I am working on making a scheduler, just like Windows Scheduler using Quartz.Net.
In Windows Scheduler, there is an option to stop a task from running if it takes more than the specified time. I have to implement the same in my scheduler.
But I am not able to find any extension method/setting to configure Trigger or Job accordingly.
I request some inputs or suggestions for it.
You can write small code to set a custom timout running on another thread. Implement IInterruptableJob interface and make a call to its Interrupt() method from that thread when the job should be interrupted. You can modify the following sample code as per your need. Please make necessary checks/config inputs wherever required.
public class MyCustomJob : IInterruptableJob
{
private Thread runner;
public void Execute(IJobExecutionContext context)
{
int timeOutInMinutes = 20; //Read this from some config or db.
TimeSpan timeout = TimeSpan.FromMinutes(timeOutInMinutes);
//Run your job here.
//As your job needs to be interrupted, let us create a new task for that.
var task = new Task(() =>
{
Thread.Sleep(timeout);
Interrupt();
});
task.Start();
runner = new Thread(PerformScheduledWork);
runner.Start();
}
private void PerformScheduledWork()
{
//Do what you wish to do in the schedled task.
}
public void Interrupt()
{
try
{
runner.Abort();
}
catch (Exception)
{
//log it!
}
finally
{
//do what you wish to do as a clean up task.
}
}
}
Related
I'm trying to get a responsive JavaFX graphical interface while executing a cmd command.
The command I'm executing is the following.
youtube-dl.exe --audio-format mp3 --extract-audio https://www.youtube.com/watch?v=l2vy6pJSo9c
As you see this is a youtube-downloader that converts a youtube link to an mp3-file.
I want this to be executed in a second thread and not in the main FX thread.
I've solved this by implementing interface Callable in the class StartDownloadingThread.
#Override
public Process call() throws Exception {
Process p = null;
p = ExecuteCommand(localCPara1, localCPara2, localDirectory).start();
try {
Thread.sleep(30);
}catch (InterruptedException e){}
return p;
}
The method ExecuteCommand just returns a ProcessBuilder object.
I try to use Thread.sleep to make the program return to the main thread and thus making the application responsive. Unfortunately the program still freezes.
This is how the method call is called.
ExecutorService pool = Executors.newFixedThreadPool(2);
StartDownloadingThread callable = new StartDownloadingThread(parameter1, parameter2, directory);
Future future = pool.submit(callable);
Process p = (Process) future.get();
p.waitFor();
How do I make my GUI responsive using the interface Callable?
Using a executor to run a task just for you to use the get method of the Future that is returned when submitting the task does not actually free the original thread to continue with other tasks. Later you even use the waitFor method on the original thread, which is likely to take even more time than anything you do in your Callable.
For this purpose the Task class may be better suited, since it allows you to handle success/failure on the application thread using event handlers.
Also please make sure an ExecutorService is shut down after you're done submitting tasks.
Task<Void> task = new Task<Void>() {
#Override
protected Void call() throws Exception {
Process p = null;
p = ExecuteCommand(localCPara1, localCPara2, localDirectory).start();
// why are you even doing this?
try {
Thread.sleep(30);
}catch (InterruptedException e){}
// do the rest of the long running things
p.waitFor();
return null;
}
};
task.setOnSucceeded(event -> {
// modify ui to show success
});
task.setOnFailed(event -> {
// modify ui to show failure
});
ExecutorService pool = Executors.newFixedThreadPool(2);
pool.submit(task);
// add more tasks...
// shutdown the pool not keep the jvm alive because of the pool
pool.shutdown();
I got some operations in my Controller class which could take some time. So I want to show a loading dialog while this operation is running.
I tried this:
Platform.runLater(new Runnable() {
#Override
public void run() {
loadingDialog.show();
}
});
Boolean opSuccess = myService.operate();
Platform.runLater(new Runnable() {
#Override
public void run() {
loadingDialog.hide();
}
});
if (opSuccess) {
// continue
}
Now, the Problem is, the loadingDialog is never show. The UI only blocks for some time and than continues on "//continue".
