I canceled that post because in rereading I thought that the problem was
one at a time. Here is it again, in case it didn't get to the OP. I've
done limited testing, so use at your own risk. The main method can be
deleted, it is just for illustration and testing.

Incidentally, I picked extending Writer for two reasons:

1. It has only three abstract methods left to the subclass.

2. It stays in the character processing domain, leaving any character
mapping to get to a Stream to the caller.

import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;

/**
 * Write to multiple Writer instances
 *
 */

public class MultiWriter extends Writer {

  private Writer[] writers;

  /**
   * New MultiWriter for specified writers. Note that flush is
   * only done on explicit call.
   */
  public MultiWriter(Writer... writers) {
    this.writers = new Writer[writers.length];
    for (int i = 0; i < writers.length; i++) {
      this.writers[i] = writers[i];
    }
  }

  @Override
  public void write(char[] cbuf, int off, int len)
      throws IOException {
    for (Writer w : writers) {
      w.write(cbuf, off, len);
      w.flush();
    }
  }

  @Override
  public void flush() throws IOException {
    for (Writer w : writers) {
      w.flush();
    }
  }

  @Override
  public void close() throws IOException {
    for (Writer w : writers) {
      w.close();
    }
  }

  public static void main(String[] args) throws IOException {
    Writer console = new OutputStreamWriter(System.out);
    Writer file = new FileWriter("Testfile.txt");

    Writer dup = new MultiWriter(console, file);
    PrintWriter print = new PrintWriter(dup);

    print.printf("Hello, world");
    print.println();
  }
}