Java NIO 深入解析:提升程序执行效率

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"Java NIO (中文版) 是一本由Ron Hitchens撰写,裴小星翻译的书籍,详细介绍了Java 1.4版引入的非阻塞I/O(New Input/Output)特性。这本书旨在帮助Java开发者提升代码执行效率,解决实际工作中遇到的I/O问题,并探讨新I/O特性的潜在能力。书中不仅涵盖了NIO API的使用,还讨论了何时选择NIO或传统的1.3版I/O API。 NIO的核心概念包括缓冲区(Buffer)、通道(Channel)和选择器(Selector)。缓冲区提供了一种在进行I/O操作时存储数据的方法,减少了对CPU资源的依赖。创建和操作缓冲区的技巧,如复制缓冲区、字节缓冲区的使用,都是提升性能的关键。通道是数据传输的途径,支持Scatter/Gather传输方式,可用于文件、内存映射文件和套接字等不同类型的I/O操作。内存映射文件允许直接在内存中访问文件,提高了读写效率。套接字通道则处理网络通信,而管道(Pipe)用于线程间通信。 选择器是NIO中的多路复用机制,允许单个线程监控多个通道的状态,从而实现异步I/O。选择器的基础知识、选择键的使用以及选择器的缩放策略都是提高系统可伸缩性和响应速度的关键。 此外,书中还涉及了正则表达式,这是在处理文本数据时的强大工具,Java提供了正则表达式API,可以用于字符串的匹配和检索。最后,字符集章节讲解了字符编码的基本概念和Java中的字符集处理,这对于处理国际化和本地化数据至关重要。 这本书深入浅出地讲解了Java NIO的所有关键组件和使用场景,对于希望提升Java应用性能的开发者来说是一份宝贵的资源。"
2018-04-28 上传
Input/output (I/O) is not a sexy subject, but it’s an important part of non-trivial applications. This book introduces you to most of Java’s I/O capabilities as of Java 8 update 51. Chapter 1 presents a broad overview of I/O in terms of Java’s classic I/O, New I/O (NIO), and NIO.2 categories. You learn what each category offers in terms of its capabilities, and you also learn about concepts such as paths and Direct Memory Access. Chapters 2 through 5 cover classic I/O APIs. You learn about the File and RandomAccessFile classes along with streams (including object serialization and externalization) and writers/readers. Chapters 6 through 11 focus on NIO. You explore buffers, channels, selectors, regular expressions, charsets, and formatters. (Formatters were not introduced with the other NIO types in Java 1.4 because they depend on the variable arguments capability that was introduced in Java 5.) NIO is missing several features, which were subsequently provided by NIO.2. Chapters 12 through 14 cover NIO.2’s improved file system interface, asynchronous I/O, and the completion of socket channel functionality. Each chapter ends with assorted exercises that are designed to help you master its content. Along with long answers and true/false questions, you are often confronted with programming exercises. Appendix A provides the answers and solutions. Appendix B provides a tutorial on sockets and network interfaces. Although not directly related to classic I/O, NIO, and NIO.2, they leverage I/O capabilities and are mentioned elsewhere in this book.