docs: public static String getRelPath(String siblings, String resourceId)
  	{
  
  		String relResourceId = null;
  		if (resourceId != null && resourceId.length() != 0)
  		{
  			char cs = resourceId.charAt(0);
  			if (!(cs == '\\' || cs == '/'))
  			{
  				//相对路径
  				int i = siblings.length() - 1;
  				boolean find = false;
  				for (; i > 0; i--)
  				{
  					char c = siblings.charAt(i);
  					if (c == '\\' || c == '/')
  					{
  						find = true;
  						break;
  					}
  				}
  				if (find)
  				{
  					String parent = siblings.substring(0, i + 1);
  
  					relResourceId = parent.concat(resourceId);
  				}
  				else
  				{
  					relResourceId = resourceId;
  				}
  
  			}
  			else
  			{
  				relResourceId = resourceId;
  			}
  			if (BeetlUtil.isOutsideOfRoot(relResourceId))
  			{
  				throw new RuntimeException("不能访问外部文件或者模板");
  			}
  			return relResourceId;
  		}
  		else
  		{
  			throw new RuntimeException("资源ID为空，参数错");
  		}
  
  	}