Step-by-Step Guide: Logistics Service Implementation & Testing

1. Environment Setup 🛠️

1.1 Install Core Dependencies

# Verify Java & Maven
java -version  # Requires 17+
mvn -v        # Requires 3.9+
Install Docker
sudo apt-get update && sudo apt-get install docker.io docker-compose  # Linux
brew install docker docker-compose  # Mac

1.2 Clone Repository

git clone https://github.com/your-org/logistics-service.git
cd logistics-service

2. Infrastructure Deployment 🐳

2.1 Start Containers

docker-compose up -d postgres kafka redis

2.2 Verify Services

# Check PostgreSQL
docker exec -it postgres psql -U postgres -c "SELECT 1"
Check Kafka
docker exec -it kafka kafka-topics --list --bootstrap-server localhost:9092
Check Redis
docker exec -it redis redis-cli PING

3. Service Configuration ⚙️

3.1 Create Environment File

cat <<EOF > .env
SPRING_DATASOURCE_URL=jdbc:postgresql://localhost:5432/logistics
SPRING_DATASOURCE_USERNAME=postgres
SPRING_DATASOURCE_PASSWORD=postgres
KAFKA_BOOTSTRAP_SERVERS=localhost:9092
FRAUD_THRESHOLD=0.85
EOF

3.2 Initialize PostgreSQL

docker exec -it postgres psql -U postgres -c "
  CREATE DATABASE logistics;
  \c logistics;
  CREATE TABLE deliveries (
    id SERIAL PRIMARY KEY,
    order_id VARCHAR(50) NOT NULL,
    destination_type VARCHAR(20) NOT NULL,
    status VARCHAR(20) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
  );
  CREATE TABLE fraud_blacklist (
    id SERIAL PRIMARY KEY,
    phone VARCHAR(20) NOT NULL UNIQUE,
    reason VARCHAR(255),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
  );
"

4. Build & Run ▶️

4.1 Build with Maven

mvn clean install -DskipTests

4.2 Run Service

mvn spring-boot:run -Dspring-boot.run.profiles=dev

Verify Startup:

2024-02-20T10:00:00 INFO  o.s.b.w.e.tomcat.TomcatWebServer - Tomcat started on port 8080

5. Testing Procedures 🧪

5.1 Unit Tests

mvn test

Key Test Classes:

DeliveryOrchestratorServiceUnitTest
FraudDetectionServiceTest

5.2 Integration Tests

mvn verify -Pintegration-test

Test Coverage:

PostgreSQL repository operations
Kafka event publishing/consumption
Redis cache interactions

5.3 Manual API Testing

Create Test Delivery:

curl -X POST http://localhost:8080/api/v1/deliveries \
  -H "Content-Type: application/json" \
  -d '{
    "orderId": "test_ord_1",
    "destinationType": "HOME",
    "recipient": {
      "phone": "+15551234567"
    }
  }'

Force Error Scenario:

curl -X POST http://localhost:8080/api/v1/deliveries \
  -H "X-TEST-MODE: FAIL_HDS" \
  -d '{"orderId": "fail_ord_1", "destinationType": "HOME"}'

6. Verification Steps ✔️

6.1 Check PostgreSQL Data

docker exec -it postgres psql -U postgres -d logistics -c "
  SELECT * FROM deliveries;
  SELECT * FROM fraud_blacklist;
"

6.2 Monitor Kafka Events

docker exec -it kafka kafka-console-consumer \
  --bootstrap-server localhost:9092 \
  --topic delivery-events \
  --from-beginning

6.3 Validate Redis Cache

docker exec -it redis redis-cli KEYS "*delivery*"

7. Troubleshooting 🚨

Common Issues Table:

Symptom	Diagnostic Command	Solution
PostgreSQL connection refused	docker logs postgres	Check .env connection string
Kafka consumer lag	docker exec kafka kafka-consumer-groups --describe	Increase partitions
High API latency	curl -o /dev/null -s -w '%{time_total}' http://localhost:8080/actuator/health	Check Redis connection pool

