Spring Batch Processing Demo

A Spring Batch application that reads customer data from SQL source, transforms it, and sends HTTP requests with XML payload.

Deps & Libs

• Spring Boot 3.5.3
• Spring Batch
• Spring Data JPA
• JAXB for XML processing
• H2 Database (for development)
• PostgreSQL (for production)
• Kubernetes for deployment

Running Locally

Prerequisites

• Java 21
• Maven

Steps

1. Clone the repository
2. Build the application:

   mvn clean package
   

3. Run the application:

   java -jar target/batch-processing-0.0.1-SNAPSHOT.jar
   

The application will:

1. Initialize an in-memory H2 database with sample customer data
2. Execute the batch job to process the data
3. Send HTTP requests with XML payload to the configured endpoint
4. Exit automatically after job completion

Configuration

The application can be configured through application.properties:

# Database Configuration
spring.datasource.url=jdbc:h2:mem:batchdb
spring.datasource.username=sa
spring.datasource.password=

# Target API endpoint
app.target.url=https://example.com/api/customers

Kubernetes Deployment

The application includes a Kubernetes CronJob configuration that runs the job once per hour.

Prerequisites

• Kubernetes cluster
• Docker registry to store the application image

Steps

1. Build the Docker image:

   docker build -t batch-processing:latest .
   

2. Push the image to your registry:

   docker tag batch-processing:latest your-registry/batch-processing:latest
   docker push your-registry/batch-processing:latest
   

3. Update the image reference in k8s-cronjob.yaml

4. Create the database credentials secret:

   kubectl create secret generic db-credentials \
     --from-literal=username=postgres \
     --from-literal=password=your-password
   

5. Apply the CronJob configuration:

   kubectl apply -f k8s-cronjob.yaml
   

Project Structure

• src/main/java/com/megasoft/batch_processing/model/ - Data models
• src/main/java/com/megasoft/batch_processing/repository/ - Database repositories
• src/main/java/com/megasoft/batch_processing/service/ - Services for HTTP requests
• src/main/java/com/megasoft/batch_processing/config/ - Batch job configuration
• src/main/java/com/megasoft/batch_processing/BatchProcessingApplication.java - Main application class