappings(this.handlerMethods.keySet(), matches, request);
  }

  if (!matches.isEmpty()) {
    // ...
    return bestMatch.handlerMethod;
  }
  else {
    return handleNoMatch(handlerMethods.keySet(), lookupPath, request);
  }
}

private void addMatchingMappings(Collection<T> mappings, List<Match> matches, HttpServletRequest request) {
  for (T mapping : mappings) {
    T match = getMatchingMapping(mapping, request);
    if (match != null) {
      matches.add(new Match(match, this.handlerMethods.get(mapping)));
    }
  }
}