https://github.com/no13bus/refactoring-java
https://github.com/no13bus/refactoring-java
Last synced: about 2 months ago
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- Host: GitHub
- URL: https://github.com/no13bus/refactoring-java
- Owner: no13bus
- Created: 2025-05-13T14:17:34.000Z (5 months ago)
- Default Branch: main
- Last Pushed: 2025-05-15T10:15:43.000Z (5 months ago)
- Last Synced: 2025-06-13T00:40:31.181Z (4 months ago)
- Language: Java
- Size: 29.3 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Movie Rental System Refactoring Project
This is a Java implementation of a movie rental system for generating customer rental statements. This project demonstrates how to refactor existing code to improve code quality and maintainability.
## Refactoring Report
### Preliminary Work
1. **Maven Project Structure Conversion**
- Converted the project to Maven structure for automated dependency management
- Established foundation for CI/CD pipelines and Docker deployment
- Standardized project structure for better developer understanding and collaboration
2. **Continuous Integration Setup**
- Configured CI workflow on GitHub to ensure each commit passes tests
- Set up failure notification mechanisms for quick issue discovery
- Created a safety net for the refactoring process to prevent regression issues
3. **Test Coverage Enhancement**
- Added comprehensive test cases, including basic functionality and boundary conditions
- Ensured existing functionality has clear validation criteria
- Used tests to confirm actual system behavior and guide refactoring decisions
### Refactoring Implementation Process
1. **Domain Model Clarification**
- Identified relationships between core models: Customer, MovieRental, and Movie
- Defined clear responsibility boundaries for each class according to the Single Responsibility Principle
- Redesigned data flow paths to avoid unnecessary data transformations
2. **Magic Constant Elimination**
- Replaced string constants with strongly-typed MovieType enumeration to enhance type safety
- Improved code readability and maintainability while reducing potential errors
- Provided better IDE support for code completion and checking
3. **Evolution of Calculation Logic Refactoring**
- Initial approach: Moved calculation logic to MovieRental class since calculations only depend on movie type and rental days
- Further consideration: As movie types and calculation rules increase, MovieRental would take on too many responsibilities
- Issue insight: This would bloat the MovieRental data class, making unit testing difficult
- Final decision: Applied Strategy pattern to separate calculation logic, maintaining the purity of data models
4. **Strategy Pattern Implementation**
- Abstracted pricing and points calculation logic for different movie types into strategy interfaces
- Implemented a strategy factory to manage different calculation strategy implementations
- Made the system more easily extensible for new movie types without modifying core business logic
5. **Core Business Logic Optimization**
- Refactored the statement method in RentalInfo class to clearly separate data retrieval and presentation logic
- Removed unnecessary data assembly code, directly obtaining required information from the Customer model
- Optimized output format to improve statement readability and professionalism
6. **Project Layer Optimization**
- Naturally formed clearer project layering through the application of the Strategy pattern
- Identified Customer, Movie, and MovieRental as pure data models, placing them in the model package
- Reorganized code into three layers: model, service, and strategy based on responsibilities
- Established clear dependency relationships and call directions
## Project Structure
```
src/
├── main/java/movierental/
│ ├── model/ # Data model classes
│ │ ├── Customer.java
│ │ ├── Movie.java
│ │ ├── MovieRental.java
│ │ └── MovieType.java
│ ├── service/ # Service layer
│ │ └── RentalInfo.java
│ └── strategy/ # Strategy pattern implementation
│ ├── RentalStrategy.java
│ ├── RegularMovieStrategy.java
│ ├── NewReleaseMovieStrategy.java
│ ├── ChildrenMovieStrategy.java
│ └── RentalStrategyFactory.java
└── test/java/movierental/ # Test classes
└── RentalInfoTest.java
```
## How to Run
### Prerequisites
- Java 21 or higher
- Maven 3.6.0 or higher
### Running Tests
```bash
mvn test
```
## Tech Stack
- Java 21
- JUnit 5
- Maven
- GitHub Actions (CI/CD)