PrintStream打印流

PrintWriter（字符）和PrintStream（字节）在打印println功能上几乎一样

// 1、创建一个打印对象
PrintStream ps = new PrintStream("src/d1.txt");
ps.println(97);
ps.println('a');
ps.println("我是打印流");
ps.println(97);
ps.close();

追加数据的方法

 PrintWriter ps = new PrintWriter(new FileOutputStream("src/d1.txt",true));