{"id":21595084,"url":"https://github.com/chriseborowski/walletone","last_synced_at":"2025-03-18T10:44:03.392Z","repository":{"id":251808065,"uuid":"838504095","full_name":"chriseborowski/walletone","owner":"chriseborowski","description":"A robust Java-based virtual credit card management system featuring constant-time operations, multi-key indexing, and scalable architecture. Utilizes HashMaps for O(1) lookups, implements memory-efficient data structures, and supports multi-user card management. Offers card addition, removal, card/user searches, and card info display.","archived":false,"fork":false,"pushed_at":"2024-08-27T19:20:59.000Z","size":183,"stargazers_count":1,"open_issues_count":0,"forks_count":0,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-01-24T17:17:35.755Z","etag":null,"topics":["command-line","command-line-tool","credit-card","credit-card-management","credit-card-management-system","credit-card-manager","credit-card-menu-interaction","finance-management","financial-technology","java","java-app","virtual-credit-card"],"latest_commit_sha":null,"homepage":"https://github.com/chriseborowski/walletone","language":"Java","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"mit","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/chriseborowski.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE.md","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2024-08-05T19:20:05.000Z","updated_at":"2024-12-24T21:23:49.000Z","dependencies_parsed_at":"2024-08-27T21:05:46.903Z","dependency_job_id":null,"html_url":"https://github.com/chriseborowski/walletone","commit_stats":null,"previous_names":["chriseborowski/walletone"],"tags_count":0,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/chriseborowski%2Fwalletone","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/chriseborowski%2Fwalletone/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/chriseborowski%2Fwalletone/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/chriseborowski%2Fwalletone/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/chriseborowski","download_url":"https://codeload.github.com/chriseborowski/walletone/tar.gz/refs/heads/main","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":244207583,"owners_count":20416098,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["command-line","command-line-tool","credit-card","credit-card-management","credit-card-management-system","credit-card-manager","credit-card-menu-interaction","finance-management","financial-technology","java","java-app","virtual-credit-card"],"created_at":"2024-11-24T17:26:19.240Z","updated_at":"2025-03-18T10:44:03.364Z","avatar_url":"https://github.com/chriseborowski.png","language":"Java","funding_links":[],"categories":[],"sub_categories":[],"readme":"# WalletOne: Virtual Credit Card Management System\n\n  \u003cimg src=\"wallet one/images/WalletOne-Virtual-Credit-Card-Management-System-Java-app-logo.jpg\" alt=\"WalletOne: Virtual Credit Card Management System\" title=\"WalletOne: Virtual Credit Card Management System\" /\u003e\n\nWalletOne is a robust Java-based virtual credit card management system designed for efficient handling of card information, user data, and related operations, all in the command-line interface (CLI). For a detailed description and overview of WalletOne's main functionalities, see this blog post: [Introducing WalletOne: An Interactive Java Backend App Featuring a Virtual Credit Card Management System](https://chriseborowski.notion.site/Introducing-WalletOne-An-Interactive-Java-Backend-App-Featuring-a-Virtual-Credit-Card-Management-Sy-ae31693fde4249f28a142ddda560f637).\n\n## Key Features\n\n- [x] Add and remove credit cards with unique card numbers\n- [x] Manage multiple users per card\n- [x] Search functionality by zip code and user name\n- [x] Display detailed card information\n- [x] Constant-time card lookup using hash-based data structures\n- [x] Efficient user management with multi-key indexing\n\n## Technical Highlights\n\n- **Constant-time Card Lookup**: Utilizes HashMap for O(1) card retrieval by card number\n- **Multi-key Indexing**: Implements separate HashMaps for zip code and name-based user lookups\n- **Memory-efficient User Storage**: Uses a shared User object across different indexes\n- **HashMap-based Card Storage**: \n  The `CardManager` class uses a `HashMap\u003cString, Card\u003e` (cardHashMap) for O(1) card retrieval by card number.\n- **Scalable Architecture**: Designed to handle a large number of cards and users efficiently\n\n## Installation\n\n1. Ensure you have Java Development Kit (JDK) 8 or higher installed on your system.\n2. Clone the repository:\n   \n`git clone https://github.com/chriseborowski/walletone.git`\n\n3. Navigate to the project directory:\n   \n`cd walletone`\n\n4. Compile the Java files:\n\n`javac -d bin src/walletone/*.java`\n\n## Usage\n\n1. Run the main application:\n\n`java -cp bin walletone.Main`\n\n2. Follow the on-screen prompts to interact with the system.\n\n## Class Structure\n\n- `Card`: Represents a credit card with associated users\n- `User`: Represents a card user with name and zip code\n- `CardManager`: Core class managing all card operations and user lookups\n- `Main`: Entry point of the application (not provided in the context, but assumed to exist)\n\n## Key Methods\n\n- `addNewCard`: Adds a new card to the system\n- `removeCard`: Removes a card and updates all related data structures\n- `addUserToCard`: Adds a new user to an existing card\n- `searchByZip`: Retrieves users by zip code\n- `searchByName`: Retrieves users by name\n- `showAllCards`: Displays information for all cards in the system\n\n## Performance Considerations\n\n- Card lookup: O(1) time complexity\n- User lookup by zip code or name: O(1) average case, O(n) worst case where n is the number of users with the same zip code or name\n- Adding/Removing cards: O(1) time complexity\n- Adding users to a card: O(1) amortized time complexity\n\n## Future Enhancements\n\n- Implement data persistence (database integration)\n- Add user authentication and authorization\n- Develop a graphical user interface (GUI)\n- Implement card transaction tracking and analysis\n\n## Contributing\n\nContributions are welcome! Please feel free to submit a pull request.\n\n## License\n\nThis project is licensed under the MIT License - see the [LICENSE.md](LICENSE.md) file for details.\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fchriseborowski%2Fwalletone","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fchriseborowski%2Fwalletone","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fchriseborowski%2Fwalletone/lists"}