DZone
Java Zone
Thanks for visiting DZone today,
Edit Profile
  • Manage Email Subscriptions
  • How to Post to DZone
  • Article Submission Guidelines
Sign Out View Profile
  • Post an Article
  • Manage My Drafts
Over 2 million developers have joined DZone.
Log In / Join
  • Refcardz
  • Trend Reports
  • Webinars
  • Zones
  • |
    • Agile
    • AI
    • Big Data
    • Cloud
    • Database
    • DevOps
    • Integration
    • IoT
    • Java
    • Microservices
    • Open Source
    • Performance
    • Security
    • Web Dev
DZone > Java Zone > Lightweight Workflow Execution Using Dexecutor

Lightweight Workflow Execution Using Dexecutor

Organizing your tasks in a manageable way can be difficult and unwieldly. Add in something like Dexecutor, and your life gets a whole lot easier.

Mohammad Nadeem user avatar by
Mohammad Nadeem
·
Nov. 10, 16 · Java Zone · Tutorial
Like (6)
Save
Tweet
35.84K Views

Join the DZone community and get the full member experience.

Join For Free

Dexecutor can be used very easily for workflow like cases as depicted in the following diagram.

dexecutor-workflow-example

Dexecutor instance is created using DexecutorConfig, which in turn requires ExecutionEngine and TaskProvider, Default Implementation of ExecutionEngine uses ExecutorService, so lets create a Dexecutor Instance first (source code can be found here):

private static ExecutorService buildExecutor() {
   ExecutorService executorService = Executors.newFixedThreadPool(ThreadPoolUtil.ioIntesivePoolSize());
   return executorService;
 }
private Dexecutor<String, Boolean> buildDexecutor(final ExecutorService executorService) {
   DexecutorConfig<String, Boolean> config = new DexecutorConfig<>(executorService, new WorkFlowTaskProvider());
   return new DefaultDexecutor<>(config);
 }

TaskProvider comes into action, when it is the time to execute the task, for this example we will have simple implementation WorkFlowTaskProvider

public class WorkFlowTaskProvider implements TaskProvider<String, Boolean> {

    private final Map<String, Task<String, Boolean>> tasks = new HashMap<String, Task<String, Boolean>>() {

        private static final long serialVersionUID = 1L;
        {
            put(TaskOne.NAME, new TaskOne());
            put(TaskTwo.NAME, new TaskTwo());
            put(TaskThree.NAME, new TaskThree());
            put(TaskFour.NAME, new TaskFour());
            put(TaskFive.NAME, new TaskFive());
            put(TaskSix.NAME, new TaskSix());
            put(TaskSeven.NAME, new TaskSeven());
        }    
    };

    @Override
    public Task<String, Boolean> provideTask(final String id) {
        return this.tasks.get(id);
    }
}

For simplicity, we have implemented Task for each of the tasks (1..7), those can be found here, Most of the task implementations are same except for TaskTwo (if task 2 result is TRUE then tasks 3 and 4 would be executed otherwise task 5 would be executed) and TaskFive (If task 5 is executed (not skipped) then task task 6 would be executed).

dexecutor-task

TaskFive (TaskThree, TaskFour and TaskSix) overrides shouldExecute() method, to signal if the task should be executed or skipped.

dexecutor-skipping-task-execution

Next step is to build the graph:

dexecutor-workflow-graph-building

If WorkFlowApplication is executed, the following output can be observed.

Output if TaskTwo Is False

Executing TaskOne , result : true
Executing TaskTwo , result : false
Executing TaskFive , result : true
Executing TaskSix , result : true
Executing TaskSeven , result : true

Output if TaskTwo Is True

Executing TaskOne , result : true
Executing TaskTwo , result : true
Executing TaskFour , result : true
Executing TaskThree , result : true
Executing TaskSeven , result : true


Task (computing) workflow Execution (computing)

Published at DZone with permission of Mohammad Nadeem, DZone MVB. See the original article here.

Opinions expressed by DZone contributors are their own.

Popular on DZone

  • Purpose-Driven Microservice Design
  • Top 7 Features in Jakarta EE 10 Release
  • Open Source Monitoring and Metrics Landscape
  • Migrating Legacy Applications and Services to Low Code

Comments

Java Partner Resources

X

ABOUT US

  • About DZone
  • Send feedback
  • Careers
  • Sitemap

ADVERTISE

  • Advertise with DZone

CONTRIBUTE ON DZONE

  • Article Submission Guidelines
  • MVB Program
  • Become a Contributor
  • Visit the Writers' Zone

LEGAL

  • Terms of Service
  • Privacy Policy

CONTACT US

  • 600 Park Offices Drive
  • Suite 300
  • Durham, NC 27709
  • support@dzone.com
  • +1 (919) 678-0300

Let's be friends:

DZone.com is powered by 

AnswerHub logo