public void sendResponseHeaders(int rCode, long contentLen) throws IOException {
   if (sentHeaders) {
     throw new IOException("headers already sent");
   }
   this.rcode = rCode;
   String statusLine = "HTTP/1.1 " + rCode + Code.msg(rCode) + "\r\n";
   OutputStream tmpout = new BufferedOutputStream(ros);
   PlaceholderOutputStream o = getPlaceholderResponseBody();
   tmpout.write(bytes(statusLine, 0), 0, statusLine.length());
   boolean noContentToSend = false; // assume there is content
   rspHdrs.set("Date", df.format(new Date()));
   if (contentLen == 0) {
     if (http10) {
       o.setWrappedStream(new UndefLengthOutputStream(this, ros));
       close = true;
     } else {
       rspHdrs.set("Transfer-encoding", "chunked");
       o.setWrappedStream(new ChunkedOutputStream(this, ros));
     }
   } else {
     if (contentLen == -1) {
       noContentToSend = true;
       contentLen = 0;
     }
     /* content len might already be set, eg to implement HEAD resp */
     if (rspHdrs.getFirst("Content-length") == null) {
       rspHdrs.set("Content-length", Long.toString(contentLen));
     }
     o.setWrappedStream(new FixedLengthOutputStream(this, ros, contentLen));
   }
   write(rspHdrs, tmpout);
   this.rspContentLen = contentLen;
   tmpout.flush();
   tmpout = null;
   sentHeaders = true;
   if (noContentToSend) {
     WriteFinishedEvent e = new WriteFinishedEvent(this);
     server.addEvent(e);
     closed = true;
   }
   server.logReply(rCode, req.requestLine(), null);
 }
 @Override
 public void handle(HttpExchange t) throws IOException {
   if (RemoteUtil.deny(t)) {
     throw new IOException("Access denied");
   }
   String id = RemoteUtil.getId("thumb/", t);
   LOGGER.trace("web thumb req " + id);
   if (id.contains("logo")) {
     RemoteUtil.sendLogo(t);
     return;
   }
   RootFolder root = parent.getRoot(RemoteUtil.userName(t), t);
   if (root == null) {
     LOGGER.debug("weird root in thumb req");
     throw new IOException("Unknown root");
   }
   final DLNAResource r = root.getDLNAResource(id, root.getDefaultRenderer());
   if (r == null) {
     // another error
     LOGGER.debug("media unknown");
     throw new IOException("Bad id");
   }
   InputStream in;
   if (!configuration.isShowCodeThumbs() && !r.isCodeValid(r)) {
     // we shouldn't show the thumbs for coded objects
     // unless the code is entered
     in = r.getGenericThumbnailInputStream(null);
   } else {
     r.checkThumbnail();
     in = r.getThumbnailInputStream();
   }
   Headers hdr = t.getResponseHeaders();
   hdr.add("Content-Type", r.getThumbnailContentType());
   hdr.add("Accept-Ranges", "bytes");
   hdr.add("Connection", "keep-alive");
   t.sendResponseHeaders(200, in.available());
   OutputStream os = t.getResponseBody();
   LOGGER.trace("input is {} output is {}", in, os);
   RemoteUtil.dump(in, os);
 }
 void write(Headers map, OutputStream os) throws IOException {
   Set<Map.Entry<String, List<String>>> entries = map.entrySet();
   for (Map.Entry<String, List<String>> entry : entries) {
     String key = entry.getKey();
     byte[] buf;
     List<String> values = entry.getValue();
     for (String val : values) {
       int i = key.length();
       buf = bytes(key, 2);
       buf[i++] = ':';
       buf[i++] = ' ';
       os.write(buf, 0, i);
       buf = bytes(val, 2);
       i = val.length();
       buf[i++] = '\r';
       buf[i++] = '\n';
       os.write(buf, 0, i);
     }
   }
   os.write('\r');
   os.write('\n');
 }