6.NIO基础补习

NIO
java IO 的核心是流Stream。
输入流和输出流
字节流和字符流

读数据的逻辑：

1. open a stream
2. while more information
3. read information
4. close the stream

写数据的逻辑：

1. open a stream
2. while more information
3. write information
4. close the stream

节点流和过滤流

Decorator设计模式

InputStream
FilterInputStream
BufferedInputStream

A container for data of a specific primitive type.
A buffer is a linear, finite sequence of elements of a specific primitive type. Aside from its content, the essential properties of a buffer are its capacity, limit, and position

A buffer's limit is the index of the first element that should not be read or written.