OnJava8-Examples/standardio/Redirecting.java

// standardio/Redirecting.java
// (c)2021 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Demonstrates standard I/O redirection
import java.io.*;

public class Redirecting {
  public static void main(String[] args) {
    PrintStream console = System.out;
    try(
      BufferedInputStream in = new BufferedInputStream(
        new FileInputStream("Redirecting.java"));
      PrintStream out = new PrintStream(
        new BufferedOutputStream(
          new FileOutputStream("Redirecting.txt")))
    ) {
      System.setIn(in);
      System.setOut(out);
      System.setErr(out);
      new BufferedReader(
        new InputStreamReader(System.in))
        .lines()
        .forEach(System.out::println);
    } catch(IOException e) {
      throw new RuntimeException(e);
    } finally {
      System.setOut(console);
    }
  }
}