Camunda 8 - Develop Workers (Java) - Lab

Lab project for the Camunda 8 - Develop Workers (Java) course on Camunda Academy.

This course gives a detailed hands-on experience on developing workers using Camunda. During the course, you will review basic and advanced job worker configurations — including timeout and variable fetching — to better understand how they work and how to optimize your project.

Difficulty: Intermediate | Time: ~1h 30min | Platform: Camunda 8.10+

• Describe how Job Workers implement business logic in Camunda
• Recognize and configure job activation settings: Timeout, FetchVariables
• Implement, run, and test timeout and variable-fetching behavior
• Recognize configuration and errors when completing and failing jobs
• Implement output variables on job completion

The Order Process (orderProcess) is a BPMN process with three service tasks executed by Java job workers:

• Awareness of Camunda and Job Workers
• Competent with BPMN and Java

Recommended preparatory courses:

• Camunda - Technical Overview
• Camunda - Develop your first job worker (Java)
• Camunda - Error Handling

• Java 21+
• Maven 3.x
• An IDE (Eclipse, IntelliJ, or VS Code)
• A Camunda 8 SaaS account with a running cluster and client credentials

For Camunda 8.10, configure the Java client with the CAMUNDA_* environment variables. The client reads these variables when CamundaClient.newClientBuilder().build() is called. Set the values for your cluster before running:

Use the endpoints and OAuth credentials provided for your Camunda cluster. Addresses must include a URI scheme such as https://. The Java client uses REST by default; configure the gRPC address when using gRPC.

If your environment already defines ZEEBE_REST_ADDRESS, map it to the variable expected by the Camunda Java Client before launching:

export CAMUNDA_REST_ADDRESS="$ZEEBE_REST_ADDRESS"

When running from VS Code, make sure the CAMUNDA_* variables are available to the Java run/debug process, not only to a separate terminal session. The 8.10 client does not use ZEEBE_REST_ADDRESS as a substitute for CAMUNDA_REST_ADDRESS.

mvn clean package

mvn exec:java -Dexec.mainClass="com.camunda.academy.OrderApplication"

Before running: deploy src/main/resources/order.bpmn to your cluster using Camunda Modeler or the Web Modeler.

The application will:

1. Create one process instance with randomized order variables (product name, price, promotion code, etc.).
2. Start three job workers that poll for and complete jobs of types trackOrderStatus, packItems, and processPayment.
3. Wait for user input — press any integer and Enter to shut down the workers gracefully.

src/main/java/com/camunda/academy/
├── OrderApplication.java          # Entry point — creates client, instances, and workers
├── FakeRandomizer.java            # Generates random order variables using JavaFaker
├── handler/
│   ├── OrderHandler.java          # Job handler for trackOrderStatus
│   ├── PackItemsHandler.java      # Job handler for packItems
│   └── ProcessPaymentHandler.java # Job handler for processPayment
└── services/
    └── TrackingOrderService.java  # Business logic called by all handlers
src/main/resources/
└── order.bpmn                     # BPMN process definition

The project uses Camunda Java client 8.10.6, and the project builds successfully against this version.