Profiling software looks for bottlenecks in program execution. In addition to the profiling services provided by IDEs and standalone profilers, the framework provides its own internal support for profiling.
Profiling aspects
Struts2 profiling aspects involves the following :-
- ActionContextCleanUp
- FreemarkerPageFilter
- DispatcherFilter
- Dispatcher
- creation of DefaultActionProxy
- creation of DefaultActionInvocation
- creation of Action
- execution of DefaultActionProxy
- invocation of DefaultActionInvocation
- invocation of Interceptors
- invocation of Action
- invocation of PreResultListener
- invocation of Result
Using
To enable profiling, first make sure that the profiling interceptor is applied to your action, like:
Then enable profiling using one of the following methods:
Activate Through System property
This could be done in the container startup script eg. CATALINA_OPTS in catalina.sh (tomcat) or using "java -Dxwork.profile.activate=true -jar start.jar" (jetty)
Activate Through code
This could be done in a static block, in a Spring bean with lazy-init="false", in a Servlet with init-on-startup as some numeric value, in a Filter or Listener's init method etc.
Activate Through parameter
Changing the activation parameter name
Set the profilingKey attribute of the profiling interceptor to the desired name:
Filtering profile information
One could filter out the profile logging by having a System property as follows:
With this xwork.profile.mintime property, one could only log profile information when its execution time exceed those specified in xwork.profile.mintime system property. If no such property is specified, it will be assumed to be 0, hence all profile information will be logged.
Write profiling code
One could extend the profiling feature provided by Struts2 in their web application as well.
Using UtilTimerStack's push and pop
Using a UtilTimerStack's ProfileBlock template
Profiling Log files
Profiled result is logged using commons-logging under the logger named com.opensymphony.xwork2.util.profiling.UtilTimerStack. Depending on the underlying logging implementation, say if it is Log4j, one could direct the log to appear in a different file, being emailed to someone or have it stored in the db.