Lab projects

Six projects that grow with the course. Each lists the topics it practises and a checklist; your ticks are saved in this browser.

1. Student record manager

Uses topics 1–4

A console program that stores students (ID, name, CGPA) in an array of Student objects and offers a menu: add, list, search by ID, update CGPA, show the topper and sort by CGPA.

Student class with private fields, constructor, getters and validating setters
Menu loop with do-while and switch
Array of objects with a count of how many are used
Linear search by ID and a sorting method you wrote yourself
toString() used for printing
Invalid input handled without crashing

2. Bank with transactions and exceptions

Uses topics 4–6, 10

Accounts with deposit, withdraw and transfer. Every account gets an automatic number from a static counter. Withdrawing too much throws your own InsufficientFundsException.

Account class with a static nextNumber and a final accountNo
Overloaded constructors using this(...)
Custom checked exception with a meaningful message
transfer(Account to, double amt) passing objects as parameters
try / catch / finally around each transaction
A transaction history stored with StringBuilder

3. Payroll with polymorphism

Uses topics 7–9

An abstract Employee with Salaried, Hourly and Commission subclasses, plus an Invoice class. Everything implements Payable, so one loop computes the total payout.

UML class diagram drawn first
Abstract class with an abstract earnings() method
Subclasses calling super(...) and overriding toString()
Payable interface implemented by unrelated classes
Payable[] processed in one polymorphic loop
Classes organised into at least two packages

4. Threaded bank simulation

Uses topics 11

Several customer threads deposit and withdraw on shared accounts at random. First run it unsynchronized and show the lost updates; then fix it.

Customer implements Runnable
Start threads with start() and wait with join()
Demonstrate a race condition with a wrong final total
Fix it with synchronized methods or blocks
Add a bounded transaction queue using wait() / notifyAll()
Explain in comments how you avoid deadlock in transfer()

5. Big-number calculator

Uses topics 3, 12

A calculator for non-negative integers with hundreds of digits, stored as Strings: add, subtract, multiply and compare. Check your answers against BigInteger.

add() and subtract() working column by column
multiply() using the i + j + 1 column rule
compare() without converting to numbers
Input validation with clear error messages
Factorial of 50 computed with your multiply()
Automatic tests comparing every result with BigInteger

6. CGPA tracker with JavaFX and a database

Uses topics 13

A desktop app where a student enters courses, credits and grade points. Records are saved in a MySQL/SQLite table and the CGPA is recalculated and drawn as a bar chart on a Canvas.

Form built with GridPane, TextField, ComboBox and Button
Event handlers written as lambdas
JDBC insert and select using PreparedStatement
Rows converted to Course objects in a TableView
Canvas bar chart of grade points
Database work done off the UI thread