Servlets :: Setting A Timer Task Even If Server Restarts
Jun 10, 2014
I have a web app that accepts requests. Once a request is sent, I want to create a thread that will sleep for several days if no user action is taken on the request to remind the user to do something. The problem is, how do I ensure the timer will pick up at the same place if the server is restarted? Would serializing the thread do that? I'm guessing no because I think you're just creating a new instance at start up. Just checking If there's anything built into Java to do this.
I have written the java code using timer class to schedule the task , but i am getting error as } expected, i am not able to figure out the error, I have placed the { opening and closing curly bracket everywhere but still it is giving me error.
I am developing an app with a Java Servlet backend, and I am trying to get the Async call (AsyncTask - Android Developers) to get my response message Synced with the rest of the client and being able use this information wherever I want. Without a callback method, when from the caller class I use the commands:
ServletPostAsyncTask s = new ServletPostAsyncTask(); s.execute(new Pair<Context, String>(ListViewPrenota.this, "tours")); Tours ttours = s.tours; Tour tour = ttours.getTours().get(0);
I receive a NullPointerException pointing to the third line Tours ttours = s.tours;, since the s.execute() method doesn't wait for the rest of the lines to get executed.To solve this I thought about implementing a callback method with interfaces in Java, but I am not sure on how to do it. For example, what class does have to implement the interface, the ServletPostAsyncTask or the caller class?
Our company has a web based project which using the Jboss EAP 6.1 +EJB 3.1 + JSF2 and deployed it in a cluster environment(Server A,Server B and Server C).We have created some schedule tasks by using EJB timer service and the timer data file is stored in a central file system.And users can login and access to a task configuration page to customise his own tasks by create,update,delete actions etc.But we find that the timers don't work correctly in the cluster environment.
For example.When we start the Servers(A,B,C),each server will load the timer file data into his own node cache from the central file system.But when one user go to the task configuration page to update or delete his own tasks from one of the Servers, it only update the change on its own node cache and don't replicate the timer data to other nodes' cache and which cause the problem.
I know there is one way to fix it is that we could shutdown the three Servers and re-boot them and the timer data file will be re-loaded into each server's cache. But we can't do that because the users want their own created/updated tasks take effect immediately once they change them.My question is that when the timer data in cache is updated on one server, how to make it synchronize to the other Servers'.
I am working on a chess game. I need to construct a game room where all the player are present and room chat is up. Also some tables where games are being played. Now my question is how to create this game room?
To me this room must need to be like static or global (if I am not mistaken) that is up when server starts and players can join this room and should be down when server is done. How can I implement such room that would stay up for infinite time.
I have two java classes, the first is a Servlet that register users access to the same servlet, the second class implements a ServletContextListener and update the HashMap removing the expired access.I need this Application to obtain a list of online users on an android app, this is the code:
I am using servlet 2.4 I used the ff. code below to set httponly in my application's cookies but it did not work. When I do a javascrip alert (document. cooke) in my page, the session id still shows up.
I am new to Servlets and came across it in Head First Java 2nd Edition. I wrote the servlet code. I don't know how to run it. Do I need to set up a server?
If we have request which hit the server, before it reaches servlet or the response going to send the browsers, through how many components it pass through (or the process flow).
i want to publish data from my application to mobile devices as calendar-events and back.therefore i want to write an application (webservice, servlet,???), which i then can add as a new account in my e.g. android device' calendar.
shortly: my application should simulate an exchange-/activesync-server, since on "all" mobile devices i can add exchange accounts.is/are there any documentation, libraries,
Why we need to use ServletContext attribute when we already have ServletContext parameters.Whats the difference between ServletContext Attributes and ServletContext parameters.
I'm new to json and the web. My purpose is to use json data from a server and parse it and show meaningful data to the user. I am aware of json parsing, so no sweat there. However, I would like to know how json data is sent to the front end after which it can be parsed.
Usually in my json parsing examples, I have a variable like var data = ]OR I do a getJSON on a data.json file which I have stored in the project folder. However, I want this data to come real time from a servlet. How to go about this?
