Good Day,
Is there any API for Java where I can "add" tasks like an OS? I have a ExecutorService that runs every 1 minute, and during this tick, I need it to send about 10 TCP messages to multiple sockets.
I currently have a function that goes sendMessage(string data,string ipAdd,int port)
I was wondering if there is an EASY API for me to simply go taskScheduler.addTask(sendMessage(..)) in a loop say 10 times for 10 different data, and I am guranteed for them to executed all simultaneously?
Thanks
yes there is. have a look at quartz scheduler.
its really not difficult to set-up:
// Grab the Scheduler instance from the Factory
Scheduler scheduler = StdSchedulerFactory.getDefaultScheduler();
// and start it off
scheduler.start();
// define the job and tie it to our HelloJob class
JobDetail job = newJob(HelloJob.class)
.withIdentity("job1", "group1")
.build();
// Trigger the job to run now, and then repeat every 40 seconds
Trigger trigger = newTrigger()
.withIdentity("trigger1", "group1")
.startNow()
.withSchedule(simpleSchedule()
.withIntervalInSeconds(40)
.repeatForever())
.build();
// Tell quartz to schedule the job using our trigger
scheduler.scheduleJob(job, trigger);
Related
I am working with Quartz scheduler and everything work perfect according to the requirement. But there one thing that I want to implement and i.e. I want my next execution of job will trigger on (currentFinishTime + intervalOfScheduler)
Example of job execution with 30 seconds of interval:
Job-1-First-Executed at 10-10-2020 18:30:05
Job-1-Second-Executed at 10-10-2020 18:30:35
Job-1-Third-Executed at 10-10-2020 18:31:05
So, here if the job takes 20 seconds to execute then next trigger will happen on 05+20+30 = 55. Instead of 10-10-2020 18:30:35, it will trigger at 10-10-2020 18:30:55 and same for other execution and so on...
Note: #DisallowConcurrentExecution and MyJobExecutor implements Job {public void execute(JobExecutionContext context){...}} are already implemented.
Please help me to solve my problem.
After a lots of research, I have implemented my own solution which suffice my requirement. The code is mentioned below:
if(isExecutionTimeIncluded) {
final TriggerBuilder triggerBuilder = context.getTrigger().getTriggerBuilder();
final Trigger newTrigger = triggerBuilder
.withSchedule(SimpleScheduleBuilder.simpleSchedule()
.withIntervalInSeconds(cpoPullJobData.getInterval())
.repeatForever())
.startAt(futureDate(interval/*eg.30*/, DateBuilder.IntervalUnit.SECOND);)
.build();
context.getScheduler().rescheduleJob(context.getTrigger().getKey(), newTrigger);
}
I'd like to develop a Java program that executes tasks registered in a database. The tasks have their own cron-like schedule, which is an object of CronExpression of Quartz Scheduler, and saved in the database after being serialized.
Tasks should be executed anytime according to its schedule, so I think the program should be daemonized, and may be able to be restarted or stopped outside the program (like an usual service beneath /etc/init.d/)
I'm studying the examples of Quartz
and saw the program running continuously even if there's no sleep and shutdown method. This seems nice to achieve my purpose, but I'm not sure if this way can generate a daemon process.
// TODO: Retrieve cron format from the database
Trigger trigger = org.quartz.TriggerBuilder.newTrigger()
.withIdentity("trigger1", "group1")
.withSchedule(cronSchedule("* * * ? * MON-FRI"))
.startNow()
.build();
try {
sched.scheduleJob(job, trigger);
sched.start();
// Thread.sleep(90L * 1000L);
// sched.shutdown(true);
} catch (SchedulerException e) {
...
My question is
What is the best way to build a cron job scheduler which runs continuously on a server?
Thank you in advance, and any opinions or questions would be appreciated.
What is the difference between pauseJob() and pauseTrigger() in quartz scheduler?
How can select one among them for use? now i want to pause/interept a specific job how can i do
my scheduler code is given bellow
JobDetail job = new JobDetail();
job.setName("pollerjob"+pollerId);
job.setJobClass(Pollersheduller.class);
job.getJobDataMap().put("socialMediaObj", socialMediaObj);
job.getJobDataMap().put("queue", queue);
//configure the scheduler time
SimpleTrigger trigger = new SimpleTrigger();
trigger.setName("pollerSocial"+pollerId);
trigger.setStartTime(new Date(System.currentTimeMillis() + 1000));
trigger.setRepeatCount(SimpleTrigger.REPEAT_INDEFINITELY);
trigger.setRepeatInterval(Long.parseLong(intervel));
//schedule it
Scheduler scheduler = null;
try {
scheduler = new StdSchedulerFactory().getScheduler();
scheduler.start();
scheduler.scheduleJob(job, trigger);
} catch (SchedulerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
As you have probably noticed, in Quartz a single job can be associated with multiple triggers. And if you look into Quartz sources, you will see that the pauseJob method simply retrieves all triggers associated with the specified job and pauses them, whereas the pauseTrigger method pauses only a particular trigger. So that is the main difference.
Please note that pausing a job in Quartz does not pause a currently running running job, it merely prevents the job from being run in the future!
If you want to interrupt a running job, then you can use the interruptJob method defined in the org.quartz.Interruptable interface the job must implement. If your job implements this interface, then it is entirely up to you to implement the interrupting logic. For example, you can set some sort of a flag when the interruptJob method is called and then you need to check the value of this flag in the job's execute method.
This is a silly question but I can't seem to find the answer online.
If it is 9:00 am and I schedule a job at 12:00 pm do I need to set my thread.sleep to 3 hours?
In other words, if I set my thread.sleep to just 5 minutes and follow it with a sched.shutdown(true) will my job still run at noon? Or will the scheduler have already shut down? I don't get the point of thread.sleep...Can someone please clarify?
EDIT added code:
try {
SchedulerFactory sf = new StdSchedulerFactory();
Scheduler sched = sf.getScheduler();
JobDetail job = newJob(HelloWorld.class)
.withIdentity("job0","group1")
.build();
CronTrigger trigger = newTrigger()
.withIdentity("trigger1", "group1")
.withSchedule(cronSchedule("0 0 12 ? 1-12 2-6"))
.build();
sched.scheduleJob(job,trigger);
sched.start();
Thread.sleep(300000L); //300000 milliseconds is 5 minutes
sched.shutdown(true);
} catch (SchedulerException ex) {
Logger.getLogger(IBTradeGui.class.getName()).log(Level.SEVERE, null, ex);
}
The sleep is only in the example code to demonstrate quartz. It is not something to do in production code.
It is best to start the scheduler when your application initializes and stop it when your application shuts down. Scheduling jobs is then handled in other parts of your program.
I am getting the "Based on configured schedule, the given trigger will never fire" error when scheduling my job. I have tried adding ".startNow()" to the trigger, but that didn't solve it. I don't understand what I have done wrong.
JobDetail jobDetail = newJob(DeploymentJob.class)
.withIdentity(scheduleName)
.usingJobData("uploadLocation", deployment.getUploadDir())
.build();
// Add the job to the Scheduler
scheduler.addJob(jobDetail, true);
// Create the trigger with cron expression
Trigger trigger = newTrigger()
.withIdentity(scheduleName)
.withSchedule(cronSchedule(cron))
.forJob(jobDetail)
.build();
// Tell quartz to schedule the job using our trigger
scheduler.scheduleJob(jobDetail, trigger); <--- Problem line.
scheduler.start();
Thanks in advance for the answers! Much appreciated!
Your setting time is beyond reach.Spring Quartz never execute the task which time is beyond reach.So change your setting time.