8. Cleanup 🧹

# Stop containers
docker-compose down
Remove test data
docker exec -it postgres psql -U postgres -c "DROP DATABASE logistics"

Next Steps ➡️

Set up CI/CD pipeline
Configure Prometheus monitoring
Implement chaos engineering tests

Pro Tip: Use the included test-data-generator.sh for load testing:

./scripts/test-data-generator.sh --orders 100 --threads 5

This guide ensures your Logistics Service is properly implemented and ready for integration with other microservices. For advanced scenarios, refer to the Integration Handbook.: Here's an optimized project structure for your Java/Maven/PostgreSQL Logistics Service with clear separation of concerns and enhanced testability:

logistics-service/
├── .github/                          # CI/CD workflows
│   └── workflows/
│       ├── ci.yml                    # Test on PR
│       └── release.yml               # Deployment
│
├── src/
│   ├── main/
│   │   ├── java/com/company/logistics/
│   │   │   ├── application/          # Main app config
│   │   │   │   └── LogisticsApp.java
│   │   │   │
│   │   │   ├── api/                  # Presentation layer
│   │   │   │   ├── v1/               # Versioned APIs
│   │   │   │   │   ├── DeliveryApi.java
│   │   │   │   │   └── FraudApi.java
│   │   │   │   ├── dto/              # Data transfer objects
│   │   │   │   │   ├── request/
│   │   │   │   │   └── response/
│   │   │   │   └── exception/        # Exception handlers
│   │   │   │
│   │   │   ├── core/                 # Domain layer
│   │   │   │   ├── model/
│   │   │   │   ├── service/
│   │   │   │   └── event/
│   │   │   │
│   │   │   ├── infrastructure/       # Infrastructure layer
│   │   │   │   ├── config/
│   │   │   │   ├── repository/       # PostgreSQL repositories
│   │   │   │   ├── kafka/
│   │   │   │   └── redis/
│   │   │   │
│   │   │   └── orchestration/        # Specialized packages
│   │   │       ├── hds/              # Home Delivery System
│   │   │       ├── dzn/              # Drop Zone Network
│   │   │       │   ├── qr/
│   │   │       │   ├── location/
│   │   │       │   └── cache/
│   │   │       └── fraud/            # Fraud Detection
│   │   │
│   │   └── resources/
│   │       ├── config/
│   │       │   ├── application.yml
│   │       │   ├── application-dev.yml
│   │       │   └── application-prod.yml
│   │       ├── db/
│   │       │   └── migration/        # Flyway migrations
│   │       └── kafka/
│   │           └── schemas/          # Avro schemas
│   │
│   └── test/                         # Mirror main structure
│       ├── java/
│       └── resources/
│           ├── test-config.yml
│           └── fixtures/             # Test data
│
├── docker/                           # Containerization
│   ├── compose/
│   │   ├── local/
│   │   └── test/
│   └── scripts/
│
├── docs/
│   ├── api/                          # OpenAPI specs
│   ├── architecture/                 # Diagrams
│   └── adr/                          # Architecture decisions
│
├── libs/                             # Shared libraries
│   └── common-model/                 # Cross-service DTOs
│
├── .env.example                      # Env template
├── Dockerfile
├── pom.xml
├── Makefile                          # Build shortcuts
└── README.md

Key Improvements:

Clean Architecture:
- Clear separation between api/core/infrastructure
- Domain logic isolated from delivery mechanisms
Enhanced Testability:
- Test packages mirror main structure
- Dedicated test fixtures
- Separate test configuration
Delivery System Specialization:
- Dedicated packages for HDS/DZN
- Explicit fraud detection module
Infrastructure Ready:
- Versioned API endpoints
- Containerization support
- Database migrations with Flyway
Cross-Cutting Concerns:
- Centralized exception handling
- Shared DTO definitions
- Event schemas management

Implementation Notes:

