>I meant filters defined in web.xml, not scriptlets. It's /possible/ that >your <bean:> tags are using a whole lot of memory, but probably not >(you'd have to be creating randomly-named session attributes over and >over, and never freeing them... I'm guessing you're not doing that).
No, I'm not doing that. They are only <bean:mesasge> tags displaying some text... There are no filters or any special contents in my web.xml. >Can you expand the "+" next to Arrays.copyOfRange to see what the rest >of the stack trace is? I'm sure that a lot of things call >Arrays.copyOfRange, so it's hard to determine what the problem is. Post >another screenshot if you can. Sure, here it is (profiler3_expanded.JPG): http://www.inf.u-szeged.hu/~michnay/profiler/ As you can see, now there are other methods as well allocating char[] objects. It's pretty confusing and very hard to track how exactly my pages are processed by the server... at least, it is for me... :) >Your code looks just fine, although I might suggest factoring-out the >code to mess with JNDI, the DataSource, etc. and just write a method >that returns a Connection (or throws an exception). You are also closing >your resources out of order (stmt first, then conn, then rst). Since >you're closing those resources in your finally block, why bother closing >them in the method body? It will be a cleaner method without this extra >stuff in there, but functionally equivalent. I'll try to factor out the JNDI parts. Should I factor out the creation of statement and result objects as well, or only the connection should be factored out? Should I create another method to free up the resources? I'm not sure what's the best way of doing this. Do you have a sample code to take a look at? >In terms of design, I would write that method to return a List of >application-specific objects instead of maintaining two separate >(untyped) lists that just happen to be related. It is a much more >understandable design and yields much more readable code. It will also >simplify your JSP loop, etc. What do you mean by "List of application-specific objects"? Is it a multi-dimensional ArrayList object? I'm very interested in creating well-readable and well-understandable code, so some samples would be appreciated :) (sorry, I'm not very experienced in Java) >Do you see any place where objects could not be freed-up? Where? I'll show you. Please take a look at profiler4.JPG found at the same URL. The big black curly bracket shows how the memory is eaten up by simle page reloads. The profiler's GC button can be found at the upper-left corner indicated by the green arrow. By pressing GC, a small amount of memory is freed up, which can be seen in the yellow ellipse. It's a little slope indicating that a very little amount of memory could be freed up, no matter how many times I press the GC button. What about the rest? That's pretty confusing and sometimes a bit annoying, because I don't see where my code wastes ~25 Mbytes of memory... >Ouch! If you reload many times, does a JVM-initiated GC fire off? You >should be able to look at the GC graph to see if the JVM is at least >attempting to to a GC. It's possible to limit your JVM so much that even >simple things cause OOMs, especially /during/ GC runs. No, it's me firing off a GC by pressing the GC button of the profiler. There are no GC calls in my code... >You mentioned you were using Tomcat as well. I'm assuming that since >you're using Java 1.6 (Sun?), you're also using Tomcat 5.x or 6.x? Oh, yes, sorry, I'm using Tomcat 5.5 (bundled with NetBeans 5.5.17), MySQL server 5.0.37, under Win XP SP2. >No problem. We'll figure it out... but it might take a while. I remember >when I first started profiling my apps. I started freaking out because I >had no idea so many objects existed. At first I thought everything was >leaking memory, and it turns out that everything was working just fine. >The GC can play lots of tricks on you if you don't fully understand what >you're seeing. Yes, you're absolutely right, that's exactly what I think. I was about to accept that I'm just simply unable to comprehend what happen behind the scenes, but now - thanks to your helpfulness and willingness to help - things are getting clearer... You just simply don't see how much you help. Apart from the fact that my code is whether wastes or doesn't waste ~25 Mbytes of memory by virtually "doing nothing", it's very calming to see that other factors not directly related to my code can affect memory load. I appreciate every bits of help. Regards, BM ____________________________________________________________________________________ Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games. http://sims.yahoo.com/