So it seems, the runLater call is blocked by the blocking operation (operate)?
I also tried CoundDownLatch, to wait for loadingDialog.show() to complete, before running myService.operate(). But the latch.await() method never completes.
So my question is, how my I show the loadingDialog until myService.operate() finished and returned true or false? Do I have to put the operate() call into another thread and run it async or is there an easier way?
Thanks for help.
Are you sure your entire code does not run in the JavaFX Thread?
Methods of your controller class usually do and I assume it due to your description.
However, better use the Task class. Here you'll find a tutorial and a short snippet for your application:
// here runs the JavaFX thread
// Boolean as generic parameter since you want to return it
Task<Boolean> task = new Task<Boolean>() {
#Override public Boolean call() {
// do your operation in here
return myService.operate();
}
};
task.setOnRunning((e) -> loadingDialog.show());
task.setOnSucceeded((e) -> {
loadingDialog.hide();
Boolean returnValue = task.get();
// process return value again in JavaFX thread
});
task.setOnFailed((e) -> {
// eventual error handling by catching exceptions from task.get()
});
new Thread(task).start();
I assumed Java 8 and the possibility to use Lambda expressions. Of course it is possible without them.
You are better off making use of concurrency mechanisms/Worker interfaces in JavaFx - Tasks and services instead of using Platform.runLater(). The tasks and services allow you to manage the long running tasks in a separate thread. They also provide callbacks to indicate the progress of the tasks.
You could explore further at http://docs.oracle.com/javafx/2/threads/jfxpub-threads.htm
Also have a look at the Ensemble JavaFX samples for Tasks and Services - http://www.oracle.com/technetwork/java/javase/overview/javafx-samples-2158687.html
I wanted to checking my database table for periodically.So how can i create a webservice and how can i configure it.
basically what you need is, something which is always running and hence can make periodic calls.
There are a number of ways to do it
(Since ASP.NET hence) You can make a Windows Service, and host this service on your server, since server is always running, this Windows Service will make request to your webservice, update database or watever you want
You can use SQL Jobs to do it. You can call a webservice from a job, through a SSIS (Sql Server Integration Service) Package. These packages are very very robust in nature, they can do almost any db activity that you want them to do, including webservice request.
And finally, you can use third party tools such as Quartz.Net
References:
this is how you can call a webservice through a windows service.
this is how you can call a webservice through a ssis package.
this is how you can integrate a SSIS package in a SQL Job
this is how you can create a windows service
this is how you can create a SSIS package
this is how you can get answer/tutorial of almost anything
Example:
simplest of all of these would be a Windows Service. Making a windows service and hosting it on the machine(server) is very easy, use one of the given links (specially the last link). Usually, in Windows Service, you do some activity in OnStart event. you can place a timer inside this OnStart and upon TimerTick(), you can request your webservice.
something like this:
class Program : ServiceBase
{
System.Timers.Timer timer;
static void Main(string[] args)
{
ServiceBase.Run(new Program());
}
public Program()
{
this.ServiceName = "My Service";
}
protected override void OnStart(string[] args)
{
base.OnStart(args);
InitializeTimer();
}
protected override void OnStop()
{
base.OnStop();
//TODO: clean up any variables and stop any threads
}
protected void InitializeTimer()
{
try
{
if (timer == null)
{
timer = new System.Timers.Timer();
timer.Enabled = true;
timer.AutoReset = true;
timer.Interval = 60000 * 1;
timer.Enabled = true;
timer.Elapsed += timer_Elapsed;
}
}
catch (Exception ex)
{
Utility.WriteLog("Exception InitialiseTimer : " + ex.Message.ToString());
}
finally
{
}
}
protected void timer_Elapsed(object source, System.Timers.ElapsedEventArgs e)
{
TimerTick();
timer.Interval = 60000 * Convert.ToDouble(ConfigurationManager.AppSettings["TimerInerval"]);
}
private void TimerTick()
{
try
{
DownloadFromFTPandValidate objDownLoadandValidate = new DownloadFromFTPandValidate();
objDownLoadandValidate.ProcessMain();
}
catch (Exception ex)
{
Utility.WriteLog("Exception InitialiseTimer : " + ex.Message.ToString());
}
}
}
Here, class DownloadFromFTPandValidate wraps the code to db activity. It shd give you an idea.
