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.
Using JNDI will only work for Java clients, as you point out. But is also uses some non-standard ports which you may not want to open up to the world. Web Services require only port 80 (and/or 443), which are usually open already.