How to: Author and manage Dapr Jobs in the Java SDK

How to get up and running with Jobs using the Dapr Java SDK

As part of this demonstration we will schedule a Dapr Job. The scheduled job will trigger an endpoint registered in the same app. With the provided jobs example, you will:

This example uses the default configuration from dapr init in self-hosted mode.

Prerequisites

Set up the environment

Clone the Java SDK repo and navigate into it.

git clone https://github.com/dapr/java-sdk.git cd java-sdk

Run the following command to install the requirements for running the jobs example with the Dapr Java SDK.

mvn clean install -DskipTests

From the Java SDK root directory, navigate to the examples’ directory.

cd examples

Run the Dapr sidecar.

dapr run --app-id jobsapp --dapr-grpc-port 51439 --dapr-http-port 3500 --app-port 8080

Now, Dapr is listening for HTTP requests at http://localhost:3500 and internal Jobs gRPC requests at http://localhost:51439.

Schedule and Get a job

In the DemoJobsClient there are steps to schedule a job. Calling scheduleJob using the DaprPreviewClient will schedule a job with the Dapr Runtime.

public class DemoJobsClient {   /**  * The main method of this app to schedule and get jobs.  */  public static void main(String[] args) throws Exception {  try (DaprPreviewClient client = new DaprClientBuilder().withPropertyOverrides(overrides).buildPreviewClient()) {   // Schedule a job.  System.out.println("**** Scheduling a Job with name dapr-jobs-1 *****");  ScheduleJobRequest scheduleJobRequest = new ScheduleJobRequest("dapr-job-1",  JobSchedule.fromString("* * * * * *")).setData("Hello World!".getBytes());  client.scheduleJob(scheduleJobRequest).block();   System.out.println("**** Scheduling job dapr-jobs-1 completed *****");  }  } }

Call getJob to retrieve the job details that were previously created and scheduled.

client.getJob(new GetJobRequest("dapr-job-1")).block()

Run the DemoJobsClient with the following command.

java -jar target/dapr-java-sdk-examples-exec.jar io.dapr.examples.jobs.DemoJobsClient

Sample output

**** Scheduling a Job with name dapr-jobs-1 ***** **** Scheduling job dapr-jobs-1 completed ***** **** Retrieving a Job with name dapr-jobs-1 *****

Set up an endpoint to be invoked when the job is triggered

The DemoJobsSpringApplication class starts a Spring Boot application that registers the endpoints specified in the JobsController This endpoint acts like a callback for the scheduled job requests.

@RestController public class JobsController {   /**  * Handles jobs callback from Dapr.  *  * @param jobName name of the job.  * @param payload data from the job if payload exists.  * @return Empty Mono.  */  @PostMapping("/job/{jobName}")  public Mono<Void> handleJob(@PathVariable("jobName") String jobName,  @RequestBody(required = false) byte[] payload) {  System.out.println("Job Name: " + jobName);  System.out.println("Job Payload: " + new String(payload));   return Mono.empty();  } }

Parameters:

  • jobName: The name of the triggered job.
  • payload: Optional payload data associated with the job (as a byte array).

Run the Spring Boot application with the following command.

java -jar target/dapr-java-sdk-examples-exec.jar io.dapr.examples.jobs.DemoJobsSpringApplication

Sample output

Job Name: dapr-job-1 Job Payload: Hello World!

Delete a scheduled job

public class DemoJobsClient {   /**  * The main method of this app deletes a job that was previously scheduled.  */  public static void main(String[] args) throws Exception {  try (DaprPreviewClient client = new DaprClientBuilder().buildPreviewClient()) {   // Delete a job.  System.out.println("**** Delete a Job with name dapr-jobs-1 *****");  client.deleteJob(new DeleteJobRequest("dapr-job-1")).block();  }  } }

Next steps