Spring : #Scheduled task triggered through the #Controller and Websocket - spring

Question

I have an #Scheduled task which send data to a client every sec throught a websocket.
My need is to start running my scheduled task only when the client ask for it.
Instead of, my task starts when my server starts. it's not the behavior i want.
currently, I have a bean of my scheduled task which is declared in my SchedulingConfigurer :
#Configuration
#EnableScheduling
public class SchedulingConfigurer implements org.springframework.scheduling.annotation.SchedulingConfigurer {
#Bean
public ThreadPoolTaskScheduler taskScheduler() {
return new ThreadPoolTaskScheduler();
}
#Bean
public ScheduledTask scheduledTask() {
return new ScheduledTask();
}
#Override
public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
taskRegistrar.setTaskScheduler(taskScheduler());
}
}
Here is my spring controller code :
#MessageMapping("/hello")
public void greeting() throws Exception {
//How do I start my scheduled task here ?
}
Maybe isn't possible to do that with #Scheduled annotation and i have to use the TaskScheduler interface ?

Answer 1

remove #Scheduled declaration from ScheduledTask class
implements Runnable interface instead of
#Component
//#Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
public class ScheduledTask implements Runnable {
private static final Logger log = LoggerFactory.getLogger(ScheduledTask.class);
private static final SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
public void doWork() {
printMessage();
// TODO real work
}
private void printMessage() {
log.info("time to work: {}", dateFormat.format(new Date()));
}
#Override
public void run() {
doWork();
}
}
schedule Your task in controller area like this
#Controller
public class ScheduledTaskController {
#Autowired
private TaskScheduler taskScheduler;
#Autowired
private ScheduledTask scheduledTask;
#RequestMapping(value = "/task/run", method = RequestMethod.GET)
public String runTask() {
// start to run task every 5 sec.
taskScheduler.schedule(scheduledTask, new CronTrigger("0/5 * * * * ?"));
// ok, redirect
return "redirect:/task";
}
}

Answer 2

#Schedule is the declarative way, so not the point you're trying to achieve here.
You could create a Bean using one of the TaskScheduler implementations, such as ThreadPoolTaskScheduler and inject that bean in your application.
It has all the necessary methods to dynamically schedule tasks.