Week 1 – Assignment

Mini Project: Console-Based Student Management System (Phase 1)

🎯 Objective

Build a simple console-based Student Management System using pure Java (no collections yet).

This assignment focuses on:

OOP fundamentals
Encapsulation
Constructor validation
Clean code structure
Defensive programming
Separation of responsibility

This project will evolve in future weeks.

🏗 Project Requirements

You must implement the following classes:

1️⃣ Student Class

Fields (All Must Be Private)

studentId (String)
name (String)
age (int)
email (String)

Constructor Requirements

Constructor must:

Validate studentId is not null or empty
Validate name is not null or empty
Validate age is >= 16
Validate email contains “@”

If invalid → throw IllegalArgumentException

Example:

Age must be at least 16
Invalid email format

Methods

Getters for all fields
boolean isAdult() → returns true if age >= 18
Override toString() to print student details properly

Example output:

Student{id='S101', name='Riya', age=22, email='riya@email.com'}

2️⃣ StudentPrinter Class

Create a separate class:

StudentPrinter

It must:

Have method printStudent(Student student)
Print student details

Why separate class?

Because:

Model class should not handle printing logic.

This introduces separation of concerns.

3️⃣ Main Class

Create a Main class with main() method.

In main():

Step 1 – Create 3 Valid Students

Example:

S101 – Riya – 22 – riya@email.com
S102 – Aman – 17 – aman@email.com
S103 – Kavya – 19 – kavya@email.com

Step 2 – Print All Students

Use StudentPrinter.

Step 3 – Test Validation

Try creating:

Student with age < 16
Student with invalid email
Student with empty name

Wrap in try-catch and print error messages.

📦 Package Structure

Use proper package structure:

com.learnjava.week1.model
com.learnjava.week1.service
com.learnjava.week1

Example:

Student → model
StudentPrinter → service
Main → root package

🧠 Engineering Constraints

You MUST:

✔ Use private fields ✔ Use constructor validation ✔ Avoid public setters (unless justified) ✔ Follow naming conventions ✔ Keep methods short ✔ One class per file ✔ No static abuse ✔ Proper indentation

❌ What You Must NOT Do

🚫 Do not make fields public 🚫 Do not skip validation 🚫 Do not write everything inside main() 🚫 Do not use collections yet 🚫 Do not hardcode print logic inside Student

🛡 Defensive Programming Expectations

You should handle:

Null inputs
Empty strings
Invalid age
Invalid email
Object misuse attempts

Ask yourself:

Can someone create an invalid student?

If yes → fix design.

🧪 Manual Testing Requirements

Test the following scenarios:

Test Case	Expected Result
Valid student	Object created
Age < 16	Exception
Null name	Exception
Invalid email	Exception

Write test results in comments.

📊 Evaluation Criteria

Category	Marks
Encapsulation	/10
Constructor Validation	/10
Clean Code	/10
Separation of Responsibility	/10
Defensive Programming	/10

Total: /50

🌱 Future Evolution (Do Not Implement Yet)

This system will later:

Use Collections (Week 2)
Persist to file (Week 3)
Convert to REST API (Week 5)
Connect to database (Week 6)
Add unit tests (Week 7)
Dockerize (Week 8)

So design carefully.

🧠 Reflection Questions (Submit with PR)

Answer in a separate file reflection.md:

Why is constructor validation important?
Why did we avoid public setters?
Why separate StudentPrinter?
What happens if fields were public?
What design improvements would you suggest?

📌 Submission Process

Create feature branch:
```
week-1-assignment
```

Commit properly:

feat: implement student management system phase 1

Create Pull Request.
Add reflection answers.

🚀 End of Week Outcome

After completing this assignment, you should:

Build structured Java classes
Protect object state
Validate inputs properly
Understand separation of concerns
Think defensively
Follow clean coding standards