MessagePanelPolling function is called through a wicket page, the wicket
page has an active ajax call to the async servlet,
public BasePage(PageParameters pageParameters) {
super(pageParameters);
add(new MessageCheckBehaviour());
}
static class MessageCheckBehaviour extends MyJqueryBehaviour{
@Override
public void renderHead(Component component, IHeaderResponse response) {
super.renderHead(component, response);
//response.render(OnLoadHeaderItem.forScript("MessagePanel.longPoll('"+UserContextHolder.getUser().getInfUser().getSysUserId().toString()+"')"));
response.render(JavaScriptHeaderItem.forReference(JS_FILE));
}
static final PackageResourceReference JS_FILE= new
JavaScriptResourceReference(MyJqueryBehaviour.class, "messagePolling.js");
}
Async servlet waits on a blocking queue , a new item in queue causes
thread to checks all registered AsyncContext's and if match found, write
to the aynscontext response.
public class MessageNotificationServlet extends HttpServlet {
static Logger logger=
Logger.getLogger(MessageNotificationServlet.class);
private Queue<AsyncContext> asyncContexts = new
ConcurrentLinkedQueue<AsyncContext>();
static BlockingQueue<String> messages = new
LinkedBlockingQueue<String>();
ExecutorService executorService;
public static void addMessage(String msg){
try{
messages.add(msg);
}catch(Exception e){
throw new RuntimeException(e);
}
}
@Override
public void init(ServletConfig config) throws ServletException {
super.init(config);
executorService=Executors.newSingleThreadExecutor();
executorService.submit(new Runnable() {
@Override
public void run() {
while(true){
try{
String message =
messages.take();
for(AsyncContext asyncContext
:asyncContexts ){
try{
if(asyncContext.getRequest().getParameter("name").trim().equals(message)){
String
paramName=asyncContext.getRequest().getParameter("name").trim();
String
timestamp=asyncContext.getRequest().getParameter("timestamp").trim();
try{
PrintWriter printWriter=asyncContext.getResponse().getWriter();
printWriter.println("new_message");
printWriter.flush();
asyncContext.complete();
}catch(Exception e){
logger.debug(" failed writing to async "+paramName +"
"+timestamp );
logger.error((" async failed "+paramName +" "+timestamp),e);
}
}
}catch (Exception e) {
asyncContexts.remove(asyncContext);
logger.debug("
error with asyncontext ",e);
}
}
}catch(Exception e){
logger.debug(" error in msg
check thread ",e);
}
}
}
});
}
@Override
public void destroy() {
super.destroy();
messages.clear();
asyncContexts.clear();
executorService.shutdownNow();
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse
response)
throws ServletException, IOException {
String name=req.getParameter("name");
AsyncContext asyncContext=req.startAsync();
asyncContexts.stream().filter(as->as.getRequest().getParameter("name").equals(name)).collect(Collectors.toList()).forEach(ac->ac.complete());
asyncContext.getRequest().setAttribute("start_time",
new Date());
asyncContext.addListener(new AsyncListener() {
@Override
public void onTimeout(AsyncEvent event) throws
IOException {
logger.debug(" timeout occuered for "
+event.getAsyncContext().getRequest().getParameter("name") +"
"+event.getAsyncContext().getRequest().getParameter("timestamp")+"
"+event.getAsyncContext().getRequest().getAttribute("start_time"));
event.getAsyncContext().complete();
}
@Override
public void onStartAsync(AsyncEvent event)
throws IOException {
logger.debug(" onstart for "
+event.getAsyncContext().getRequest().getParameter("name") +"
"+event.getAsyncContext().getRequest().getParameter("timestamp") +"
"+event.getAsyncContext().getRequest().getAttribute("start_time"));
}
@Override
public void onError(AsyncEvent event) throws
IOException {
logger.debug(" error occuered for "
+event.getAsyncContext().getRequest().getParameter("name") +"
"+event.getAsyncContext().getRequest().getParameter("timestamp") +"
"+event.getAsyncContext().getRequest().getAttribute("start_time"));
asyncContexts.remove(event.getAsyncContext());
}
@Override
public void onComplete(AsyncEvent event) throws
IOException {
logger.debug(" completed "
+event.getAsyncContext().getRequest().getParameter("name")+"
"+event.getAsyncContext().getRequest().getParameter("timestamp") +"
"+event.getAsyncContext().getRequest().getAttribute("start_time"));
asyncContexts.remove(event.getAsyncContext());
}
});
asyncContext.setTimeout(TimeUnit.MINUTES.toMillis(60));
asyncContexts.add(asyncContext);
}
}
--
View this message in context:
http://apache-wicket.1842946.n4.nabble.com/open-connection-to-async-servlet-and-initiate-wicket-ajax-request-results-ComponentNotFoundException-tp4674357p4674362.html
Sent from the Users forum mailing list archive at Nabble.com.
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
