code: public void load(String config)
          throws IOException
      {
          _config=config;
          if(log.isDebugEnabled())log.debug("Load "+this+" from "+config);
          Properties properties = new Properties();
          Resource resource=Resource.newResource(config);
          properties.load(resource.getInputStream());
  
          Iterator iter = properties.entrySet().iterator();
          while(iter.hasNext())
          {
              Map.Entry entry = (Map.Entry)iter.next();
  
              String username=entry.getKey().toString().trim();
              String credentials=entry.getValue().toString().trim();
              String roles=null;
              int c=credentials.indexOf(',');
              if (c>0)
              {
                  roles=credentials.substring(c+1).trim();
                  credentials=credentials.substring(0,c).trim();
              }
  
              if (username!=null && username.length()>0 &&
                  credentials!=null && credentials.length()>0)
              {
                  put(username,credentials);
                  if(roles!=null && roles.length()>0)
                  {
                      StringTokenizer tok = new StringTokenizer(roles,", ");
                      while (tok.hasMoreTokens())
                          addUserToRole(username,tok.nextToken());
                  }
              }
          }
      }
docs: Load realm users from properties file.
  The property file maps usernames to password specs followed by
  an optional comma separated list of role names.
  
  @param config Filename or url of user properties file.
  @exception IOException