Java I/O How to - Redirect standard error to a file

Question

We would like to know how to redirect standard error to a file.

Answer

// w  ww.j av  a2s . c  o  m
import java.io.FileOutputStream;
import java.io.PrintStream;

public class Main {
  public static void main(String[] args) throws Exception {
    System.setErr(new PrintStream(new FileOutputStream("system_err.txt")));

    String nullString = null;
    nullString = nullString.toUpperCase();
  }
}