Currently I have this :
@Scheduled(fixedRate=5000)
public void getSchedule(){
System.out.println("in scheduled job");
}
I could change this to use a reference to a property
@Scheduled(fixedRateString="${myRate}")
public void getSchedule(){
System.out.println("in scheduled job");
}
However I need to use a value obtained programmatically so the schedule can be changed without redeploying the app. What is the best way? I realize using annotations may not be possible...
Using a Trigger you can calculate the next execution time on the fly.
Something like this should do the trick (adapted from the Javadoc for @EnableScheduling):
@Configuration
@EnableScheduling
public class MyAppConfig implements SchedulingConfigurer {
@Autowired
Environment env;
@Bean
public MyBean myBean() {
return new MyBean();
}
@Bean(destroyMethod = "shutdown")
public Executor taskExecutor() {
return Executors.newScheduledThreadPool(100);
}
@Override
public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
taskRegistrar.setScheduler(taskExecutor());
taskRegistrar.addTriggerTask(
new Runnable() {
@Override public void run() {
myBean().getSchedule();
}
},
new Trigger() {
@Override public Date nextExecutionTime(TriggerContext triggerContext) {
Calendar nextExecutionTime = new GregorianCalendar();
Date lastActualExecutionTime = triggerContext.lastActualExecutionTime();
nextExecutionTime.setTime(lastActualExecutionTime != null ? lastActualExecutionTime : new Date());
nextExecutionTime.add(Calendar.MILLISECOND, env.getProperty("myRate", Integer.class)); //you can get the value from wherever you want
return nextExecutionTime.getTime();
}
}
);
}
}
You can also use Spring Expression Language (SpEL) for this.
Once this value is initialized, you won't be able to update this value.
@Scheduled(fixedRateString = "#{@applicationPropertyService.getApplicationProperty()}")
public void getSchedule(){
System.out.println("in scheduled job");
}
@Service
public class ApplicationPropertyService {
public String getApplicationProperty(){
//get your value here
return "5000";
}
}
To create and manage multiple dynamically scheduled tasks,
Scheduler configuration and bean:
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
@Configuration
@EnableScheduling
public class SchedulingConfigs implements SchedulingConfigurer {
@Override
public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
taskRegistrar.addTriggerTask(new Runnable() {
@Override
public void run() {
// Do not put @Scheduled annotation above this method, we don't need it anymore.
System.out.println("Running Scheduler..." + Calendar.getInstance().getTime());
}
}, new Trigger() {
@Override
public Date nextExecutionTime(TriggerContext triggerContext) {
Calendar nextExecutionTime = new GregorianCalendar();
Date lastActualExecutionTime = triggerContext.lastActualExecutionTime();
nextExecutionTime.setTime(lastActualExecutionTime != null ? lastActualExecutionTime : new Date());
nextExecutionTime.add(Calendar.MILLISECOND, getNewExecutionTime());
return nextExecutionTime.getTime();
}
});
}
private int getNewExecutionTime() {
//Load Your execution time from database or property file
return 1000;
}
@Bean
public TaskScheduler poolScheduler() {
ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
scheduler.setThreadNamePrefix("ThreadPoolTaskScheduler");
scheduler.setPoolSize(1);
scheduler.initialize();
return scheduler;
}
}
Scheduler service code:
package io.loadium.resource.service;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.context.event.EventListener;
import org.springframework.scheduling.TaskScheduler;
import org.springframework.stereotype.Service;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ScheduledFuture;
@Service
public class ScheduleTaskService {
// Task Scheduler
TaskScheduler scheduler;
// A map for keeping scheduled tasks
Map<Integer, ScheduledFuture<?>> jobsMap = new HashMap<>();
public ScheduleTaskService(TaskScheduler scheduler) {
this.scheduler = scheduler;
}
// Schedule Task to be executed every night at 00 or 12 am
public void addTaskToScheduler(int id, Runnable task, Date runningDate) {
ScheduledFuture<?> scheduledTask = scheduler.schedule(task, runningDate);
jobsMap.put(id, scheduledTask);
}
// Remove scheduled task
public void removeTaskFromScheduler(int id) {
ScheduledFuture<?> scheduledTask = jobsMap.get(id);
if (scheduledTask != null) {
scheduledTask.cancel(true);
jobsMap.put(id, null);
}
}
// A context refresh event listener
@EventListener({ContextRefreshedEvent.class})
void contextRefreshedEvent() {
// Get all tasks from DB and reschedule them in case of context restarted
}
}
Sample usage:
// Add a new task with runtime after 10 seconds
scheduleTaskService.addTaskToScheduler(1, () -> System.out.println("my task is running -> 1"), , Date.from(LocalDateTime.now().plusSeconds(10).atZone(ZoneId.systemDefault()).toInstant()));
// Remove scheduled task
scheduleTaskService.removeTaskFromScheduler(1);
Also you can use this simple approach:
private int refreshTickNumber = 10;
private int tickNumber = 0;
@Scheduled(fixedDelayString = "${some.rate}")
public void nextStep() {
if (tickNumber < refreshTickNumber) {
tickNumber++;
return;
}
else {
tickNumber = 0;
}
// some code
}
refreshTickNumber is fully configurable at runtime and can be used with @Value annotation.
