Java 7 Batch Transaction Processor

Enterprise-grade batch transaction processing application implemented for Java 7. It ingests transaction files, applies JDBC-managed transactions with retry and isolation semantics, produces audit reports for failures, and is designed for robust, observable batch runs in production environments.

Key Features

• High-throughput CSV batch ingestion
• Manual JDBC transaction management for ACID guarantees
• Multithreaded processing using ExecutorService with controlled concurrency
• Retry-with-isolation for transient failures and per-record failure tracking
• Audit and summary report generation for failed and processed records
• Configurable via properties files; logging with Log4j

Architecture Overview

The application is organized into clear layers:

• controller — job entry point and argument parsing (BatchJobController)
• processor — business logic for transforming and validating records
• dao — database access and transaction management (TransactionDaoImpl)
• util — helpers for DB connections, file reading, reporting, and failure tracking

See the source tree under src/main/java/com/enterprise/batch for details.

Tech Stack

• Java 7
• Maven
• PostgreSQL (JDBC driver included)
• Log4j 1.2
• JUnit 4 for unit tests

Prerequisites

• Java 7 JDK
• Maven 3.x
• PostgreSQL (or compatible JDBC-accessible RDBMS)
• A terminal or IDE capable of building/running Maven projects

Getting Started

1. Clone the repository:

   git clone https://github.com/Nitish-Naik/java7-batch-transaction-processor.git cd java7-batch-transaction-processor

2. Create the database schema:

   • Apply the SQL in databaseSchema/schema.sql.
   • See databaseSchema/accounts.md and databaseSchema/transactions.md for schema notes.

3. Configure database connection and logging:

   • Edit src/main/resources/db.properties with your JDBC URL, username, and password.
   • Adjust logging in src/main/resources/log4j.properties as needed.

4. Build the project:

   mvn clean package

   The project produces a shaded, runnable JAR: target/transaction-processor-1.0-SNAPSHOT.jar (main class: com.enterprise.batch.controller.BatchJobController).

5. Run the batch job (example):

   java -jar target/transaction-processor-1.0-SNAPSHOT.jar /path/to/transactions.csv

   • The application accepts a CSV file path as the primary argument. For advanced options, run the job from your IDE and inspect BatchJobController.

Configuration

• src/main/resources/db.properties — database connection settings (JDBC URL, user, password)
• src/main/resources/log4j.properties — logging configuration

Keep sensitive credentials out of source control for production; prefer externalized configuration or environment variables.

Database Schema & Migrations

The canonical schema and notes live in the databaseSchema/ directory:

• databaseSchema/schema.sql
• databaseSchema/accounts.md
• databaseSchema/transactions.md

Use your preferred migration tool (Flyway, Liquibase) in production to manage schema changes.

Tests

Run unit tests with:

mvn test

Tests are implemented with JUnit 4. See src/test/java and src/main/java for examples (e.g., TransactionServiceTest).

Logging & Reports

• Log4j is used for application logging. Logs go to console by default; configure log4j.properties to change appenders/levels.
• Failed-record audit reports are generated by ReportGenerator in src/main/java/com/enterprise/batch/util/ReportGenerator.java.

Troubleshooting

• Common issue: database connectivity — verify db.properties and that the DB accepts connections from the host.
• If the job stalls, increase logging to DEBUG and inspect thread dumps; verify the executor configuration.

Contributing

Contributions are welcome. Suggested process:

1. Fork the repository.
2. Create a feature branch: feature/your-feature.
3. Add tests for new behavior.
4. Open a pull request with a clear description of the change.

Please follow Java 7 compatibility and keep changes minimal and well-tested.

License

This project is licensed under the MIT License — see LICENSE for details.

Contact

For questions or help, open an issue in this repository.

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