Wallet Service Microservice

Spring Boot 4 application for managing digital wallets in a payments system. Supports user registration, wallet creation, deposits, withdrawals, and peer-to-peer transfers with atomic balance updates and transaction logging.

Overview

This repository provides a project skeleton for a RESTful microservice using Java 17, Gradle Kotlin DSL, Spring Data JPA, and PostgreSQL. The initial implementation covers user registration and wallet creation with full test coverage. Extend it to implement additional features per INSTRUCTIONS.md.

Distributed as a ZIP archive including Git history for tracking development progress.

Group: com.rs.payments. Version: 0.0.1-SNAPSHOT. Description: wallet-service.

Prerequisites

• Java 17 (JDK, enforced via toolchain)
• Gradle 8.x (via wrapper)
• Docker and Docker Compose (for local database and Testcontainers)
• IntelliJ IDEA or compatible IDE (recommended for Spring Boot and Gradle support)
• Git (for history inspection)

Local Setup

1. Extract the ZIP archive to a directory: unzip wallet-service.zip (or use GUI tool).
2. Navigate to the project root: cd wallet-service.
3. Inspect Git history: git log --oneline (demonstrates initial commits).
4. Import into IDE: Open as Gradle project in IntelliJ (File > Open > select build.gradle.kts).

Running the Application

Full Stack (Docker Compose)

Starts PostgreSQL and the application container. (Assumes docker-compose.yml presence; configure as needed.)

docker-compose up --build

• Application: http://localhost:8080
• Database: localhost:5432 (user: user, password: password, db: walletdb)
• Logs: Monitor via docker-compose logs -f

Stop with docker-compose down.

Development Mode (IDE/Gradle)

1. Start PostgreSQL: docker-compose up -d db.
2. Run application: ./gradlew bootRun (or IDE run configuration for main class).

Configuration uses application.yml for local datasource (update URL if needed).

API Documentation

• OpenAPI/Swagger UI: http://localhost:8080/swagger-ui.html
• OpenAPI JSON: http://localhost:8080/v3/api-docs

Endpoints (initial):

• POST /users: Create user.
• POST /wallets: Create wallet for user.

Code Quality Checks

Run static analysis tools via Gradle tasks.

• Checkstyle (main sources): ./gradlew checkstyleMain
• PMD (main sources, custom ruleset): ./gradlew pmdMain
• SpotBugs (main sources, HTML/XML reports in build/reports/spotbugs): ./gradlew spotbugsMain
• All checks: ./gradlew check (includes unit/integration tests)

Failures are ignored by default; review reports for issues.

Running Tests

Uses JUnit 5, Mockito, and Testcontainers for PostgreSQL. Tests in src/test/java; integration tests in src/integration/java (tagged @Tag("integration")).

• Unit tests: ./gradlew test
• Integration tests: ./gradlew integrationTest
• All tests: ./gradlew check
• Coverage report (JaCoCo, HTML in build/reports/jacoco/test/html/index.html, XML in build/reports/jacoco/test/jacocoTestReport.xml): ./gradlew jacocoTestReport (runs after tests)

Aim for 100% coverage on new code.

Building the Project

./gradlew build

Produces executable JAR: build/libs/wallet-service-0.0.1-SNAPSHOT.jar.

Run JAR: java -jar build/libs/wallet-service-0.0.1-SNAPSHOT.jar.

Clean build: ./gradlew clean build.

Database Schema

Hibernate DDL auto: update (dev only). Entities (using UUID for primary keys):

• users: id (UUID), username, email (unique).
• wallets: id (UUID), balance (one-to-one with user).
• transactions: id (UUID), amount, type, timestamp.

Further Development

Implement user stories in INSTRUCTIONS.md using TDD. Commit incrementally to the main branch with descriptive messages (e.g., "Add failing test for deposit endpoint").

For CI: .github/workflows/ci.yml runs on push/PR (adapt as needed).

Submission

To prepare the project for submission, run:

./gradlew prepareSubmission

This creates a ZIP file: submission-<your-username>-<date>.zip.

Important:

• If the file name ends with -anonymous, the submission will not be accepted.
• Ensure your git author name is set correctly:

  git config user.name "Your Name"
  git config user.email "your.email@example.com"

• Commit your changes before running the task.

Troubleshooting

• Port conflict: Change server.port in application.yml.
• Database connection: Verify Docker container health (docker ps); check logs.
• Gradle issues: ./gradlew clean and retry; ensure Java 17 via java -version.
• Tests fail: Ensure Docker for Testcontainers; use create-drop mode in tests.
• Lombok issues: Enable annotation processing in IDE.

For questions, refer to INSTRUCTIONS.md.