Java 8 in Action

While the term "lambda expression" may sound abstract and academic, Java 8 Lambdas can have a big impact on how you program every day. In simplest terms, a lambda expression is a function—a bit of code—that you can pass to another method as an argument. Thus, you can cope with changing requirements by using a behavior, represented by a lambda, as a parameter. Java 8's functional programming features, like lambdas and the new Stream API that enables a cleaner way to iterate through collections, can help you write concise, maintainable code that scales easily and performs well on multicore architectures.
Java 8 in Action is a clearly-written guide to Java 8 lambdas and functional programming in Java. It begins with a practical introduction to the structure and benefits of lambda expressions in real-world Java code. The book then introduces the Stream API and shows how it can make collections-related code radically easier to understand and maintain. Along the way, you'll discover new FP-oriented design patterns with Java 8 for code reuse, code readability, exception handling, data manipulation, and concurrency. For developers also exploring other functional languages on the JVM, the book concludes with a quick survey of useful functional features in Scala.