code: static String nameConvert(String name, boolean mapCamelCaseToUnderscore) {
      if (!mapCamelCaseToUnderscore)
        return name;
      StringBuilder sbd = new StringBuilder();
      char prevChar = name.charAt(0);
      sbd.append(Character.toLowerCase(prevChar));
      for (int i = 1, len = name.length(); i < len; i++) {
        char c = name.charAt(i);
        if (Character.isUpperCase(c)) {
          int next = i + 1;
          char nextChar = (next < len) ? name.charAt(next) : '\0';
          if (Character.isLowerCase(prevChar) || Character.isLowerCase(nextChar)) {
            sbd.append('_');
          }
          sbd.append(Character.toLowerCase(c));
        } else {
          sbd.append(c);
        }
        prevChar = c;
      }
      return sbd.toString();
    }
docs: 将当前的类名转换成数据库表名或者列名。
  例如：Blog -> blog， HTTPClient -> http_client, BlogAuthor -> blog_author
  
  @return 转换后的名字