For PostgreSQL Operations:

// infrastructure/repository/
@Entity
@Table(name = "deliveries")
public class DeliveryEntity {
    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
@Column(name = "order_id")
private String orderId;

@Enumerated(EnumType.STRING)
@Column(name = "status")
private DeliveryStatus status;
// JPA-specific fields

}

Kafka Integration:

// infrastructure/kafka/
@Configuration
public class KafkaConfig {
    @Bean
    public ProducerFactory<String, DeliveryEvent> producerFactory() {
        // Avro serializer config
    }
}

DZN Components:

// orchestration/dzn/qr/
@Service
public class QrService {
    public String generateQr(Delivery delivery) {
        // QR generation logic
    }
}

This structure supports:

Easy onboarding with clear package boundaries
Independent development of delivery systems
Straightforward test automation
Gradual migration from monolithic systems
Clear upgrade paths for components

The libs/common-model folder is particularly important for ensuring compatibility with other services by sharing:

Event schemas
Common DTOs
Enum definitions
Exception types

# **Step-by-Step Guide: Logistics Service Implementation & Testing**

1. Environment Setup 🛠️

1.1 Install Core Dependencies

# Verify Java & Maven
java -version  # Requires 17+
mvn -v        # Requires 3.9+

# Install Docker
sudo apt-get update && sudo apt-get install docker.io docker-compose  # Linux
brew install docker docker-compose  # Mac

1.2 Clone Repository

git clone https://github.com/your-org/logistics-service.git
cd logistics-service

2. Infrastructure Deployment 🐳

2.1 Start Containers

docker-compose up -d postgres kafka redis

2.2 Verify Services

# Check PostgreSQL
docker exec -it postgres psql -U postgres -c "SELECT 1"

# Check Kafka
docker exec -it kafka kafka-topics --list --bootstrap-server localhost:9092

# Check Redis
docker exec -it redis redis-cli PING

3. Service Configuration ⚙️

3.1 Create Environment File

cat <<EOF > .env
SPRING_DATASOURCE_URL=jdbc:postgresql://localhost:5432/logistics
SPRING_DATASOURCE_USERNAME=postgres
SPRING_DATASOURCE_PASSWORD=postgres
KAFKA_BOOTSTRAP_SERVERS=localhost:9092
FRAUD_THRESHOLD=0.85
EOF

3.2 Initialize PostgreSQL

docker exec -it postgres psql -U postgres -c "
  CREATE DATABASE logistics;
  \c logistics;
  CREATE TABLE deliveries (
    id SERIAL PRIMARY KEY,
    order_id VARCHAR(50) NOT NULL,
    destination_type VARCHAR(20) NOT NULL,
    status VARCHAR(20) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
  );
  CREATE TABLE fraud_blacklist (
    id SERIAL PRIMARY KEY,
    phone VARCHAR(20) NOT NULL UNIQUE,
    reason VARCHAR(255),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
  );
"

4. Build & Run ▶️

4.1 Build with Maven

mvn clean install -DskipTests

4.2 Run Service

mvn spring-boot:run -Dspring-boot.run.profiles=dev

Verify Startup:

2024-02-20T10:00:00 INFO  o.s.b.w.e.tomcat.TomcatWebServer - Tomcat started on port 8080

5. Testing Procedures 🧪

5.1 Unit Tests

mvn test

Key Test Classes:

DeliveryOrchestratorServiceUnitTest
FraudDetectionServiceTest

5.2 Integration Tests

mvn verify -Pintegration-test

Test Coverage:

PostgreSQL repository operations
Kafka event publishing/consumption
Redis cache interactions

5.3 Manual API Testing

Create Test Delivery:

curl -X POST http://localhost:8080/api/v1/deliveries \
  -H "Content-Type: application/json" \
  -d '{
    "orderId": "test_ord_1",
    "destinationType": "HOME",
    "recipient": {
      "phone": "+15551234567"
    }
  }'

