I read somewhere that Java Virtual Machine (JVM) is not Von-neumann architecture. Can someone please clarify why and/or how?
The JVM can be considered to be Harvard architecture rather than Von Neumann architecture, on the grounds that it separates code from data; they are treated as distinct kinds of things which are accessed via separate means.
However, this is not a particularly useful statement, because in an object-oriented VM like the JVM there is not a single untyped address space, or two of them, but rather many distinct kinds (classes) which cannot be addressed uniformly (outside of reflection operations, which are more or less bypassing the rules of the VM).