Camunda Java Integration - external service task implementation.

In this repository you can find some sample external worker implementation using camunda-external-task-client, this spring-boot application act as a client by subscribing to set of topics (Camunda's external service tasks), this client continuously poll to camunda with backoff strategy to process active instances.

Camunda Rest API - FetchAndLock backoff strategy based integration.

Java version

• Default build/runtime: Java 21
• Optional fallback: Java 17 via Maven profile java17

External service-task example (Start order processing workflow)

1. Start camunda instance in your local using docker image

       docker pull camunda/camunda-bpm-platform:latest
       docker run -d --name camunda -p 8080:8080 camunda/camunda-bpm-platform:latest

2. Install Camunda Modeler Camunda Modeler

3. Deploy BPMN file using modeler - resource/order-processing.bpmn

4. Deploy the process definition using Camunda Rest API

       curl -X POST http://localhost:8080/engine-rest/deployment/create \
         --user demo:demo \
         -H "Content-Type: multipart/form-data" \
         -F "deployment-name=order-processing.bpmn" \
         -F "data=@./src/main/resources/order-processing.bpmn"

5. Start a process instance using Camunda UI - tasklist option.

Receive task example

1. Deploy and Start the process using Camunda modeler or Curl command as mentioned above.

2. Process waits at the Receive Task until it receives the message with name SimpleNotifyRef and business key Example-9001, you can trigger the message using below curl command or using Camunda UI - Message option.

curl -X POST http://localhost:8080/engine-rest/message \
     --user demo:demo \
     -H "Content-Type: application/json" \
     -d '{
          "messageName": "SimpleNotifyRef",
          "businessKey": "Example-90001",
          "resultEnabled": true
         }'

Refer below links for more information

Camunda Docker Image

Camunda Rest API

Fetch and Lock external task

***NOTE: Implementation partially completed.***