How to use

flushBuffer

method

in

javax.servlet.http.HttpServletResponse

 @Path("/")
@POST
@Consumes({ MediaType.APPLICATION_JSON })
@Produces({ MediaType.APPLICATION_JSON })
public User addUser(User user, @Context final HttpServletResponse response){

  User newUser = ...

  //set HTTP code to "201 Created"
  response.setStatus(HttpServletResponse.SC_CREATED);
  try {
    response.flushBuffer();
  }catch(Exception e){}

  return newUser;
}

 @RequestMapping(value = "/files/{file_name}", method = RequestMethod.GET)
public void getFile(
  @PathVariable("file_name") String fileName, 
  HttpServletResponse response) {
  try {
   // get your file as InputStream
   InputStream is = ...;
   // copy it to response's OutputStream
   org.apache.commons.io.IOUtils.copy(is, response.getOutputStream());
   response.flushBuffer();
  } catch (IOException ex) {
   log.info("Error writing file to output stream. Filename was '{}'", fileName, ex);
   throw new RuntimeException("IOError writing file to output stream");
  }

}

 private void handleBadRequest(HttpServletResponse response, String errorMessage) throws IOException
 {
  if (!response.isCommitted()) {
   response.resetBuffer();
   response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
   jsonMapper.writeValue(response.getOutputStream(), ImmutableMap.of("error", errorMessage));
  }
  response.flushBuffer();
 }
}

response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment; filename=" + URLEncoder.encode(filename, "UTF-8"));
  IOUtils.copy(in, response.getOutputStream());
  response.flushBuffer();

private void doGraph(HttpServletRequest httpRequest, HttpServletResponse httpResponse,
    Range range, String graphName) throws IOException {
  final int width = Math
      .min(Integer.parseInt(HttpParameter.WIDTH.getParameterFrom(httpRequest)), 1600);
  final int height = Math
      .min(Integer.parseInt(HttpParameter.HEIGHT.getParameterFrom(httpRequest)), 1600);
  final String max = HttpParameter.MAX.getParameterFrom(httpRequest);
  final boolean maxHidden = max != null && !Boolean.parseBoolean(max);
  final JRobin jrobin = collector.getJRobin(graphName);
  if (jrobin != null) {
    final byte[] img = jrobin.graph(range, width, height, maxHidden);
    // png comme indiqué dans la classe jrobin
    httpResponse.setContentType("image/png");
    httpResponse.setContentLength(img.length);
    final String fileName = graphName + ".png";
    // encoding des CRLF pour http://en.wikipedia.org/wiki/HTTP_response_splitting
    httpResponse.addHeader("Content-Disposition",
        "inline;filename=" + fileName.replace('\n', '_').replace('\r', '_'));
    httpResponse.getOutputStream().write(img);
    httpResponse.flushBuffer();
  }
}

 public void handle(String pathInContext, Request request, HttpServletRequest httpRequest, HttpServletResponse httpResponse) throws IOException, ServletException {
  int load = 100;
  httpResponse.setStatus(200);
  httpResponse.setContentLength(load);
  httpResponse.setContentType("application/octet-stream");
  httpResponse.flushBuffer();
  OutputStream os = httpResponse.getOutputStream();
  for (int i = 0; i < load; i++) {
   os.write(i % 255);
   try {
    Thread.sleep(300);
   } catch (InterruptedException ex) {
    // nuku
   }
   if (i > load / 10) {
    httpResponse.sendError(500);
   }
  }
  httpResponse.getOutputStream().flush();
  httpResponse.getOutputStream().close();
 }
}

/**
 * Return a single byte to the client.
 * 
 * @param message
 *            Message
 * @param resp
 *            Servlet response
 * @throws IOException
 *             I/O exception
 */
protected void returnMessage(byte message, HttpServletResponse resp) throws IOException {
  log.debug("returnMessage {}", message);
  resp.setStatus(HttpServletResponse.SC_OK);
  resp.setHeader("Connection", "Keep-Alive");
  resp.setHeader("Cache-Control", "no-cache");
  resp.setContentType(CONTENT_TYPE);
  resp.setContentLength(1);
  resp.getWriter().write(message);
  resp.flushBuffer();
}

/**
 * wrapper should set all headers except "content-length"
 */
@Test
public void testHeader() throws IOException {
 wrapper.setStatus(200);
 verify(response).setStatus(200);
 wrapper.addHeader("header", "header value");
 verify(response).addHeader("header", "header value");
 wrapper.addHeader("content-length", "header value2");
 verify(response, never()).addHeader("content-length", "header value");
 wrapper.setIntHeader("header", 5);
 verify(response).setIntHeader("header", 5);
 wrapper.setIntHeader("content-length", 4);
 verify(response, never()).setIntHeader("content-length", 4);
 wrapper.setHeader("set-header", "new value");
 verify(response).setHeader("set-header", "new value");
 wrapper.setHeader("content-length", "content length value");
 verify(response, never()).setHeader("content-length", "content length value");
 wrapper.sendRedirect("location");
 verify(response).sendRedirect("location");
 wrapper.flushBuffer();
 verify(response).flushBuffer();
}

