Functional Programming in Java

Performance Concerns

Java has come a long way and is used in a vast number of enterprise applications where performance is critical. It’s reasonable to ask if the new features will affect performance. The answer is yes, but mostly for the better!

Before we dig into that, let’s recall Donald Knuth’s wise words: “We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil.”^[19] With that in mind, we should boldly try out the new style where it makes sense. If the performance we get is adequate for the needs of the application, we can move on. Otherwise, we have to critically evaluate the design and profile the code to figure out the real bottlenecks.

The Java 8 specification provides a ...