Memory Leak: Do I need to explicitly free memory reference for collection?

Question

Hi,
My web application uses JRockit JDK 1.4.2, Java Servlet, JSP &Struts. It is a clustered environment using WL 8.1 sp 4. I am investigating whether there are any memory leaks in the application & what are best practices to avoid leaks.
A specific scenario is as follows:
For an incoming request, the struts action class creates object �O� (of class A) and set �O� as a request attribute. This request attribute is used to display values on the JSP.
Now, class A has a heavily nested structure: Class A has object of class B, where B has a HashSet of objects of type C and where C has an object of type D and E.
Though I set this object �O� in request scope, do I need to explicitly nullify any of the references within object �O�? Can �not doing this� result in a memory leak?
Thanks in advance,
sjaiprakash

Answer 1

jEnv->ReleaseStringUTFChars((jstring) jStr, str);free(str); //Is this line valid or outright wrong?Outright wrong.
Another question is if ReleaseStringUTFChars actually frees str then will it set str to NULL?No, that's impossible by the semantics of C and C++.
I guess not as we are not sending this pointer by reference.Exactly, so what you described is impossible. No need to ask really.
My last question is if str is NULL then calling ReleaseStringUTFChars over it can cause any problem?How could it be null? If it comes from GetStringUTFChars that's impossible, and if it doesn't you don't have any business calling ReleaseStringUTFChars() on it, whatever its value.