code: @Override
  	public int doStartTag() throws JspException {
  
  		HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
  
  		if (null == pageContext.getServletContext().getAttribute(getResourceHandlerAttributeName()))
  			throw new IllegalStateException(
  					"ResourceBundlesHandler not present in servlet context. Initialization of Jawr either failed or never occurred.");
  
  		ResourceBundlesHandler rsHandler = (ResourceBundlesHandler) pageContext.getServletContext()
  				.getAttribute(getResourceHandlerAttributeName());
  		JawrConfig jawrConfig = rsHandler.getConfig();
  
  		if (RendererRequestUtils.refreshConfigIfNeeded(request, jawrConfig)) {
  			rsHandler = (ResourceBundlesHandler) pageContext.getServletContext()
  					.getAttribute(getResourceHandlerAttributeName());
  			jawrConfig = rsHandler.getConfig();
  		}
  
  		Boolean useRandomFlag = null;
  		if (StringUtils.isNotEmpty(useRandomParam)) {
  			useRandomFlag = Boolean.valueOf(useRandomParam);
  		}
  		// Renderer istance which takes care of generating the response
  		BundleRenderer renderer = createRenderer(rsHandler, useRandomFlag);
  
  		// set the debug override
  		RendererRequestUtils.setRequestDebuggable(request, jawrConfig);
  
  		try {
  			BundleRendererContext ctx = RendererRequestUtils.getBundleRendererContext(request, renderer);
  			renderer.renderBundleLinks(src, ctx, pageContext.getOut());
  
  		} catch (IOException ex) {
  			throw new JspException("Unexpected IOException when writing script tags for path " + src, ex);
  		} finally {
  			// Reset the Thread local for the Jawr context
  			ThreadLocalJawrContext.reset();
  		}
  
  		return SKIP_BODY;
  	}
docs: /*
  (non-Javadoc)
  
  @see javax.servlet.jsp.tagext.TagSupport#doStartTag()