Java 8 in Action

Java 8 in Action is the Simplified Chinese edition of Manning's Java 8 in Action, translated by Lu Minggang and Lao Jia and published by Posts & Telecom Press in its Turing Programming Series · Java. Centered on Java 8, a landmark release, the book systematically explains its core new features—lambda expressions, method references, the Stream API, default methods, Optional, CompletableFuture, and the new date-time API—and illustrates them throughout with Java code examples drawn from real business scenarios, showing how a functional style can produce programs that are more concise, easier to maintain, and able to exploit multiple cores automatically. The book has 16 chapters in four parts. Part 1, Fundamentals, begins with why Java is still evolving and introduces behavior parameterization and passing code, then lambda expressions. Part 2, Functional-Style Data Processing, covers the introduction and use of streams, collecting data with streams, and parallel data processing and performance. Part 3, Efficient Java 8 Programming, addresses refactoring, testing, and debugging; default methods; replacing null with Optional; composable asynchronous programming with CompletableFuture; and the new date and time API. Part 4, Beyond Java 8, discusses functional thinking, functional programming techniques, and blending object-oriented and functional programming (comparing Java 8 with Scala), and looks ahead to Java's future. Four appendices cover updates to the language and class libraries, performing multiple operations concurrently on the same stream, and lambdas and JVM bytecode. Each chapter ends with a summary and a quiz for checking understanding along the way, making the book a standard reference for Java developers seeking a systematic grasp of Java 8's new features.