code: @Override
  	public void doTag() throws JspException, IOException {
  		try {
  			JspContext  context     = getJspContext();
  			JspFragment fragment    = getJspBody();
              PageContext pageContext = (PageContext) context;
  			
              // invoke before event
  			beforeDoTag(context, fragment);
  
              // 내장객체 추가
              innerInstance.put("param",   TagUtils.getRequestParameterMap(pageContext));
              innerInstance.put("request", TagUtils.getRequestAttributeMap(pageContext));
              innerInstance.put("session", TagUtils.getSessionAttributeMap(pageContext));
              innerInstance.put("cookie",  TagUtils.getCookieMap(pageContext));
              innerInstance.putAll(dynamicAttrMap);
  
              Object[]  params      = new Object[] { this, innerInstance };
              String    mustacheKey = getClass().getCanonicalName();
              AXUConfig config      = ConfigReader.getConfig();
  
              if (this instanceof CustomTag) {
                  CustomTag customTag = (CustomTag) this;
                  mustacheKey = mustacheKey + "#" + customTag.getCustomid();
              }
  
              mustacheHtml = mustacheCacheMap.get(mustacheKey);
              if (mustacheHtml == null) {
  				if (tagBody == null) {
  					throw new RuntimeException("tag body is empty. please check your aux4j.xml");
  				}
  
                  mustacheHtml = mustacheFactory.compile(new StringReader(tagBody), mustacheKey);
  
                  if (!StringUtils.equalsIgnoreCase("DEV", config.getMode())) {
                      mustacheCacheMap.put(mustacheKey, mustacheHtml);
                  }
              }
              mustacheHtml.execute(context.getOut(), params);
  
              // invoke after event
  			afterDoTag(context, fragment);
  			
  		} catch (Exception e) {
  			logger.error(String.format("doTag is fail.\ntagBody: %s\nmustacheHtml: %s", tagBody, (mustacheHtml == null ? "null" : mustacheHtml.toString())), e);
  		}
  
  	}
docs: override doTag method