org.flowable.engine.delegate

Interface FutureJavaDelegate<Output>

Type Parameters:

Output - the output of the execution

All Known Subinterfaces:

FlowableFutureJavaDelegate<Input,Output>, MapBasedFlowableFutureJavaDelegate

All Known Implementing Classes:

DefaultBpmnHttpActivityDelegate

public interface FutureJavaDelegate<Output>

Convenience class that should be used when a Java delegation in a BPMN 2.0 process is required (for example, to call custom business logic). When this interface is implemented then the execution of the logic can happen on a different thread then the process execution.

This class can be used only for service tasks.

This class does not allow to influence the control flow. It follows the default BPMN 2.0 behavior of taking every outgoing sequence flow (which has a condition that evaluates to true if there is a condition defined) If you are in need of influencing the flow in your process, use the class 'org.flowable.engine.impl.pvm.delegate.ActivityBehavior' instead.

This interface allows fine grained control on how the future should be created. It gives access to the AsyncTaskInvoker which can delegate execution to a shared task executor. However, it doesn't have to be used. In case you don't need custom task executor the FlowableFutureJavaDelegate can be used.

Author:

Filip Hrisafov

See Also:

FlowableFutureJavaDelegate, MapBasedFlowableFutureJavaDelegate

Method Summary

Modifier and Type	Method and Description
void	afterExecution(DelegateExecution execution, Output executionData) Method invoked with the result from execute(DelegateExecution, AsyncTaskInvoker).
CompletableFuture<Output>	execute(DelegateExecution execution, AsyncTaskInvoker taskInvoker) Perform the execution of the delegate, potentially on another thread.

Method Detail

execute

CompletableFuture<Output> execute(DelegateExecution execution,
                                  AsyncTaskInvoker taskInvoker)

Perform the execution of the delegate, potentially on another thread. The result of the future is passed in the afterExecution(DelegateExecution, Object) in order to store the data on the execution on the same thread as the caller of this method. IMPORTANT: the execution should only be used to read data before creating the future. The execution should not be used in the task that will be executed on a new thread.

The AsyncTaskInvoker is in order to schedule an execution on a different thread. However, it is also possible to use a different scheduler, or return a future not created by the given taskInvoker.

Parameters:

execution - the execution that can be used to extract data

taskInvoker - the task invoker that can be used to execute expensive operation on another thread

Returns:

the output data of the execution

afterExecution

void afterExecution(DelegateExecution execution,
                    Output executionData)

Method invoked with the result from execute(DelegateExecution, AsyncTaskInvoker). This should be used to set data on the DelegateExecution. This is on the same thread as execute(DelegateExecution, AsyncTaskInvoker) and participates in the process transaction.

Parameters:

execution - the execution to which data can be set

executionData - the execution data