This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Spring you write POJOs and not tie any of your code to Spring, so if you decide later to use something else, then you don't have to re-write your code. I would be worried about Oracle's ADF being too tightly coupled into your code, where you would have to do a lot of work if you ever decide to use something else.
But I don't know how ADF works to be positive what I said above is even true about it.