packageJava10;importjava.io.*;importjava.nio.charset.StandardCharsets;//字节流:输入流(FileInputStream):读,输出流(FileOutputStream):写publicclassInputOutputStream{publicstaticvoidmain(String[] args)throwsException{//FileInputStream:读文件InputStream is =null;try{
is =newFileInputStream("D:/java/test1/src/a.txt");byte[] b = is.readAllBytes();String s =newString(b);System.out.println(s);}catch(IOException e){
e.printStackTrace();}finally{try{if(is !=null){
is.close();}}catch(IOException e){
e.printStackTrace();}}//FileOutputStream:写文件OutputStream o =newFileOutputStream("D:/java/test1/src/a.txt");byte[] b1 ="hello,晓晓".getBytes(StandardCharsets.UTF_8);
o.write(b1);
o.close();}}