About this tutorial The new input/output (NIO) library was introduced with JDK 1.4. Picking up whereoriginal I/O leaves off, NIO provides high-speed, block-oriented I/O in standard Javacode. By defining classes to hold data, and by processing that data in blocks, NIOtakes advantage of low-level optimizations in a way that the original I/O package couldnot, without using native code. In this tutorial, we'll cover almost every aspect of the NIO library, from the high-levelconceptual stuff to under-the-hood programming detail. In addition to learning aboutcrucial I/O elements like buffers and channels, you'll have the opportunity to see howstandard I/O works in the updated library. You'll also learn about things you can only dowith NIO, such as asynchronous I/O and direct buffers. Throughout the tutorial, we'll work with code samples that illustrate different aspects ofthe NIO library. Almost every code sample is part of an extended Java program, whichyou'll find in Resources on page 38 . As you are working through the exercises, you're encouraged to download, compile, and run these programs on your own system. Thecode will also come in handy when you're done with the tutorial, providing a startingpoint for your NIO programming efforts. This tutorial is intended for any programmer who wants to learn more about the JDK1.4 NIO library. To get the most from the discussion you should understand basic Javaprogramming concepts such as classes, inheritance, and using packages. Somefamiliarity with the original I/O library (from the java.io.* package) will also be helpful.