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.
The online book Java Platform Performance has some basic rules regarding IO performance, along with ideas on how to measure and compare throughput. The upper bound on throughput is going to be your network, and there's not much tweaking Java code can do a bout that.