PrintStream write(String) method

void executeScript(String script, PrintStream ps) throws IOException
{
  String cmd = "source " + script;
  Process p = Runtime.getRuntime().exec(cmd);
  BufferedReader reader = new BufferedReader( new InputStreamReader( p.getInputStream() ) );

  String output = reader.readLine();

  while (output != null)
  {
    ps.write(output);
    output = reader.readLine();
  } // end while

} // end executeScript(File, PrintStream)

Any reason why "ps.write(output)" gives:
    write(java.lang.String) has private access in java.io.PrintStream