you can manage restarting scheduling using TaskScheduler and ScheduledFuture :
@Configuration
@EnableScheduling
@Component
public class CronConfig implements SchedulingConfigurer , SchedulerObjectInterface{
@Autowired
private ScheduledFuture<?> future;
@Autowired
private TaskScheduler scheduler;
@Bean
public SchedulerController schedulerBean() {
return new SchedulerController();
}
@Bean(destroyMethod = "shutdown")
public Executor taskExecutor() {
return Executors.newScheduledThreadPool(100);
}
@Override
public void start() {
future = scheduler.schedule(new Runnable() {
@Override
public void run() {
//System.out.println(JOB + " Hello World! " + new Date());
schedulerBean().schedulerJob();
}
}, new Trigger() {
@Override public Date nextExecutionTime(TriggerContext triggerContext) {
Calendar nextExecutionTime = new GregorianCalendar();
Date lastActualExecutionTime = triggerContext.lastActualExecutionTime();
nextExecutionTime.setTime(convertExpresssiontoDate());//you can get the value from wherever you want
return nextExecutionTime.getTime();
}
});
}
@Override
public void stop() {
future.cancel(true);
}
@Override
public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
// TODO Auto-generated method stub
start();
}
}
interface for start stop :
public interface SchedulerObjectInterface {
void start();
void stop();
}
now you can stop and start again (restarting) Scheduling using @Autowired SchedulerObjectInterface
Simple Spring Boot example restricted to second, minute, and hourly intervals. Intent of this example is to demonstrate conditional handling of two properties, TimeUnit and interval.
Properties:
snapshot.time-unit=SECONDS
snapshot.interval=5
Scheduled method:
@Scheduled(cron = "*/1 * * * * *")
protected void customSnapshotScheduler()
{
LocalDateTime now = LocalDateTime.now();
TimeUnit timeUnit = TimeUnit.valueOf(snapshotProperties.getSnapshot().getTimeUnit());
int interval = snapshotProperties.getSnapshot().getInterval();
if (TimeUnit.SECONDS == timeUnit
&& now.getSecond() % interval == 0)
{
this.camService.writeSnapshot(webcam.getImage());
}
if (TimeUnit.MINUTES == timeUnit
&& now.getMinute() % interval == 0)
{
this.camService.writeSnapshot(webcam.getImage());
}
if (TimeUnit.HOURS == timeUnit
&& now.getHour() % interval == 0)
{
this.camService.writeSnapshot(webcam.getImage());
}
}
See How we are calling "#{@getIntervalTime}" in MySchedularService Class and taking the time interval for next scheduled call from @Bean annotate class
package com;
import java.util.Calendar;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.scheduling.annotation.EnableScheduling;
@SpringBootApplication
@EnableScheduling
public class SbootSchedularApplication {
public static void main(String[] args) {
SpringApplication.run(SbootSchedularApplication.class, args);
}
@Value("${schedular3Timing}")
String schedular3Timing;
@Bean
public String getIntervalTime()
{
long startSchedulerAfterMiliSec = setSchedule(schedular3Timing);
return ""+startSchedulerAfterMiliSec;
}
public long setSchedule(String key)
{
int hour = Integer.parseInt(key.substring(0, key.indexOf(":")));
int min = Integer.parseInt(key.substring(key.indexOf(":") + 1));
Calendar schedulerCal = Calendar.getInstance();
schedulerCal.set(Calendar.HOUR, hour);
schedulerCal.set(Calendar.MINUTE, min);
schedulerCal.set(Calendar.SECOND, 0);
Calendar localCal = Calendar.getInstance();
Long currentTimeInMilliSec = localCal.getTime().getTime();
String currentDayTime = localCal.getTime().toString();
if (schedulerCal.getTime().getTime() < currentTimeInMilliSec) { // Means calculating time reference from time 00:00, if current time is 1000 mili-sec and scheduled time is 800 mili-sec -> then that time is already happened, so better add one more day in that same timing.
