重定向标准输入和输出

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.util.Scanner;

public class RedirectTest {
    public static void main(String[] args) {
        try (PrintStream printStream = new PrintStream(new FileOutputStream("out.txt"))) {
            System.setOut(printStream);
            System.out.println("重定向之后");
            System.out.println(new RedirectTest());
            try (FileInputStream fileInputStream = new FileInputStream("src/RedirectTest.java")) {
                System.setIn(fileInputStream);
                Scanner sc = new Scanner(System.in);
                while (sc.hasNextLine()) {
                    System.out.println(sc.nextLine());
                }
            }catch (Exception e){
                e.printStackTrace();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}