How to run Scheduled task after specific CommandLineRunner? - spring

Question

I do some initializations in a CommandLineRunner's run function and I want my Scheduled task to begin schedule after the initialization, how can I achive this?
For example, I have the CommandLineRunner:
#Component
public class MyCommandLineRunner implements CommandLineRunner {
#Override
public void run(String... args) throws Exception {
// Initializations
// ...
}
}
And the task scheduler:
public class SchedClass {
#Scheduled(fixedRate = ONE_SECOND)
public void sched() {
}
}
What can I do to make sched() runs after run() runs?

Answer 1

class MySchedulingConfigurer implements SchedulingConfigurer {
private ScheduledTaskRegistrar taskRegistrar;
private IntervalTask task;
public MySchedulingConfigurer(IntervalTask task) {
this.task = task;
}
#Override
public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
this.taskRegistrar = taskRegistrar;
}
public void resume() {
this.taskRegistrar.scheduleFixedRateTask(task);
}
}
#Configuration
class SchedulerConfiguration {
#Autowired
private MySchedulingConfigurer schedulingConfigurer;
#Bean
public MySchedulingConfigurer mySchedulingConfigurer() {
IntervalTask task = new IntervalTask(new MyTask(), 5000L);
return new MySchedulingConfigurer(task);
}
public static class MyTask implements Runnable {
#Override
public void run() {
System.out.println("===> task executed...");
}
}
#EventListener
public void startScheduler(ApplicationReadyEvent event){
schedulingConfigurer.resume();
}
}
#Component
class CacheLoadingRunner implements CommandLineRunner {
#Autowired
private MySchedulingConfigurer schedulingConfigurer;
#Override
public void run(String... args) throws Exception {
schedulingConfigurer.resume();
}
}

Answer 2

1) Add #EnableScheduling
#EnableScheduling
#SpringBootApplication
public class MyCommandLineRunner implements CommandLineRunner {
...
}
2) It makes no sense to denote Spring Boot application with #Component
UPDATED
It could be achieved manually. Provide a TaskScheduler
#Bean
public ThreadPoolTaskScheduler threadPoolTaskScheduler(){
ThreadPoolTaskScheduler threadPoolTaskScheduler = new ThreadPoolTaskScheduler();
threadPoolTaskScheduler.setPoolSize(5);
threadPoolTaskScheduler.setThreadNamePrefix("ThreadPoolTaskScheduler");
return threadPoolTaskScheduler;
}
Inject it into MyCommandLineRunner along with SchedClass and run
#Component
public class MyCommandLineRunner implements CommandLineRunner {
#Autowired
private ThreadPoolTaskScheduler taskScheduler;
#Autowired
private SchedClass schedBean;
#Override
public void run(String... args) throws Exception {
// ...
taskScheduler.scheduleWithFixedDelay(() -> schedBean.sched(), ONE_SECOND);
// ...
}
}