Servlet seems to handle multiple concurrent browser requests synchronously

Question

As far as I know Java Servlets are handling multiple requests concurrently and I've searched through StackOverflow as well as Google, and confirmed what I thought. However I am quite confused right now, I wrote a simple servlets that seem to show blocking behaviour.

so I have a simple Servlet:

public class MyServlet extends HttpServlet  {     private static final long serialVersionUID = 2628320200587071622L;      private static final Logger logger = Logger.getLogger(MyServlet.class);      @Override     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException      {         logger.info("[doGet] Test before");          try {             Thread.sleep(60000);         } catch (InterruptedException e) {             // TODO Auto-generated catch block             e.printStackTrace();         }         logger.info("[doGet] Test after");          resp.setContentType("text/plain");         resp.getWriter().write("OK");      } } 

Then I have 2 browser windows, I opened at the same time that hit my Servlet. And the result is the first request blocking the 2nd one. The log also shows:

10:49:05,088 [http-8383-Processor14]  INFO MyServlet - [doGet] Test before 10:50:05,096 [http-8383-Processor14]  INFO MyServlet - [doGet] Test after 10:50:05,106 [http-8383-Processor22]  INFO MyServlet - [doGet] Test before 10:51:05,112 [http-8383-Processor22]  INFO MyServlet - [doGet] Test after 

I feel like I am missing something ... Servlets supposed to be able to handle concurrent request, but it doesnt seem to be doing it. I also did the same as above on the service method instead of doGet and it does the same thing.

Any pointers?

Thanks

Answer 1

Your browser is apparently using the same HTTP connection in different windows. The servlet container uses a single thread per HTTP connection, not per HTTP request. You should run two physically different webbrowsers to test this properly. E.g. one Firefox and one Chrome.