cescoffier/quarkus-kafka-demo

Quarkus Reactive Demo

Build

mvn clean package

Run / Demo

Prerequisites

docker-compose up

Payment Service

Important topics

• Usage of an Emitter to send a message to Kafka
• Kafka configuration (`application.properties)
• Usage of JSON-B to map Payment to String`

cd payment-service
mvn compile quarkus:dev

Listening on port 8081.

Send payments with:

http :8081/payment account=1111 amount:=10
http :8081/payment account=1112 amount:=520
http :8081/payment account=1113 amount:=50
http :8081/payment account=1111 amount:=45
http :8081/payment account=1112 amount:=22
http :8081/payment account=1113 amount:=345
http :8081/payment account=1111 amount:=3
http :8081/payment account=1112 amount:=67
http :8081/payment account=1113 amount:=99
http :8081/payment account=1111 amount:=100
http :8081/payment account=1112 amount:=345
http :8081/payment account=1113 amount:=678

Optional: Use Kafka Tool to check topic content:

1. Connect to localhost
2. Navigate to Clusters -> Topics -> Transactions
3. Click on data
4. Click on the green arrow

Transaction Viewer

Important topics

• From Kafka to Websocket
• Injection of stream (@Stream)

cd transaction-viewer
mvn compile quarkus:dev

Listening on port 8082

1. Open your browser to http://localhost:8082
2. By default, it shows the transactions for the account 1111.
3. Open me.escoffier.quarkus.reactive.TransactionSocket and change the account to 1112.
4. Save and refresh the browser
5. Send another payment:

http :8081/payment account=1112 amount:=1234

6. It should appear automatically

IMPORTANT: Do not refresh the browser, as the message have been acknowledged, you will only see the new ones.

Fraud Detector

Important topics

• Processing of stream to to complex stream logic

cd fraud-detector
mvn compile quarkus:dev

Listening on port 8083

1. Open your browser to http://localhost:8083
2. By default it detects fraud with a threshold set to 5000
3. Generate a fraud:

http :8081/payment account=1112 amount:=2234
http :8081/payment account=1112 amount:=200
http :8081/payment account=1112 amount:=300
http :8081/payment account=1112 amount:=2000
http :8081/payment account=1112 amount:=1000

4. The page should list it immediately
5. Edit me.escoffier.quarkus.reactive.FraudDetector and extend the threshold
6. Refresh the page

IMPORTANT: Do not refresh the browser, as the message have been acknowledged, you will only see the new ones.