quickstarts/tutorials/workflow/java/combined-patterns

Combined Workflow Patterns

This tutorial demonstrates how several workflow patterns can be combined in a single, more realistic, workflow. Some of the workflow activities are using other Dapr APIs, such as state management, service invocation, and Pub/Sub.

Inspect the code

The demo consist of two applications:

• workflow-app is the main application that orchestrates an order process in the OrderWorkflow.
• shipping-app is a supporting service that is being called by the OrderWorkflow.

The OrderWorkflow combines task chaining, fan-out/fan-in, and waiting for external event patterns. The workflow contains a number of activities for order processing including checking inventory, register shipment, process payment and more with a final order status being returned with the results of the order. It uses compensating logic in case the shipment fails to get registered and the customer needs to be reimbursed for the payment.

graph LR
   SW((Start
   Workflow))
   EW((End
    Workflow))
   subgraph OrderWorkflow
   direction LR
    CHKI[Check inventory]
    CHKD[Check shipping
    destination]
    IF1{Success?}
    PAY[Process
    payment]
    UPD[Update
    inventory]
    REG[Register
    shipment]
    WAIT[Wait for
    confirmation]
    IF2{Success?}
    RI[Reimburse
    customer]
   end
   subgraph Shipping
    direction LR
    REG2[registerShipment]
    CHKD2[checkDestination]
   end
    SW --> CHKI
    SW --> CHKD <--> CHKD2
    CHKI --> IF1
    CHKD --> IF1
    IF1 --> PAY
    PAY --> UPD
    UPD --> REG -.->|pub/sub| REG2
    REG2 -.->|pub/sub| WAIT
    REG --> WAIT
    WAIT --> IF2
    IF2 -->|Yes| EW
    IF2 -->|No| RI
    RI --> EW

Run the tutorial

1. Use a terminal to navigate to the tutorials/workflow/java/combined-patterns folder.

2. Build and run the workflow-app project using Maven.

   cd workflow-app
   mvn clean -Dspring-boot.run.arguments="--reuse=true" spring-boot:test-run
   

3. In a separate terminal, build and run the shipping-app project using Maven.

   cd shipping-app
   mvn clean -Dspring-boot.run.arguments="--reuse=true" spring-boot:test-run
   

Note: notice that you are using the reuse=true property to make sure that both applications connect to the same infrastructure instead of creating its own. This is using Testcontainers, check the []reuse functionality documentation here](https://java.testcontainers.org/features/reuse/), as you might need to enable this feature.

4. Use the POST request in the order-workflow.http file to start the workflow, or use this cURL command:

   curl -i --request POST \
   --url http://localhost:8080/start \
   --header 'content-type: application/json' \
   --data '{"id": "b0d38481-5547-411e-ae7b-255761cce17a","orderItem" : {"productId": "RBD001","productName": "Rubber Duck","quantity": 10,"totalPrice": 15.00},"customerInfo" : {"id" : "Customer1","country" : "The Netherlands"}}'
   

   The input for the workflow is an Order object:

   {
       "id": "{{orderId}}",
       "orderItem" : {
           "productId": "RBD001",
           "productName": "Rubber Duck",
           "quantity": 10,
           "totalPrice": 15.00
       },
       "customerInfo" : {
           "id" : "Customer1",
           "country" : "The Netherlands"
       }
   }
   

   The app logs should come from both services executing all activities as follows:

   i.d.s.w.WorkflowAppRestController        : Received order: Order[id=b0d38481-5547-411e-ae7b-255761cce17a, orderItem=OrderItem[productId=RBD001, productName=Rubber Duck, quantity=10, totalPrice=15.00], customerInfo=CustomerInfo[id=Customer1, country=The Netherlands]]
   s.w.w.a.CheckShippingDestinationActivity : io.dapr.springboot.workflowapp.workflow.activities.CheckShippingDestinationActivity : Checking Shipping Destination for Order: b0d38481-5547-411e-ae7b-255761cce17a
   i.d.s.w.w.a.CheckInventoryActivity       : io.dapr.springboot.workflowapp.workflow.activities.CheckInventoryActivity : Received input: OrderItem[productId=RBD001, productName=Rubber Duck, quantity=10, totalPrice=15.00]
   i.d.s.w.w.a.ProcessPaymentActivity       : io.dapr.springboot.workflowapp.workflow.activities.ProcessPaymentActivity : Process Order Item Payment: OrderItem[productId=RBD001, productName=Rubber Duck, quantity=10, totalPrice=15.00]
   i.d.s.w.w.a.UpdateInventoryActivity      : io.dapr.springboot.workflowapp.workflow.activities.UpdateInventoryActivity : Received input: OrderItem[productId=RBD001, productName=Rubber Duck, quantity=10, totalPrice=15.00]
   i.d.s.w.w.a.RegisterShipmentActivity     : io.dapr.springboot.workflowapp.workflow.activities.RegisterShipmentActivity : RegisterShipmentActivity for OrderItem: Order[id=b0d38481-5547-411e-ae7b-255761cce17a, orderItem=OrderItem[productId=RBD001, productName=Rubber Duck, quantity=10, totalPrice=15.00], customerInfo=CustomerInfo[id=Customer1, country=The Netherlands]]
   i.d.s.w.WorkflowAppRestController        : Shipment registered for order ShipmentRegistrationStatus[orderId=b0d38481-5547-411e-ae7b-255761cce17a, isSuccess=true, message=]
   
   
   

5. Use the GET request in the order-workflow.http file to get the status of the workflow, or use this cURL command:

   curl --request GET --url "http://localhost:8080/output?instanceId=b0d38481-5547-411e-ae7b-255761cce17a"
   

   The expected serialized output of the workflow is:

   {"isSuccess":true,"message":"Order b0d38481-5547-411e-ae7b-255761cce17a processed successfully."}
   

   The Order ID is generated when making the request and is different each time.

6. Stop both applications by pressing Ctrl+C in each terminal.