Force Error Scenario:

curl -X POST http://localhost:8080/api/v1/deliveries \
  -H "X-TEST-MODE: FAIL_HDS" \
  -d '{"orderId": "fail_ord_1", "destinationType": "HOME"}'

6. Verification Steps ✔️

6.1 Check PostgreSQL Data

docker exec -it postgres psql -U postgres -d logistics -c "
  SELECT * FROM deliveries;
  SELECT * FROM fraud_blacklist;
"

6.2 Monitor Kafka Events

docker exec -it kafka kafka-console-consumer \
  --bootstrap-server localhost:9092 \
  --topic delivery-events \
  --from-beginning

6.3 Validate Redis Cache

docker exec -it redis redis-cli KEYS "*delivery*"

7. Troubleshooting 🚨

Common Issues Table:

Symptom	Diagnostic Command	Solution
PostgreSQL connection refused	`docker logs postgres`	Check `.env` connection string
Kafka consumer lag	`docker exec kafka kafka-consumer-groups --describe`	Increase partitions
High API latency	`curl -o /dev/null -s -w '%{time_total}' http://localhost:8080/actuator/health`	Check Redis connection pool

8. Cleanup 🧹

# Stop containers
docker-compose down

# Remove test data
docker exec -it postgres psql -U postgres -c "DROP DATABASE logistics"

Next Steps ➡️

Set up CI/CD pipeline
Configure Prometheus monitoring
Implement chaos engineering tests

Pro Tip: Use the included test-data-generator.sh for load testing:

./scripts/test-data-generator.sh --orders 100 --threads 5

This guide ensures your Logistics Service is properly implemented and ready for integration with other microservices. For advanced scenarios, refer to the [Integration Handbook](https://your-org.github.io/docs).: Here's an optimized project structure for your Java/Maven/PostgreSQL Logistics Service with clear separation of concerns and enhanced testability:

logistics-service/
├── .github/                          # CI/CD workflows
│   └── workflows/
│       ├── ci.yml                    # Test on PR
│       └── release.yml               # Deployment
│
├── src/
│   ├── main/
│   │   ├── java/com/company/logistics/
│   │   │   ├── application/          # Main app config
│   │   │   │   └── LogisticsApp.java
│   │   │   │
│   │   │   ├── api/                  # Presentation layer
│   │   │   │   ├── v1/               # Versioned APIs
│   │   │   │   │   ├── DeliveryApi.java
│   │   │   │   │   └── FraudApi.java
│   │   │   │   ├── dto/              # Data transfer objects
│   │   │   │   │   ├── request/
│   │   │   │   │   └── response/
│   │   │   │   └── exception/        # Exception handlers
│   │   │   │
│   │   │   ├── core/                 # Domain layer
│   │   │   │   ├── model/
│   │   │   │   ├── service/
│   │   │   │   └── event/
│   │   │   │
│   │   │   ├── infrastructure/       # Infrastructure layer
│   │   │   │   ├── config/
│   │   │   │   ├── repository/       # PostgreSQL repositories
│   │   │   │   ├── kafka/
│   │   │   │   └── redis/
│   │   │   │
│   │   │   └── orchestration/        # Specialized packages
│   │   │       ├── hds/              # Home Delivery System
│   │   │       ├── dzn/              # Drop Zone Network
│   │   │       │   ├── qr/
│   │   │       │   ├── location/
│   │   │       │   └── cache/
│   │   │       └── fraud/            # Fraud Detection
│   │   │
│   │   └── resources/
│   │       ├── config/
│   │       │   ├── application.yml
│   │       │   ├── application-dev.yml
│   │       │   └── application-prod.yml
│   │       ├── db/
│   │       │   └── migration/        # Flyway migrations
│   │       └── kafka/
│   │           └── schemas/          # Avro schemas
│   │
│   └── test/                         # Mirror main structure
│       ├── java/
│       └── resources/
│           ├── test-config.yml
│           └── fixtures/             # Test data
│
├── docker/                           # Containerization
│   ├── compose/
│   │   ├── local/
│   │   └── test/
│   └── scripts/
│
├── docs/
│   ├── api/                          # OpenAPI specs
│   ├── architecture/                 # Diagrams
│   └── adr/                          # Architecture decisions
│
├── libs/                             # Shared libraries
│   └── common-model/                 # Cross-service DTOs
│
├── .env.example                      # Env template
├── Dockerfile
├── pom.xml
├── Makefile                          # Build shortcuts
└── README.md

