code: public String calculateWebAlias(Dictionary<String, String> dictionary)
      {
          String alias = dictionary.get(BaseWebappServlet.ALIAS);
          if (alias == null)
              alias = dictionary.get(BaseWebappServlet.ALIAS.substring(BaseWebappServlet.PROPERTY_PREFIX.length()));
          if (alias == null)
              alias = this.getAlias();
          if (alias == null)
              alias = context.getProperty(BaseWebappServlet.ALIAS);
          if (alias == null)
              alias = context.getProperty(BaseWebappServlet.ALIAS.substring(BaseWebappServlet.PROPERTY_PREFIX.length()));
          if (alias == null)
              alias = DEFAULT_WEB_ALIAS;
          return alias;
      }
docs: Figure out the correct web alias.
  @param dictionary
  @return