Functional Programming in Java, 2nd Edition

Chapter 11Refactoring to Functional Style

In the past, Java programmers could only write object-oriented code using the imperative style of programming. Today they can write object-oriented code using either the imperative style or the functional style. It’s nice to have such choices when writing code. Functional style code may not be ideal all the time, for example, to deal with side-effects or exceptions as we saw in the previous chapter. But it does win over the imperative style by reducing accidental complexity and making code easier to read and understand.

When we sit down to write new code, we can reach out to our functional programming skills. But many enterprise applications aren’t greenfield. We’re often thrown into a codebase that ...