Debug spring mvc view rendering time - spring-mvc

Question

I am currently using Spring MVC 3.x,
and using the freemarker view resolver.
Recently i have been wondering about the execution time that it takes for a view to translate into html before getting sent back as a response. I would like to do tunings if things are slow in this area, which is why i need some numbers.
In plain freemarker mode, i can actually do the simple System.currentTimeMillis() between these to find out the execution time :
long start = System.currentTimeMillis();
// this could be slow or fast depending on the caching used
Template temp = cfg.getTemplate(ftlName);
...
temp.process(model, myWriter); // depends on the writer
System.out.printf("done in %s ms", System.currentTimeMillis() - start);
But how do i do this when with spring mvc's freemaker view rendering ?

Answer 1

You might consider extending org.springframework.web.servlet.view.freemarker.FreeMarkerView and configuring FreeMarkerViewResolver with your custom logging view implementation.
Logging view implementation could look like this:
public class LoggingFreeMarkerView extends FreeMarkerView {
private static final transient Log log = LogFactory.getLog(LoggingFreeMarkerView.class);
#Override
protected void doRender(Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
long start = System.currentTimeMillis();
super.doRender(model, request, response);
log.debug("Freemarker rendered " + request.getRequestURI() + " in " + (System.currentTimeMillis() - start) + " ms");
}
}
And wire the view resolver with new class:
<bean id="viewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver" autowire="no">
<property name="viewClass" value="com.example.LoggingFreeMarkerView" />
<property name="cache" value="false" /> <!-- cache disabled for performance monitoring -->
<property name="prefix" value="" />
<property name="suffix" value=".ftl" />
<property name="contentType" value="text/html;charset=utf-8" />
<property name="exposeRequestAttributes" value="true" />
<property name="requestContextAttribute" value="base" />
</bean>

Answer 2

You are going to calculate just on server side merging template with data,Main problem is when freemarker executing on page ,As you know freemarker built on top of jsp page so you should bring code to jsp side to calculate execution time,
As my experience according to data size load time in freemarker is different.
if else condition also is too slow compare to jstl!
I can recommend thymeleaf for spring that allowing templates to be working prototypes on not xml style .