Command Executor.

(1)
@SagaExecutor(
        executeFor = "delivery-service", (2)
        liveCheck = true, (3)
        value = "DispatchOrderExecutor" (4)
)
public class DispatchOrderExecutor implements CommandExecutor<PlaceOrderAggregator> { (5)

    (6)
    @Override
    public ProcessStepManager<PlaceOrderAggregator> doProcess(
            ProcessStack processStack, (7)
            PlaceOrderAggregator aggregator, (8)
            ProcessStepManagerUtil<PlaceOrderAggregator> stepManager (9)
    ) throws RetryableExecutorException, NonRetryableExecutorException {
        //execute the service and check the conndtion.
        ...
        //return or throw (10)
    }

    @RevertBefore(startFrom = DispatchRevertNotifierExecutor.class) (11)
    @RevertAfter(startFrom = DispatchRevertCompleteLogExecutor.class) (12)
    @Override
    public void doRevert(
            ProcessStack processStack,(13)
            NonRetryableExecutorException nonRetryableExecutorException,(14)
            PlaceOrderAggregator aggregator, (15)
            RevertHintStore revertHintStore (16)
    ) throws RetryableExecutorException {
        //call the atomic process that you want to as the Compensating,
        ...
    }
}
1 @SagaExecutor: annotate your query executor with @org.stacksaga.annotation.SagaExecutor annotation. The annotation provides the spring bean capabilities and also another metadata for the StackSaga framework.
2 executeFor: The name of the service that particular executor is going to be connected. it can be a service name of another service. if the service is spring boot service, make sure to keep the application name as its. because it will be helpful for the retry process.
3 liveCheck: When the retry process is executed, liveCheck is considered by the engine. if the target service is a spring boot service or registered service with the service registry, the availability is checked before executing the retry by the StackSaga engine.
4 value: The bean name of the executor. The executor is identified with this value by StackSaga engine. after configuring the bean name, it cannot be changed at all. if you want to the class package, it does not matter without changing the configured name.
5 CommandExecutor<T> IF the executor is command one, The executor should be implemented by org.stacksaga.executor.CommandExecutor<T>. T should be the target Aggregator class for the domain.
6 Override the doProcess() method and put your execution code block that should be executed when the executor is executed by the StackSaga engine.
7 ProcessStack Object provides all the executed execution until the process so far. It will help for gen an idea about the execution history. And also you can get the decision of the execution base on the execution history.
8 PlaceOrderAggregator: The current aggregator state.
9 ProcessStepManagerUtil<T>: This object provides the methods for giving the navigation to the engine regarding the next step. it can be another executor (command or query) or a process completion.
10 Inside the method scope, you can provide the execution that should be executed when the StackSaga engine executes. And finally you can navigate to the next step by using the ProcessStepManagerUtil object.
11 @RevertBefore: If the executor has any revert-before-executors, you can mention that executor class with @RevertBefore annotation. According to the example, the revert before execution will be started from DispatchRevertNotifierExecutor.
12 @RevertAfter: If the executor has any revert-after-executors, you can mention that executor class with @RevertAfter annotation. According to the example, the revert after execution will be started from DispatchRevertCompleteLogExecutor.
13 ProcessStack The final process stack that was when the final execution was executed.
14 NonRetryableExecutorException The exception that caused the transition process stopping to forward.
15 PlaceOrderAggregator The final aggregator state when the NonRetryableExecutorException is thrown.
16 RevertHintStore If you want to add some data to the backward process, you can use the RevertHintStore to put the data.