You will need a job scheduler for periodical task. I recommend you a good one. Check out this link: http://quartznet.sourceforge.net/
Why not using a trigger on your table which runs a stored procedure once data was modified, then use the xp_cmdshell to access the commandline form your stored procedure so you can run for example a batch file or whatever.
I'm trying to get Quartz.net working by embedding into my .Net MVC2 application. I know this is not ideal, but I'm just trying to get it up and running before moving it over to a service. I can't get my jobs to fire off, but I think I'm configured correctly. In my Global.asax.cs:
protected void Application_Start()
{
Quartz.IScheduler scheduler = BuildQuartzScheduler();
...
}
And the method, taken straight from the tutorial:
private IScheduler BuildQuartzScheduler()
{
// construct a scheduler factory
ISchedulerFactory schedFact = new StdSchedulerFactory();
// get a scheduler
IScheduler sched = schedFact.GetScheduler();
sched.Start();
// construct job info
JobDetail jobDetail = new JobDetail("myJob", null, typeof(QuartzController));
// fire every hour
Trigger trigger = TriggerUtils.MakeMinutelyTrigger();
// start on the next even hour
trigger.StartTimeUtc = TriggerUtils.GetEvenMinuteDate(DateTime.UtcNow);
trigger.Name = "myTrigger";
sched.ScheduleJob(jobDetail, trigger);
return sched;
}
And the "controller:"
public class QuartzController : IJob
{
public QuartzController() {
}
public void Execute(JobExecutionContext context) {
throw new NotImplementedException();
}
}
Nothing ever gets fired. What's going on? I'm sure there must be a simple syntax mistake, but it is driving me crazy!
If Application_Start looks like that, then I reckon your scheduler variable is likely to be garbage collected as soon as that method finishes executing.
I'd store a reference to the scheduler as a static variable in your HttpApplication class. This way, the reference hangs around for the duration of the process. A guess, but worth a shot.
I am new to Windows Workflow and trying to write a Long Running process.
I am also trying to limit how long this process can run for.
I am calling WorkflowInvoker.Invoke to trigger my Workflow passing it a small timespan for testing.
If I try this certain activities, this seems to work perfectly.
But If I use a CodeActivity, it seems to ignore my timeout entirely.
Why is this? And how do I cause my CodeActivity to timeout if it takes too long?
An example working with a Delay Activity:
(In this example the TimeOutException is thrown)
Activity wf = new Sequence()
{
Activities =
{
new Delay()
{
Duration = TimeSpan.FromSeconds(10)
},
}
};
try
{
WorkflowInvoker.Invoke(wf, TimeSpan.FromSeconds(5));
}
catch (TimeoutException ex)
{
Console.WriteLine(ex.Message);
}
An example trying to use a CodeActivity:
(In this example the TimeOutException is not thrown)
public class LongActivity : CodeActivity
{
protected override void Execute(CodeActivityContext context)
{
Thread.Sleep(TimeSpan.FromSeconds(10));
}
}
Activity wf = new Sequence()
{
Activities =
{
new LongActivity()
}
};
try
{
WorkflowInvoker.Invoke(wf, TimeSpan.FromSeconds(5));
}
catch (TimeoutException ex)
{
Console.WriteLine(ex.Message);
}
The workflow runtime can only take action when it is in charge and if your activity takes 10 seconds to execute, or sleep, the runtime can't do anything about it. It won't schedule any new activities though because there is no remaining time left and would throw a TimeoutException instead.
Normally when you have long running work you would use an asynchronous activity, either an AsyncCodeActivity or a NativeActivity with a bookmark so the runtime is in control and can abort the workflow.