So, basically my question is, how do I send real time json data from a servlet backend, say some records which I have extracted from the database using jdbc?
I would like to know how we can deploy one Web application on multiple server to share the work between them? My first thought is that we just deploy the same war file on different servers that connect to the same database. However, what will happen when a user enter something like [URL]? How can multiple servers share the same domain name and how the requests from different users are redirected to these different server?
How the server know the device type from which request came from. I have requirement to implement the logic based on the type of the device. Eg: Mobile, TAB, PC or Laptop. Is there any existing API in Jquery to know the details about the client?
I write a Client/Server program,trying to send and receive a object between client and server. I use the ObjectStream but there exists an EOFException on the client side when invoking readObject() .... I've tried many times but couldn't figure it out ...
server-side code
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { try{ ObjectOutputStream out = new ObjectOutputStream(resp.getOutputStream()); ObjectInputStream in = new ObjectInputStream(req.getInputStream()); PersonalData pe = (PersonalData)in.readObject(); System.out.println(pe.getYearlySalary());
I need to write server side program(Servlet) which must be access by several requests at same time.how to handle this using java? Do i need to use queue or multiple instance of same class. Any example server method which returns the results based on ID
public String getResut(int id){
1)get db connection 2)get the result from db 3) retun the result }
When do i get IllegalStateException in servlets.What it means by trying to write to the output stream (response) after the response has been committed by server. What it means by committing response and uncommitting response. cannot i send uncommitted response.
I would like to know the details about how a server handles a multipart request. I know that a webserver comprises of a HTTP adapter(which is responsible for receiving http requests and sending http responses) and a container(which is responsible for handling dynamic requests).
So, when a client sends a request, the HTTP adapter receives it. Then transfers the request to the container if the http adapter cannot handle it(jsps, servlets for example).
Suppose, a client sends a multipart request which has an avi file of size upto 100mb. For example, lets assume that the client takes 5 minutes to upload the file.
Lets also assume that my application is only interested in flv files. Is there any way to stop/terminate the multipart request before the file is transferred to the server? So that the client's time will not be wasted?
I think that the HTTP adapter will transfer the request to the container only after receiving the entire request, i.e. the servlet will be called only after the file is transferred to the server from client. Is it right?
If its right then there is no easy way to terminate the multipart request unless the entire file is transferred to the server. Is this right?
How does web server differentiates between request for static web page and request for dynamic web page? i think if web server receives request for static page directly renders that to server or else if request is for dynamic web page passes that to web app which processes the request and renders that to client. bUT how does web server differentiates between both the request.
Is there any kind of way to generate HTTP request within a servlet, dispatch it to the server and get back the answer delivered to the servlet? Or are the servlets meant only to respond to passed requests, not generate them?
(I asked a similar question here: [Code] ..... but no luck)
I am currently working on a module where huge amount of data needs to be sent to the weblogic server. The limit on Weblogic-> Server - > Protocols is 10MB.
The huge data is coming when i try to add more than 20 rows to the Ajax request.
There are possible two solutions for this
1) Increase the limit on Weblogic server to 1Gb which might lead to server crash when two or more users are trying to add 100 records at the same time. 2) Send memory in the form of chunks of (length of a row) every time I add a row. Store this in session and upon form submission retrieve from session. This cannot work if there are more than 20 users doing load testing as increase in session data decrease performance gradually.
I need that data passed to my server without any performance or errors.Currently its showing weblogic.socket.MaxMesssageSizeExceededException and RequestURI too long errors.
Since musicians are supposed to use ALL free services available to them in order to promote themselves, every time we book a show I have to: update facebook, update reverbnation, update bandcamp, etc.
So I was trying to find a way to automate this task, and I found a way to output my facebook page's events to an ical file (which I can port into Google Calendars if I wish). ReverbNation and Bandcamp unfortunately don't offer any integration with anything at all period... So this is what I wanted to write some code to do (see flowchart thing).
