how to decipher output?

[alexbootman]

What is this supposed to mean:
Private suspects in class com.vmware.vmtx.activities.VmtxActivityCallbackTest:
[Object[][] onFailureTestCases()]
How can I detect unused classes? How does DCD work with spring?
Sorry, but at the moment it looks useless.

[evernat]

Private suspects in class com.vmware.vmtx.activities.VmtxActivityCallbackTest:
[Object[][] onFailureTestCases()]

It means that the onFailureTestCases method is certainly not used in the class com.vmware.vmtx.activities.VmtxActivityCallbackTest. Said otherwise it is not called anywhere in your code.
So the onFailureTestCases method can certainly be removed.

DCD works with code using Spring like with any java code, but note that DCD does not know when reflection is used. In fact, Spring does not make a difference for DCD.