021.10 IO流 打印流

内容：PrintStream:字节流    PrintWriter:字符流

PrintStream

public static void main(String[] args) throws IOException
{
    //创建对象
    PrintStream ps = new PrintStream("myfile\\print.txt");

    //写入整数
    ps.write(355); //文件里面是c，只是写入整数的最低字节，也就是最后8位二进制
    ps.print(355);  //文件里面是355，写什么就是什么,原理就是把数组转成了字符串

    ps.close();
}

PrintWriter

public static void main(String[] args) throws IOException
{
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    PrintWriter pw = new PrintWriter(System.out);
    String line = null;
    while((line = br.readLine()) != null){
        if("//over".equals(line)){
            break;
        }
        pw.println(line.toUpperCase());
        pw.flush();
    }
}

//改变目的到文件中，让他自动刷新
pw = new PrintWriter(new BufferedWriter(new FileWriter("myfile\\printwriter.txt")),true);