Jobs

Strolch Job Handler

The StrolchJobsHandler manages background tasks and scheduled jobs within the Strolch Agent.

StrolchJob

A StrolchJob is a background task that can be executed periodically or on demand. It provides methods for:

• Scheduling: Define execution intervals using delays or CRON expressions.
• Execution: Logic is implemented in the execute method.
• Lifecycle: Jobs are registered with the StrolchJobsHandler.
• Privileges: Jobs run with specific privileges, typically as a system user or agent.

Implementing a Job

To create a new job, extend the StrolchJob class and implement the doExecute method.

public class MyJob extends StrolchJob {
    public MyJob(StrolchAgent agent, String id, String name, JobMode mode) {
        super(agent, id, name, mode);
    }

    @Override
    protected void doExecute(PrivilegeContext ctx) throws Exception {
        runAsAgent(tx -> {
            // Perform background work in a transaction
            tx.commitOnClose();
        });
    }
}

Job Modes

• JobMode.Manual: The job must be triggered manually.
• JobMode.Recurring: The job runs periodically based on a defined delay.
• JobMode.Cron: The job runs according to a CRON expression.

Scheduling a Job

Jobs can be scheduled programmatically or via configuration.

StrolchJobsHandler jobsHandler = agent.getComponent(StrolchJobsHandler.class);
MyJob job = jobsHandler.register(MyJob.class);
job.setDelay(1, TimeUnit.MINUTES, 5, TimeUnit.MINUTES);
job.schedule();

Model-based Configuration

Jobs can also be configured as Strolch Resource elements in the model. This allows for dynamic job registration and configuration without code changes.

A job resource must have the Type set to StrolchJob.

Example XML Configuration:

<Resource Id="expiredProductsJob" Name="Expired Products Job" Type="StrolchJob">
    <ParameterBag Id="parameters" Name="Parameters" Type="Parameters">
        <Parameter Id="className" Name="Class Name" Type="String" Value="com.example.MyJob"/>
        <Parameter Id="mode" Name="Job Mode" Type="String" Interpretation="Enumeration" Uom="JobMode" Value="Recurring"/>
        <Parameter Id="delay" Name="Delay" Type="Integer" Interpretation="TimeUnit" Uom="MINUTES" Value="30"/>
        <Parameter Id="initialDelay" Name="Initial Delay" Type="Integer" Interpretation="TimeUnit" Uom="SECONDS" Value="10"/>
    </ParameterBag>
</Resource>

Monitoring

The StrolchJobsHandler provides information about job status, last execution time, duration, and any exceptions that occurred.