private void fill() throws IOException {
  int i=in.read(buf,0,buf.length);
  if (i > 0) {
    pos=0;
    count=i;
  }
}

private void fill ( ) throws IOException { int i = in . read ( buf , 0 , buf . length ) ; if ( i > 0 ) { pos = 0 ; count = i ; } }
fill up our buffer from the underlying input stream . users of this method must ensure that they use all characters in the buffer before calling this method .