Key Improvements:

Clean Architecture:
- Clear separation between api/core/infrastructure
- Domain logic isolated from delivery mechanisms
Enhanced Testability:
- Test packages mirror main structure
- Dedicated test fixtures
- Separate test configuration
Delivery System Specialization:
- Dedicated packages for HDS/DZN
- Explicit fraud detection module
Infrastructure Ready:
- Versioned API endpoints
- Containerization support
- Database migrations with Flyway
Cross-Cutting Concerns:
- Centralized exception handling
- Shared DTO definitions
- Event schemas management

Implementation Notes:

For PostgreSQL Operations:

// infrastructure/repository/
@Entity
@Table(name = "deliveries")
public class DeliveryEntity {
    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    @Column(name = "order_id")
    private String orderId;
    
    @Enumerated(EnumType.STRING)
    @Column(name = "status")
    private DeliveryStatus status;
    // JPA-specific fields
}

Kafka Integration:

// infrastructure/kafka/
@Configuration
public class KafkaConfig {
    @Bean
    public ProducerFactory<String, DeliveryEvent> producerFactory() {
        // Avro serializer config
    }
}

DZN Components:

// orchestration/dzn/qr/
@Service
public class QrService {
    public String generateQr(Delivery delivery) {
        // QR generation logic
    }
}

This structure supports:

Easy onboarding with clear package boundaries
Independent development of delivery systems
Straightforward test automation
Gradual migration from monolithic systems
Clear upgrade paths for components

The libs/common-model folder is particularly important for ensuring compatibility with other services by sharing:

Event schemas
Common DTOs
Enum definitions
Exception types

Step‐by‐Step Guide: Logistics Service Implementation & Testing - Wiz-DevTech/prettygirllz GitHub Wiki

Step-by-Step Guide: Logistics Service Implementation & Testing

1. Environment Setup 🛠️

1.1 Install Core Dependencies

Install Docker

1.2 Clone Repository

2. Infrastructure Deployment 🐳

2.1 Start Containers

2.2 Verify Services

Check Kafka

Check Redis

3. Service Configuration ⚙️

3.1 Create Environment File

3.2 Initialize PostgreSQL

4. Build & Run ▶️

4.1 Build with Maven

4.2 Run Service

5. Testing Procedures 🧪

5.1 Unit Tests

5.2 Integration Tests

5.3 Manual API Testing

6. Verification Steps ✔️

6.1 Check PostgreSQL Data

6.2 Monitor Kafka Events

6.3 Validate Redis Cache

7. Troubleshooting 🚨

8. Cleanup 🧹

Remove test data

Next Steps ➡️

Key Improvements:

Implementation Notes:

1. Environment Setup 🛠️

1.1 Install Core Dependencies

1.2 Clone Repository

2. Infrastructure Deployment 🐳

2.1 Start Containers

2.2 Verify Services

3. Service Configuration ⚙️

3.1 Create Environment File

3.2 Initialize PostgreSQL

4. Build & Run ▶️

4.1 Build with Maven

4.2 Run Service

5. Testing Procedures 🧪

5.1 Unit Tests

5.2 Integration Tests

5.3 Manual API Testing

6. Verification Steps ✔️

6.1 Check PostgreSQL Data

6.2 Monitor Kafka Events

6.3 Validate Redis Cache

7. Troubleshooting 🚨

8. Cleanup 🧹

Next Steps ➡️

Key Improvements:

Implementation Notes:

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