Transforming to linux-style stream

Why there are differences between the platforms end of line characters? Oh yes, Never ask the WHY question on standarts, so I found my self coding a small block to overcome this mini-crisis:

// given an input stream
final InputStream is = ...;

// create a stream that behaves as a linux-style stream
InputStream linuxStream = new InputStream() {
 int previous = -1;
 int current = -1;
 int next = -1;    

  public int read() throws IOException {
   if (next != -1) {// a buffered int was readen last iteration
      current = next;
      next = -1;
   } else { // else read an int from the stream
     current = is.read();
   }

    if (current == 13) {
        next = is.read();
        if (next == 10) { // encounter "\r\n" transform to "\n"
            next = -1;
        }
        current = 10;
    }
    return previous = current;
  }
}