schedulerCal.add(Calendar.DATE, 1); // add 1 day more in the Schedular, if scheduled-MiliSec is less than the current-MiliSec.
}
long scheduledTimeInMilliSec = schedulerCal.getTime().getTime();
String scheduledTime = schedulerCal.getTime().toString();
System.out.println("** Scheduled start time for the task : " + scheduledTime + " *** " + scheduledTimeInMilliSec);
System.out.println("** Current time of the day : " + currentDayTime + " *** " + currentTimeInMilliSec);
long startScheduler = scheduledTimeInMilliSec - currentTimeInMilliSec; // eg: scheduledTime(5pm) - currentTime(3pm) = (2hr)startSchedulerAfter
return startScheduler;
}
}
package com.service;
import java.util.Date;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;
@Service
public class MySchedularService {
private static final Logger logger = LoggerFactory.getLogger(MySchedularService.class);
// @Scheduled(fixedRate = 2000, initialDelay = 5000L)
@Scheduled(fixedRateString = "${schedular1.fixedRateInMS}", initialDelay = 1000L)
public void job() {
logger.info("Job1 Run Time : " + new Date());
}
// @Scheduled(fixedRateString = "${schedular2.fixedRateInMS}", initialDelay = 5000L)
// public void job2() {
// logger.info("Job2 Run Time : " + new Date());
// }
@Scheduled(fixedRate = 10000 , initialDelayString = "#{@getIntervalTime}") // we can change the fixedRate = 86400000L miliseconds (i.e, one day interval)
public void job3() {
logger.info("**Job2 Run Time : " + new Date());
}
}
spring.task.scheduling.pool.size=10
schedular1.fixedRateInMS=3000
schedular2.fixedRateInMS=10000
schedular3Timing=01:07
i created dynamic tasks using ThreadPoolTaskScheduler from org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler
and scheduleWithFixedDelay method. i also added a redisson lock inorder to prevent duplicated jobs in distributed environment here is my code:
public class TaskRunnerService {
private final ThreadPoolTaskScheduler taskScheduler;
private final RedissonClient redissonClient;
public TaskRunnerService(ThreadPoolTaskScheduler taskScheduler, RedissonClient redissonClient) {
this.taskScheduler = taskScheduler;
this.redissonClient = redissonClient;
}
@PostConstruct
public void runTasks() {
List<TaskDTO> taskDTOS = TaskHolder.createTasks();
for (TaskDTO taskDTO : taskDTOS) {
RLock lock = this.redissonClient.getFairLock("LoadAndRunScheduleService-" + taskDTO.getId());
if (lock.tryLock()) {
try {
this.taskScheduler.scheduleWithFixedDelay(() -> {
System.out.println(" running task " + taskDTO.getId() + " with delay " + taskDTO.getDelay() + " at " + new Date());
}, taskDTO.getDelay() * 1000L);
}finally {
lock.unlock();
}
}
}
}
}
i created a TaskDTO class to be able to get delay at runtime:
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
@AllArgsConstructor
@NoArgsConstructor
@Getter
@Setter
public class TaskDTO {
private int id;
private int delay;
}
and configuration class is:
@Configuration
public class AppConfig {
@Bean
ThreadPoolTaskScheduler taskScheduler(){
ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
scheduler.setThreadNamePrefix("ThreadPoolTaskScheduler");
scheduler.setPoolSize(2);
scheduler.initialize();
return scheduler;
}
}
