learning java 重定向标准输入输出

output redirectionOut:

public class RedirectOut {

    public static void main(String[] args) throws FileNotFoundException {

        try {

            var ps = new PrintStream(new FileOutputStream("out.txt"));

            System.setOut(ps);

            System.out.println("普通字符串");

            System.out.println(new RedirectOut());

        } catch (FileNotFoundException e) {

            e.printStackTrace();

        }

    }

}

input redirectionIn:

public class RedirectionIn {

    public static void main(String[] args) {

        try {

            var fis = new FileInputStream("./src/com/company/RedirectionIn.java");

            System.setIn(fis);

            var sc = new Scanner(System.in);

            sc.useDelimiter("\n");

            while (sc.hasNext()){

                System.out.println("键盘输入的内容是：" + sc.next());

            }

        } catch (FileNotFoundException e) {

            e.printStackTrace();

        }

    }

}