if (offset < 0 || len < 0 || offset + len > buf.length) throw new ArrayIndexOutOfBoundsException ();  ch.write (buf, offset, len);
ch.write (b);
  public void write (byte[] buf, int offset, int len)    throws IOException  {    if (offset < 0        || len < 0        || offset + len > buf.length)      throw new ArrayIndexOutOfBoundsException ();        ch.write (buf, offset, len);  }