JAVA IO流

纯文本字符流比字节流效率高.

1.这个理解的特别好：http://t.zoukankan.com/liaozuheng-p-13046873.html

2.节点流与处理流的介绍：https://blog.csdn.net/wcg920212/article/details/122352570

3.将流创建定义在try()中，不用finaly关闭流，反编译可以看效果，会自动close,代码如下：

public class Test{
    public static void main(String[] args) {
        try( InputStreamReader inputStreamReader = new InputStreamReader(System.in);
             OutputStreamWriter outputStreamWriter = new OutputStreamWriter(System.out);
             BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter);
             BufferedReader bufferedReader = new BufferedReader(inputStreamReader);) {
            String str = "";
            while (!str.equals("exit")) {
                str = bufferedReader.readLine();
                bufferedWriter.write(str);
                bufferedWriter.flush();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

4. commons apache的文件工具类