java7 NIO2(8)The Asynchronous Channel API 异步通道API
异步channelAPI主要引入三个异步类:AsynchronousFileChannel,AsynchronousSocketChannel,andAsynchronousServerSocketChannel.AsynchronousFileChannel跟FileChannel区别:不保存全局的position和offset,可以制定访问位置,也支持并发访问文件不同。Asynchronous