/**
 * Redirect to HTTP port.
 */
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  String host = System.getProperty("http.host");
  String port = System.getProperty("http.port");
  if ("0.0.0.0".equals(host)) {
    host = "127.0.0.1";
  }
  resp.setStatus(HttpServletResponse.SC_MOVED_TEMPORARILY);
  resp.addHeader("Location", "http://" + host + ":" + port);
  resp.setContentType("text/plain");
  String message = "Relocated to http://" + host + ":" + port;
  resp.setContentLength(message.length());
  resp.getWriter().write(message);
  resp.flushBuffer();
}

  protected void process(HttpServletRequest request, HttpServletResponse response)
      throws IOException {
    String resource = request.getPathInfo().replace(request.getServletPath(), "");
    if (resource.startsWith("/"))
      resource = resource.replaceFirst("/", "");
    InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource);
    if (in == null) {
      throw new Error("Cannot find resource " + resource);
    }

    try {
      ByteStreams.copy(in, response.getOutputStream());
    } finally {
      in.close();
      Calendar c = Calendar.getInstance();
      c.setTime(new Date());
      c.add(Calendar.DATE, 10);
      response.setDateHeader("Expires", c.getTime().getTime());
      response.setHeader("Cache-Control", "max-age=864000");
      response.flushBuffer();
    }

  }
}

private void error(HttpServletResponse resp, String message) {
  try {
    resp.setContentType("application/json");
    Map<String, Object> result = new HashMap<>();
    result.put("status", -1);
    result.put("error", message);
    MAPPER.writeValue(resp.getWriter(), result);
    resp.flushBuffer();
  } catch (Exception e) {
    logger.error("return message error");
  }
}

response.setStatus(statusCode);
      response.setHeader(headerName, headerValue);
  session.exportTo(flowFile, response.getOutputStream());
  response.flushBuffer();
} catch (final ProcessException e) {
  session.transfer(flowFile, REL_FAILURE);

public static void write(HttpServletResponse resp, Writer writer, Object obj, JsonFormat format)
    throws IOException {
  resp.setHeader("Cache-Control", "no-cache");
  if (resp.getContentType() == null)
    resp.setContentType("text/plain");
  // by mawm 改为直接采用resp.getWriter()的方式直接输出!
  Json.toJson(writer, obj, format);
  resp.flushBuffer();
}

response.setContentType("application/octet-stream");
response.setHeader("Cache-Control", "no-cache");
    response.getOutputStream(), "UTF-8"));
      response.flushBuffer();
  response.flushBuffer();
  response.flushBuffer();

  @Override
  public Object answer(InvocationOnMock invocation) throws Throwable {
    HttpServletResponse response = (HttpServletResponse) invocation.getArguments()[1];
    response.getOutputStream().write(bytes);
    response.flushBuffer();
    response.setContentType("text/html");
    return null;
  }
}).when(filterChain).doFilter(any(ServletRequest.class), any(ServletResponse.class));

public void handle(String pathInContext, Request request, HttpServletRequest httpRequest, HttpServletResponse httpResponse) throws IOException, ServletException {
 httpResponse.setStatus(200);
 httpResponse.setContentLength(CONTENT_LENGTH_VALUE);
 httpResponse.setContentType(APPLICATION_OCTET_STREAM.toString());
 httpResponse.flushBuffer();
 final boolean wantSlow = httpRequest.getHeader("X-SLOW") != null;
 OutputStream os = httpResponse.getOutputStream();
 for (int i = 0; i < CONTENT_LENGTH_VALUE; i++) {
  os.write(i % 255);
   } else if (wantConnectionClose) {
    httpResponse.getOutputStream().close();
 httpResponse.getOutputStream().flush();
 httpResponse.getOutputStream().close();

/**
 * Return a message to the client.
 * 
 * @param message
 *            Message
 * @param resp
 *            Servlet response
 * @throws IOException
 *             I/O exception
 */
protected void returnMessage(String message, HttpServletResponse resp) throws IOException {
  log.debug("returnMessage {}", message);
  resp.setStatus(HttpServletResponse.SC_OK);
  resp.setHeader("Connection", "Keep-Alive");
  resp.setHeader("Cache-Control", "no-cache");
  resp.setContentType(CONTENT_TYPE);
  resp.setContentLength(message.length());
  resp.getWriter().write(message);
  resp.flushBuffer();
}

resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
resp.setHeader("Connection", "Keep-Alive");
resp.setHeader("Cache-Control", "no-cache");
resp.flushBuffer();

  request.getMethod().equalsIgnoreCase("OPTIONS")) {
 response.sendError(HttpServletResponse.SC_FORBIDDEN);
 response.flushBuffer();
 ((Request) request).setHandled(true);
 return;
 response.setContentType("text/html;charset=utf-8");
 response.setStatus(HttpServletResponse.SC_OK);
 response.getWriter().write("For Flume metrics please click"
     + " <a href = \"./metrics\"> here</a>.");
 response.flushBuffer();
 ((Request) request).setHandled(true);
 return;
} else if (target.equalsIgnoreCase("/metrics")) {
 response.setContentType("application/json;charset=utf-8");
 response.setStatus(HttpServletResponse.SC_OK);
 Map<String, Map<String, String>> metricsMap = JMXPollUtil.getAllMBeans();
 String json = gson.toJson(metricsMap, mapType);
 response.getWriter().write(json);
 response.flushBuffer();
 ((Request) request).setHandled(true);
 return;
response.flushBuffer();

/**
 * 导出model的png文件
 */
@RequestMapping(value = "/model/export/image/{modelId}", method = RequestMethod.GET)
public void exportPng(@PathVariable("modelId") String modelId, HttpServletResponse response) {
  try {
    Model modelData = repositoryService.getModel(modelId);
    byte[] pngBytes = repositoryService.getModelEditorSourceExtra(modelData.getId());
    ByteArrayInputStream in = new ByteArrayInputStream(pngBytes);
    IOUtils.copy(in, response.getOutputStream());
    String filename = modelData.getKey() + ".process.model.png";
    response.setHeader("Content-Disposition", "attachment; filename=" + filename);
    response.flushBuffer();
  } catch (Exception e) {
    LOGGER.error("导出model的png文件失败：modelId={}", modelId, e);
  }
}