上代码了解一下:

1 package com.etc; 2  3 import java.io.BufferedInputStream; 4 import java.io.BufferedOutputStream; 5 import java.io.FileDescriptor; 6 import java.io.FileInputStream; 7 import java.io.FileNotFoundException; 8 import java.io.FileOutputStream; 9 import java.io.InputStream;10 import java.io.PrintStream;11 import java.util.Scanner;12 13 /*14  * 对输入输出流进行打印15  * System.in16  * System.out17  * System.err18  * 输入输出重定向:19  * System.setIn(InputStream in)20  * System.setOut(PrintStream out)21  * System.setErr(PrintStream err);22  * 回控制台:23  * FileDescriptor.in24  * FileDescriptor.out25  * FileDescriptor.err26  */27 public class OverideSystem {28 29     public static void main(String[] args) throws FileNotFoundException {30     31         Overide();32         System.out.println("I like codes very much!");33         testPrintStream();    34         console();35         System.out.println("hello,控制台");36     }37     //重定向方法实现38     public static void Overide() throws FileNotFoundException {39         //重定向输出方式及自动更新40         System.setOut(new PrintStream(new BufferedOutputStream(new FileOutputStream("E:/test.txt")),true));41     }42 43     public static void testPrintStream() throws FileNotFoundException {44         //通过文件输入流放入系统的输入，然后再通过Scanner函数将输入结果打印出来45         InputStream in=System.in;46         in=new BufferedInputStream(new FileInputStream("E:/test.txt"));47         Scanner sc=new Scanner(in);48         System.out.println("输出结果:");49         System.out.println(sc.nextLine());50     }51     //返回控制台输出52     public static void console() {53         System.setOut(new PrintStream(new BufferedOutputStream(new FileOutputStream(FileDescriptor.out)),true));54     }55 }

效果截图:

 

 

ps：文章仅作学习了解一用，并未深入，欢迎大佬点评。