Image Servlet for JSF Project "Locking" the Application Server

Question

I have the following code that provides my portal with the images that are in the database

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
    String id = req.getParameter("id");


    if(id.equals("logo")){
        resp.setContentType(museu.getConfiguracao().getContentTypeLogo());
        resp.getOutputStream().write(museu.getConfiguracao().getLogo());

    }else if(req.getParameter("slide")!=null){
        resp.setContentType(banco.getSlide(id).getContentType());
        resp.getOutputStream().write(banco.getSlide(id).getContent());

    }
    else{
        Foto foto = museu.getFoto(Long.parseLong(id));
        resp.setContentType(foto.getContentType());
        resp.getOutputStream().write(foto.getContent());
    }
}

The problem, when I try to request 3/4 or more images to the same page, the application server (Glassfish) simply "hangs" and after a while releases the error, the images are usually loaded a little (about 10%, another 50%) but simply the server "hangs" out of nowhere. Headers of Log Errors:

2014-03-21T08:58:20.561-0300|Grave: java.io.IOException: java.util.concurrent.TimeoutException
at org.glassfish.grizzly.utils.Exceptions.makeIOException(Exceptions.java:81)

Caused by: java.util.concurrent.TimeoutException
at java.util.concurrent.FutureTask.get(FutureTask.java:201)
at org.glassfish.grizzly.http.io.OutputBuffer.blockAfterWriteIfNeeded(OutputBuffer.java:951)
... 36 more

2014-03-21T08:58:20.567-0300|Advertência: StandardWrapperValve[MultiMidiaServlet]: Servlet.service() for servlet MultiMidiaServlet threw exception
java.io.IOException: java.util.concurrent.TimeoutException

Caused by: java.util.concurrent.TimeoutException
at java.util.concurrent.FutureTask.get(FutureTask.java:201)
at org.glassfish.grizzly.http.io.OutputBuffer.blockAfterWriteIfNeeded(OutputBuffer.java:951)
... 36 more

Answer 1

I had to do it once. What I’m finding it rather strange is the Glassfish "lock" in some photos and work in others. Is that right? Anyway, it follows the code that I used to do almost the same thing to you. Only in my Servlet there is integration with the Spring that you can ignore.

Anyway, it’s not complicated to understand. Try to adapt your need and see if it works.

The functioning of that Servlet is basically to search a photo in the database (oracle) where the photo column is a blob. I’m using JPA, then the entity for the photo is ColaboradorFoto.

The call from that Servlet would look like this: http://www.example.com/foto?matricula=123456 for example. The photo would appear in the browser.

@Component("fotoServlet")
@WebServlet("/foto")
public class FotoServlet extends HttpServlet {

    private static final long serialVersionUID = -7451359765915659089L;
    private static final Logger logger = LogManager.getLogger(FotoServlet.class);

    public FotoServlet() {
        super();
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String matricula = request.getParameter("matricula");

        if (matricula != null && !matricula.isEmpty()) {
            OutputStream o = response.getOutputStream();
            response.setContentType("image/jpg");

            WebApplicationContext springContext = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
            ColaboradorService colaboradorService = springContext.getBean(ColaboradorService.class);

            try {
                ColaboradorFoto colabFoto = colaboradorService.getColaboradorFoto(Long.parseLong(matricula));
                if (colabFoto != null && colabFoto.getFoto() != null) {
                    byte[] imgData = colabFoto.getFoto();
                    o.write(imgData);
                }
                else {
                    o.write(this.getFotoDefault());
                }

            }
            catch (ServiceException e) {
                o.write(this.getFotoDefault());
                logger.error("Erro ao obter a foto do colaborador no banco de dados", e);
            }
            catch (NumberFormatException e) {
                o.write(this.getFotoDefault());
                logger.warn("Matricula passada nao contem somente numeros. Retornando foto default", e);
            }

            o.flush();
            o.close();
        }
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request, response);
    }

    private byte[] getFotoDefault() {
        InputStream input = getServletContext().getResourceAsStream("/resources/images/sem_foto.png");

        try {
            return IOUtils.toByteArray(input);
        }
        catch (IOException e) {
            logger.error("Erro ao tentar obter foto padrao para colaborador", e);
            return null;
        }
    }
}