ChunkedOutput returning response on browser all at once

Question

I am using org.glassfish.jersey.server.ChunkedOutput to get the chunked response to my request. When I hit the URL through browser, instead of getting output as separate chunks, I am getting all the chunks at once. But when I use a Test Client to hit the resource, I get the output as separate chunks.

Server Used: Glassfish 4.0 Jersey version 2.13

Resource method is as follows:

@GET
@Path("chunk")
public ChunkedOutput<String> getChunkedResponse(@Context HttpServletRequest request) {

    final ChunkedOutput<String> output = new ChunkedOutput<String>(
            String.class);

    new Thread() {
        public void run() {
            try {
                Thread.sleep(2000);
                String chunk;
                String arr[] = { "America\r\n", "London\r\n", "Delhi\r\n", "null" };
                int i = 0;
                while (!(chunk = arr[i]).equals("null")) {
                    output.write(chunk);
                    i++;
                    Thread.sleep(2000);
                }
            } catch (IOException e) {
                logger.error("IOException : ", e);
            } catch (InterruptedException e) {
                logger.error("InterruptedException : ", e);
                e.printStackTrace();
            } finally {
                try {
                    output.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    logger.error("IOException IN finally : ", e);
                }
            }
        }
    }.start();

    // the output will be probably returned even before
    // a first chunk is written by the new thread
    return output;
}

Test Client method is as follows:

  private static void testChunkedResponse(WebTarget target){
      final Response response = target.path("restRes").path("chunk")
                .request().get();
        final ChunkedInput<String> chunkedInput =
                response.readEntity(new GenericType<ChunkedInput<String>>() {});
        String chunk;
        while ((chunk = chunkedInput.read()) != null) {
            logger.info("Next chunk received: " + chunk);
        }
  }

Can someone please help me understand why response is not getting chunked on browser and what can be done about it?

Answer 1

I am also working on the client to process the chunkedouput response. From my knowledge,

1. For browser, you need to write longer string, i am not sure why, but seems for firefox, there is a buffer, so unless the buffer size get met, the browser wont rendering the html. From my test on Chrome, you can see the effect for short strings.
2. for the chunkedInput, there is a parser keep searching for separator for the string. Since using Jersey, ChunkedInput wont be able to how to split the stream. it use the parser to split and return splited substring when you call read(). By default, the separator is '\r\n', if you write '\r\n' to your chunkedoutput, you should see the client code run as you expected.

Answer 2

I had the same problem. Adding line separator when writing solved the problem.

output.write(chunk + System.lineSeparator());