AEM 6.3 : Creating Scheduler using OSGi R6 annotations - osgi

Question

I have written a scheduler using OSGi R6 annotations but it doesn't seem to run :
package com.aem.sites.interfaces;
import org.osgi.service.metatype.annotations.AttributeDefinition;
import org.osgi.service.metatype.annotations.AttributeType;
import org.osgi.service.metatype.annotations.ObjectClassDefinition;
#ObjectClassDefinition(name = "Scheduler Configuration for Weather", description = "Configuration file for Scheduler")
public #interface SchedulerConfiguration {
#AttributeDefinition(
name = "sample parameter",
description="Sample String parameter",
type = AttributeType.STRING
)
public String parameter() default "scheduler";
#AttributeDefinition(
name = "Concurrent",
description = "Schedule task concurrently",
type = AttributeType.BOOLEAN
)
boolean scheduler_concurrent() default true;
#AttributeDefinition(
name = "Expression",
description = "Cron-job expression. Default: run every minute.",
type = AttributeType.STRING
)
String scheduler_expression() default "0 * * * * ?";
}
and
package com.aem.sites.schedulers;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Activate;
import org.osgi.service.metatype.annotations.Designate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.aem.sites.interfaces.SchedulerConfiguration;
#Component(immediate = true,
configurationPid = "com.aem.sites.schedulers.WeatherServiceScheduler")
#Designate(ocd=SchedulerConfiguration.class)
public class WeatherServiceScheduler implements Runnable {
private final Logger logger = LoggerFactory.getLogger(this.getClass());
private String myParameter;
#Override
public void run() {
logger.info("*******************************************Sample OSGi Scheduler is now running", myParameter);
}
#Activate
public void activate(SchedulerConfiguration config) {
logger.info("*******************************************weather service scheduler"+ myParameter);
myParameter = config.parameter();
}
}
I am following this https://github.com/nateyolles/aem-osgi-annotation-demo/blob/master/core/src/main/java/com/nateyolles/aem/osgiannotationdemo/core/schedulers/SampleOsgiScheduledTask.java but looks like I am doing something wrong here. Not sure what though.
Thanks in advance

Answer 1

In your WeatherSchedulerService class, you are not registering it as a service. Instead of configurationPid, you can do like this service = Runnable.class.
The correct way to create a SlingScheduler using OSGi R6 annotations is as follows -
Create your OSGi configuration class
import org.osgi.service.metatype.annotations.AttributeDefinition;
import org.osgi.service.metatype.annotations.AttributeType;
import org.osgi.service.metatype.annotations.ObjectClassDefinition;
#ObjectClassDefinition(name = "Sling Scheduler Configuration", description = "This configuration is used to demonstrates a sling scheduler in action")
public #interface SchedulerConfiguration {
#AttributeDefinition(
name = "Scheduler name",
description = "Name of the scheduler",
type = AttributeType.STRING)
public String name() default "Custom Sling Scheduler";
#AttributeDefinition(
name = "Enabled",
description = "Flag to enable/disable a scheduler",
type = AttributeType.STRING)
public boolean enabled() default false;
#AttributeDefinition(
name = "Cron expression",
description = "Cron expression used by the scheduler",
type = AttributeType.STRING)
public String cronExpression() default "0 * * * * ?";
#AttributeDefinition(
name = "Custom parameter",
description = "Custom parameter to showcase the usage of a sling scheduler",
type = AttributeType.STRING)
public String customParameter();
}
Create your Scheduler class as a service. For creating an OSGi service using R6 annotations we use #Component(service=<your-interface>.class,...).
Thus, create a service as follows
import org.apache.sling.commons.scheduler.ScheduleOptions;
import org.apache.sling.commons.scheduler.Scheduler;
import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Deactivate;
import org.osgi.service.component.annotations.Modified;
import org.osgi.service.component.annotations.Reference;
import org.osgi.service.metatype.annotations.Designate;
import org.redquark.aem.learning.core.configurations.SchedulerConfiguration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
#Component(immediate = true, service = Runnable.class)
#Designate(ocd = SchedulerConfiguration.class)
public class CustomScheduler implements Runnable {
// Logger
private final Logger log = LoggerFactory.getLogger(this.getClass());
// Custom parameter that is to be read from the configuration
private String customParameter;
// Id of the scheduler based on its name
private int schedulerId;
// Scheduler instance injected
#Reference
private Scheduler scheduler;
/**
* Activate method to initialize stuff
*
* #param schedulerConfiguration
*/
#Activate
protected void activate(SchedulerConfiguration schedulerConfiguration) {
schedulerId = schedulerConfiguration.name().hashCode();
customParameter = schedulerConfiguration.customParameter();
}
/**
* Modifies the scheduler id on modification
*
* #param schedulerConfiguration
*/
#Modified
protected void modified(SchedulerConfiguration schedulerConfiguration) {
// Removing scheduler
removeScheduler();
// Updating the scheduler id
schedulerId = schedulerConfiguration.name().hashCode();
// Again adding the scheduler
addScheduler(schedulerConfiguration);
}
/**
* This method deactivates the scheduler and removes it
*
* #param schedulerConfiguration
*/
#Deactivate
protected void deactivate(SchedulerConfiguration schedulerConfiguration) {
// Removing the scheduler
removeScheduler();
}
/**
* This method removes the scheduler
*/
private void removeScheduler() {
log.info("Removing scheduler: {}", schedulerId);
// Unscheduling/removing the scheduler
scheduler.unschedule(String.valueOf(schedulerId));
}
/**
* This method adds the scheduler
*
* #param schedulerConfiguration
*/
private void addScheduler(SchedulerConfiguration schedulerConfiguration) {
// Check if the scheduler is enabled
if (schedulerConfiguration.enabled()) {
// Scheduler option takes the cron expression as a parameter and run accordingly
ScheduleOptions scheduleOptions = scheduler.EXPR(schedulerConfiguration.cronExpression());
// Adding some parameters
scheduleOptions.name(schedulerConfiguration.name());
scheduleOptions.canRunConcurrently(false);
// Scheduling the job
scheduler.schedule(this, scheduleOptions);
log.info("Scheduler added");
} else {
log.info("Scheduler is disabled");
}
}
/**
* Overridden run method to execute Job
*/
#Override
public void run() {
log.info("Custom Scheduler is now running using the passed custom paratmeter, customParameter {}",
customParameter);
}
In the activate() method, we are reading the required values. Then we are getting the schedulerId from the scheduler name.
The modified() method recalculates the schedulerId in case the OSGi configuration is modified.
In the addScheduler() method, we are registering the scheduler using the Scheduler API.
For more information and step by step execution, you can see my blog post as well - Day 13: Schedulers in AEM
I hope this helps. Happy coding!

Answer 2

There is no need for configurationPid in the class annotation, and also you are missing service=Runnable.class which should follow immediate=true, i.e. the class declaration should look like:
#Component(immediate = true, service=Runnable.class)
#Designate(ocd=SchedulerConfiguration.class)
public class WeatherServiceScheduler implements Runnable {