I just don't get this JProfiler

I have been

trying to figure out how to use JProfiler.The manual is too big, too confusing and I don't know where to start. I just want to do a simple thing, i have written a very basic java program and i want to check how efficient it is.

I just want to know the following things in my program :

how much heap/stack memory each variable is taking

How much time its taking to execute a loop.

How much time it takes to execute a method.

How much heap memory my array is taking.

How much time it is taking to read/write to a file is taking.

Has the explicit casting that i use in my program making any difference or not .

I could not find any tutorials for Jprofiler.
Someone please guide me in the right direction.

I haven't used jprofiler, but visualvm comes with the jdk and does a lot of what you are asking. It is relatively straightforward too.

You could also try appdynamics lite which is free: http://litedocs.appdynamics.com/display/ADLite/Get+started+With+AppDynamics+Lite