Personal Task Manager (CLI Version)

A Command-Line Java Application designed to help users organize, manage, and track their personal tasks effectively.
Built using Core Java, OOP principles, and TestNG for comprehensive unit testing.
This project demonstrates a clean architecture with layered design and custom exception handling.

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Project Overview

The Personal Task Manager (CLI) is a backend system that allows you to:

• Create, update, and delete tasks
• Assign categories and priorities
• Set due dates and get overdue task reports
• Filter and sort tasks by category, status, and priority
• Generate simple reports and reminders via CLI

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Technology Stack

• Java 11: Core programming language
• Maven: Build and dependency management
• TestNG: Testing framework
• Collections Framework: ConcurrentHashMap, ArrayList for data storage
• Java Time API: LocalDateTime for timestamp management
• Enums: Type-safe constants for various categories

Project Structure

personal-task-manager/
├── src/
│   ├── main/java/
│   │   └── com/taskmanager/
│   │       ├── model/
│   │       │   ├── Task.java
│   │       │   ├── Category.java
│   │       │   └── Priority.java
│   │       ├── exception/
│   │       │   ├── TaskNotFoundException.java
│   │       │   ├── InvalidDateException.java
│   │       │   ├── DuplicateTaskException.java
│   │       │   └── TaskValidationException.java
│   │       ├── service/
│   │       │   ├── TaskService.java
│   │       │   ├── CategoryService.java
│   │       │   ├── NotificationService.java
│   │       │   └── ReportService.java
│   │       ├── repository/
│   │       │   ├── TaskRepository.java
│   │       │   └── CategoryRepository.java
│   │       ├── util/
│   │       │   ├── DateValidator.java
│   │       │   └── TaskValidator.java
│   │       └── App.java
│   └── test/java/
│       └── com/taskmanager/
│           ├── service/
│           │   ├── TaskServiceTest.java
│           │   ├── CategoryServiceTest.java
│           │   └── ReportServiceTest.java
│           ├── repository/
│           │   └── TaskRepositoryTest.java
│           └── util/
│               └── DateValidatorTest.java
│
├── pom.xml
└── README.md

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Core Components

Model Layer Defines data models:

• Task.java — title, description, due date, priority, status, timestamps.
• Category.java — category grouping.
• Priority.java — Enum with HIGH, MEDIUM, LOW values.

Repository Layer

• TaskRepository.java — stores tasks using a ConcurrentHashMap.
• CategoryRepository.java — manages in-memory categories.

Service Layer Implements business logic:

• TaskService.java — CRUD, filtering, sorting.
• CategoryService.java — manages categories.
• NotificationService.java — handles reminders.
• ReportService.java — generates reports and statistics.

Utility Layer

• DateValidator.java — validates date inputs.
• TaskValidator.java — checks rules and duplicates.

Exception Layer Custom exceptions:

• TaskNotFoundException
• InvalidDateException
• DuplicateTaskException
• TaskValidationException

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OOP & Core Java Concepts

| Concept         |            Example             |
|-----------------|--------------------------------|
| Encapsulation   | Getters/setters in `Task.java` |
| Abstraction     | Service interfaces             |
| Inheritance     | Exception hierarchy            |
| Polymorphism    | Method overriding              |
| Collections     | HashMap, ConcurrentHashMap     |
| Concurrency     | Thread-safe repository         |
| Date/Time API   | LocalDate, LocalDateTime       |

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Testing (TestNG)

Includes full TestNG suite with:

Test Areas

• CRUD operations
• Filtering and sorting
• Exception handling
• Overdue tasks validation

Dependencies

<dependencies>
    <dependency>
        <groupId>org.testng</groupId>
        <artifactId>testng</artifactId>
        <version>7.8.0</version>
        <scope>test</scope>
    </dependency>
</dependencies>

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How to Run

1️ Compile:

mvn clean compile

2️ Run App:

mvn exec:java -Dexec.mainClass="com.taskmanager.App"

3️ Run Tests:

mvn test

Key Testing Strategies Demonstrated:

-Exception Testing: Verifying that critical operations throw the correct custom exceptions (e.g., DuplicateTaskException, TaskNotFoundException) upon business rule violation using @Test(expectedExceptions = ...).

-Data-Driven Testing: Utilizing @DataProvider to test service methods against various sets of input data (e.g., different date formats, all priority levels) for maximum coverage.

-State-Based Testing: Asserting the system's state after complex transactions (e.g., verifying getTasksByStatus returns the exact subset of tasks after multiple status updates).

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Reports & Logging

• Reports: target/surefire-reports/
• Console: shows validation, exception, and CRUD logs

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Future Enhancements

• Database or JSON persistence
• Task import/export
• CLI color themes
• Jenkins CI/CD integration
• REST API layer for UI

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Author Ruby Fathima