IO流必知必会(9)——重定向标准输入/输出流

System类中提供了重定向标准输入、输出的方法。

public class RedirectOut {
    public static void main(String[] args) {
        try (PrintStream ps = new PrintStream(new FileOutputStream("out.txt"))) {
            // redirect the output to ps
            System.setOut(ps);
            System.out.println("hello");
            System.out.println(new RedirectOut());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

    public class RedirectIn {
        public static void main(String[] args) {
            try (FileInputStream in = new FileInputStream(
                    "src/inputandoutput/RedirectIn.java")) {
                System.setIn(in);
                Scanner scan = new Scanner(System.in);
                // only use \n as Delimiter
                scan.useDelimiter("\n");
                while (scan.hasNext()) {
                    System.out.println("content:" + scan.next());
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }