Sprint Challenge: Task Management System

Bắt đầu bằng cách tạo các package tasks, management và main được mô tả trong issue, với Task và các kiểu task chuyên biệt, TaskManager và Main. Sử dụng các yêu cầu và tiêu chí chấp nhận được liệt kê để định hướng thiết kế, sau đó chạy Main để xác minh việc tạo và hoàn thành task, các bản tóm tắt đa hình và việc ngăn chặn các trạng thái không hợp lệ.

Sprint Challenge: Task Management System

The code you write for this challenge is mandatory homework and should be completed and sent in a PR for review before class.

This challenge combines all the object-orientated programming concepts you've learned so far. You'll see how classes, encapsulation, inheritance, polymorphism, packages, and static/final keywords form a cohesive system for building well-structured Java applications.

Background

You are working for a company that wants to track different types of tasks in a project. Each task has a description, a unique identifier, and a completion status. Some tasks have special behaviour or additional data, such as deadlines or priority levels.

Your job is to create a small system that models tasks, enforces valid state, and allows tasks to be managed using polymorphism.

Requirements

Design a system that models tasks, manages them, and prints a simple summary of task states to the console.

Task Behaviour

All tasks should:

• Have a unique identifier
• Have a human-readable description
• Be able to be completed
• Prevent invalid states, e.g. cannot be completed twice

Specialised Task Types

The system must support at least two specialised task types. These types should:

• Inherit from the base Task class
• Add additional state or behaviour of their own
• Behave differently at runtime when treated as a generic Task

Some examples could be a timed task with a deadline, or priority task with prioritisation

Task Management

Create a TaskManager class responsible for:

• Storing tasks (using a fixed-size array, e.g. max 10 tasks)
• Adding new tasks
• Completing tasks by ID
• Returning tasks based on completion status
• The TaskManager should not need to know concrete task types

Code Organisation

Your code should be organised into multiple packages:

• tasks → contains Task and specialised task types
• management → contains TaskManager
• main → contains Main class with a main method to demonstrate behaviour

Acceptance Criteria

The system should:

• Log task summaries to the console in a human-readable format
• Show each task's ID, description, type, and completion status
• Demonstrate polymorphism at runtime (e.g., calling overridden methods on different task types without checking type)
• Prevent any task from entering an invalid state
• Compile and run without errors
• Use proper encapsulation (no public fields)
• Use final or static where appropriate

Main method expectations:

• Create a TaskManager
• Add several different task types
• Complete some tasks
• Print task summaries to the console

Developer Guidance (May just use for reference)

Let's start by modelling the data:

Class Task

• Fields:
• private final int id (unique)
• private String description
• private boolean completed
• Methods:
• public void complete() → mark as completed, prevent double-completion
• public String getStatus() → returns a human-readable status
• Consider using static for generating unique IDs

Specialised Tasks

• Create at least two subclasses (e.g., TimedTask, PriorityTask)
• Add additional fields (e.g., deadline, priority)
• Override methods to demonstrate polymorphic behaviour

TaskManager

• Fields:
• private Task[] tasks
• private int taskCount
• Methods:
• public void addTask(Task task)
• public void completeTask(int id)
• public Task[] getTasksByStatus(boolean completed)

Main

• Create a simple demo of your system, showing tasks being added, completed, and summaries printed

Reflection Questions

• Where did polymorphism remove the need for conditional logic?
• Which responsibilities are shared across all tasks, and which are specific?
• Where did encapsulation prevent misuse of an object?
• If a new task type were added, how much existing code would need to change?

Submission & Review

Fork the coursework repo to your own GitHub account.
Make regular small commits with clear messages.
When you are ready, open a Pull Request to the CYF repo. Make sure you fill in the PR template provided.
A volunteer will review your submission and send you feedback.