Schedules - Java SDK

This page shows how to do the following:

• How to Schedule a Workflow
  • How to create a Schedule in Java
  • How to backfill a Schedule in Java
  • How to delete a Schedule in Java
  • How to describe a Schedule in Java
  • How to list a Schedule in Java
  • How to pause a Schedule in Java
  • How to trigger a Schedule in Java
  • How to update a Schedule in Java
• How to set a Cron Schedule in Java
• Start Delay

How to Schedule a Workflow

Scheduling Workflows is a crucial aspect of any automation process, especially when dealing with time-sensitive tasks. By scheduling a Workflow, you can automate repetitive tasks, reduce the need for manual intervention, and ensure timely execution of your business processes

Use any of the following action to help Schedule a Workflow Execution and take control over your automation process.

How to create a Schedule in Java

The create action enables you to create a new Schedule. When you create a new Schedule, a unique Schedule ID is generated, which you can use to reference the Schedule in other Schedule commands.

To create a Scheduled Workflow Execution in Java, use the createSchedule() method on the ScheduleClient. Schedules must be initialized with a Schedule ID,

Schedule schedule =
    Schedule.newBuilder()
        .setAction(
            ScheduleActionStartWorkflow.newBuilder()
                .setWorkflowType(HelloSchedules.GreetingWorkflow.class)
                .setArguments("World")
                .setOptions(
                    WorkflowOptions.newBuilder()
                        .setWorkflowId("WorkflowId")
                        .setTaskQueue("TaskQueue")
                        .build())
                .build())
        .setSpec(ScheduleSpec.newBuilder().build())
        .build();

// Create a schedule on the server
ScheduleHandle handle =
    scheduleClient.createSchedule("ScheduleId", schedule, ScheduleOptions.newBuilder().build());

Schedule Auto-Deletion

Once a Schedule has completed creating all its Workflow Executions, the Temporal Service deletes it since it won’t fire again. The Temporal Service doesn't guarantee when this removal will happen.

How to backfill a Schedule in Java

The backfill action executes Actions ahead of their specified time range. This command is useful when you need to execute a missed or delayed Action, or when you want to test the Workflow before its scheduled time.

To Backfill a Scheduled Workflow Execution in Java, use the backfill() method on the ScheduleHandle.

ScheduleHandle handle = client.getHandle("schedule-id")

Instant now = Instant.now();
handle.backfill(
    Arrays.asList(
        new ScheduleBackfill(now.minusMillis(5500), now.minusMillis(2500)),
        new ScheduleBackfill(now.minusMillis(2500), now)));

How to delete a Schedule in Java

The delete action enables you to delete a Schedule. When you delete a Schedule, it does not affect any Workflows that were started by the Schedule.

To delete a Scheduled Workflow Execution in Java, use the delete() method on the Schedule Handle.

ScheduleHandle handle = client.getHandle("schedule-id")
handle.delete();

How to describe a Schedule in Java

The describe action shows the current Schedule configuration, including information about past, current, and future Workflow Runs. This command is helpful when you want to get a detailed view of the Schedule and its associated Workflow Runs.

To describe a Scheduled Workflow Execution in Java, use the describe() method on the ScheduleHandle.

ScheduleHandle handle = client.getHandle("schedule-id")
ScheduleDescription description = handle.describe();

How to list a Schedule in Java

The list action lists all the available Schedules. This command is useful when you want to view a list of all the Schedules and their respective Schedule IDs.

To list all schedules, use the listSchedules() asynchronous method on the ScheduleClient. If a schedule is added or deleted, it may not be available in the list immediately.

Stream<ScheduleListDescription> scheduleStream = client.listSchedules();

How to pause a Schedule in Java

The pause action enables you to pause and unpause a Schedule. When you pause a Schedule, all the future Workflow Runs associated with the Schedule are temporarily stopped. This command is useful when you want to temporarily halt a Workflow due to maintenance or any other reason.

To pause a Scheduled Workflow Execution in Java, use the pause() method on the ScheduleHandle. You can pass a note to the pause() method to provide a reason for pausing the schedule.

ScheduleHandle handle = client.getHandle("schedule-id")
handle.pause("Pausing the schedule for now");

How to trigger a Schedule in Java

The trigger action triggers an immediate action with a given Schedule. By default, this action is subject to the Overlap Policy of the Schedule. This command is helpful when you want to execute a Workflow outside of its scheduled time.

To trigger a Scheduled Workflow Execution in Java, use the trigger() method on the ScheduleHandle.

ScheduleHandle handle = client.getHandle("schedule-id")
handle.trigger();

How to update a Schedule in Java

The update action enables you to update an existing Schedule. This command is useful when you need to modify the Schedule's configuration, such as changing the start time, end time, or interval.

Create a function that takes ScheduleUpdateInput and returns ScheduleUpdate. To update a Schedule, use a callback to build the update from the description. The following example updates the Schedule to set a limited number of actions.

ScheduleHandle handle = client.getHandle("schedule-id")
handle.update(
    (ScheduleUpdateInput input) -> {
      Schedule.Builder builder = Schedule.newBuilder(input.getDescription().getSchedule());
      // Make the schedule paused to demonstrate how to unpause a schedule
      builder.setState(
          ScheduleState.newBuilder()
              .setLimitedAction(true)
              .setRemainingActions(10)
              .build());
      return new ScheduleUpdate(builder.build());
    });

How to set a Cron Schedule in Java

Cron support is not recommended

We recommend using Schedules instead of Cron Jobs. Schedules were built to provide a better developer experience, including more configuration options and the ability to update or pause running Schedules.

A Temporal Cron Job is the series of Workflow Executions that occur when a Cron Schedule is provided in the call to spawn a Workflow Execution.

A Cron Schedule is provided as an option when the call to spawn a Workflow Execution is made.

Set the Cron Schedule with the WorkflowStub instance in the Client code using WorkflowOptions.Builder.setCronSchedule.

Setting setCronSchedule changes the Workflow Execution into a Temporal Cron Job. The default timezone for a Cron is UTC.

• Type: String
• Default: None

//create Workflow stub for YourWorkflowInterface
YourWorkflowInterface workflow1 =
    YourWorker.yourclient.newWorkflowStub(
        YourWorkflowInterface.class,
        WorkflowOptions.newBuilder()
                .setWorkflowId("YourWF")
                .setTaskQueue(YourWorker.TASK_QUEUE)
                // Set Cron Schedule
                .setCronSchedule("* * * * *")
                .build());

For more details, see the Cron Sample

Start Delay

How to delay the start of a Workflow Execution using Start Delay with the Temporal Java SDK.

Use the StartDelay to schedule a Workflow Execution at a specific one-time future point rather than on a recurring schedule.

Create an instance of WorkflowStub in the Client code and set StartDelay using setStartDelay.

//create Workflow stub for YourWorkflowInterface
YourWorkflowInterface workflow1 =
    WorkerGreet.greetclient.newWorkflowStub(
        GreetWorkflowInterface.class,
        WorkflowOptions.newBuilder()
                .setWorkflowId("YourWorkflow")
                .setTaskQueue(WorkerGreet.TASK_QUEUE)
                // Start the workflow in 12 hours
                .setStartDelay(Duration.ofHours(12))
                .build());