java的FileOutputStream,FileInputStream

package javaTest01;

import java.io.*;

public class StreamTest02 {

    public static void main(String[] args) throws IOException {
        File file2=new File("config/streamTest02");
        file2.mkdirs();
        File file=new File("config/streamTest02/test.txt");

        //**************写文件

        // 构建FileOutputStream对象,文件不存在会自动新建(但路径必须存在)
        FileOutputStream fos=new FileOutputStream(file);
        // 构建OutputStreamWriter对象,参数可以指定编码,默认为操作系统默认编码,windows上是gbk
        OutputStreamWriter writer=new OutputStreamWriter(fos,"UTF-8");

        // 写入到缓冲区
        writer.append("烟花三月下扬州");
        writer.append("\r\n");
        writer.append("where there is a will there is a way");

        // 关闭写入流,同时会把缓冲区内容写入文件
        writer.close();
        fos.close();


        //**************读文件

        FileInputStream fis=new FileInputStream(file);
        InputStreamReader reader=new InputStreamReader(fis,"UTF-8");
        StringBuffer sb=new StringBuffer();
        while (reader.ready()){
            // 转成char加到StringBuffer对象中
            sb.append((char) reader.read());
        }
        System.out.println("sb: " + sb.toString());
        reader.close();
        fis.close();


    }
}