1.格式化输出到文本文件
PrintWriter out=new PrintWriter(new OutputStreamWriter(new FileOutputStream("xxxx.txt")));
out.printf();//用法和printf一模一样
只是需要记住三者的顺序而已printwriter outputstreamwriter fileoutputstream
2.格式化输出到控制台
System.out.Printf("xxxxxx");//很简单的这个
3.从文本之中读入一行
BufferedReader br=new BufferedReader(new InputStreamReader(new FileInputStream("data.txt")));
只需要记住三者的顺序即可,BufferedReader InputStreamReader FileInputStream