Kyle Kyle - 1 year ago 106
Java Question

Possible Memory leak in Number of Loaded classes in Java Application

I recently began profiling an osgi java application that I am writing using VisualVM. One thing I have noticed is that when the application starts sending data to a client (over JMS), the number of loaded classes starts increasing at a steady rate. The Heap size and the PermGen size remains constant, however. The number of classes never falls, even after it stops sending data. Is this a memory leak? I think it is, because the loaded classes have to be stored somewhere, however the heap and permgen never increase even after I run the application for several hours.

For the screenshot of my profiling application go here

Answer Source

Are you dynamically creating new classes on the fly somehow?

Thanks for your help. I figured out what the problem is. In one of my classes, I was using Jaxb to create an XML string. In doing this, JAXB ueses reflection to create a new class.

JAXBContext context = JAXBContext.newInstance(this.getClass());

So although the JAXBContext wasn't saying around in the heap, the classes had been loaded.

I have run my program again, and I see a normal plateau as I would expect.

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