private KeyDescription parseKey()

in odps-sdk/odps-sdk-mapred/src/main/java/com/aliyun/odps/mapred/lib/KeyFieldHelper.java [203:293]
85 lines of code
21 McCabe index (conditional complexity)

  private KeyDescription parseKey(String arg, StringTokenizer args) {
    //we allow for -k<arg> and -k <arg>
    String keyArgs = null;
    if (arg.length() == 2) {
      if (args.hasMoreTokens()) {
        keyArgs = args.nextToken();
      }
    } else {
      keyArgs = arg.substring(2);
    }
    if (keyArgs == null || keyArgs.length() == 0) {
      return null;
    }
    StringTokenizer st = new StringTokenizer(keyArgs, "nr.,", true);

    KeyDescription key = new KeyDescription();

    String token;
    //the key is of the form 1[.3][nr][,1.5][nr]
    if (st.hasMoreTokens()) {
      token = st.nextToken();
      //the first token must be a number
      key.beginFieldIdx = Integer.parseInt(token);
    }
    if (st.hasMoreTokens()) {
      token = st.nextToken();
      if (token.equals(".")) {
        token = st.nextToken();
        key.beginChar = Integer.parseInt(token);
        if (st.hasMoreTokens()) {
          token = st.nextToken();
        } else {
          return key;
        }
      }
      do {
        if (token.equals("n")) {
          key.numeric = true;
        } else if (token.equals("r")) {
          key.reverse = true;
        } else {
          break;
        }
        if (st.hasMoreTokens()) {
          token = st.nextToken();
        } else {
          return key;
        }
      } while (true);
      if (token.equals(",")) {
        token = st.nextToken();
        //the first token must be a number
        key.endFieldIdx = Integer.parseInt(token);
        if (st.hasMoreTokens()) {
          token = st.nextToken();
          if (token.equals(".")) {
            token = st.nextToken();
            key.endChar = Integer.parseInt(token);
            if (st.hasMoreTokens()) {
              token = st.nextToken();
            } else {
              return key;
            }
          }
          do {
            if (token.equals("n")) {
              key.numeric = true;
            } else if (token.equals("r")) {
              key.reverse = true;
            } else {
              throw new IllegalArgumentException("Invalid -k argument. " +
                                                 "Must be of the form -k pos1,[pos2], where pos is of the form "
                                                 +
                                                 "f[.c]nr");
            }
            if (st.hasMoreTokens()) {
              token = st.nextToken();
            } else {
              break;
            }
          } while (true);
        }
        return key;
      }
      throw new IllegalArgumentException("Invalid -k argument. " +
                                         "Must be of the form -k pos1,[pos2], where pos is of the form "
                                         +
                                         "f[.c]nr");
    }
    return key;
  }