Java Internship Tasks

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Author

Name: Tushar Kumar

Internship provided by: Codveda Technologies

Duration: November 2025

Role: Java Development Intern

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Basic Task 1: Basic Calculator

Description

A simple Java console application that performs basic arithmetic operations - Addition, Subtraction, Multiplication, Division - based on user input.

This project demonstrate how to:

• Create and structure a java class with separate methods for each operation.
• Accept user inputs using the scanner class.
• Handle invalid inputs and division by zero cases gracefully.
• Display meaningful output in the console.

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Objectives

• Create a class with methods for each arithmetic operation.
• Take input from the user for numbers and the desired operation.
• Handle edge cases like division by zero.

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Basic Task 2 : Number Guessing Game

Description

A Java console game where the computer randomly selects a number and the user must guess it within a limited number of attempts.

This project demonstrate how to:

• Generates a random number between 1 and 100.
• Uses loops and conditionals to check each guess.
• Ends when the user guesses correctly or runs out of attempts.

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Objectives

• Use Java's Random class to generate a random number
• Provide feedback like "too high", "too low" or "correct"
• Limit the number of attempts
• Handle invalid (non-numeric) inputs

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Basic Task 3 : Factorial Calculation using Recursion

Description

A Java console application that calculates factorial of a given number using recursion.

This project demonstrate how to:

• Implements recursive functions in Java.
• Handles base and recursive cases effectively.
• Manage invalid inputs such as negative numbers.

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Objectives

• Implement a recursive method to compute the factorial.
• Handle edges cases like factorial of 0 = 1.
• Display appropriate messages for negative numbers or invalid inputs.

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Intermediate Task 1 : Employee Management System

Description

A Java console-based application that manages employee records using Object-Oriented Programming (OOP) concept. It allows user to perform CRUD (Create, Read, Update, Delete) operations on employee data stored in memory.

This project demonstrate how to:

• Create and uses classes and objects in Java.
• Manage data using collections like Arraylist.
• Implement CRUD functionality with user interaction via the console.
• Handle invalid inputs and edge cases effectively.

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Objectives

• Define an Employee class with fields such as ID, Name and Salary.
• Implements methods to Add, View, Update and Delete employee records.
• Use ArrayList to store employee data dynamically.
• Apply control structure loops, conditionals, switch for user menu navigation.
• Handle invalid or duplicate entries gracefully.

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Intermediate Task 2 : File Handling - Reading and Writing to a file

Description

A Java console-based application that demonstrate file handling by reading data form one text file, processing it (counting line and words) and writing the summary to another file.

This project demonstrate how to:

• Uses Java's BufferReader and BufferWriter for file I/O operations.
• Read content line by line from an input file.
• Process text to count total lines and words.
• Write the processed summary into an output file.
• Handle file-related exceptions such as FileNotFoundException and IOException.

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Objectives

• Read a text file and count the number of lines and words.
• Write the processed output to a new file.
• Handle exceptions gracefully to ensure reliable file operations.
• Display the summary result in the console for quick verification.

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Intermediate Task 3 : Simple Banking Application

Description

A Java console-based application that simulates simple banking operations such as depositing money, withdrawing funds and checking account balance.

This project demonstrate how to:

• Implement a BankAccount class with private fields and public methods.
• Use Java methods for deposit, withdrawal and balance checking.
• Applying condition checks (e.g.,insufficient balance).
• Create a menu-driven console interface for user interaction.
• Handle invalid inputs gracefully to avoid runtime issues.

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Objectives

• Create a BankAccount class with deposit(), withdraw() and checkBalance().
• Validate transactions to prevent invalid or insufficient withdrawals.
• Simulate continuous user interaction using loops and console input.
• Display clear transactions messages and updated balance information.

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Advanced Task 1 : Library Management System

Description

A Java console-based application that manages library operations such as adding books, registering users, borrowing and returning books and viewing transactions.

This project demonstrate how to:

• Implement a Book, User, and Transaction model classes.
• Build DAO (Data Access Object) layers for database interactions.
• Use MySQL with JDBC for CRUD operations.
• Manage book availability and quantity updates dynamically.
• Record all borrowing and returning activities using a transaction logs.
• Create a clean, menu-driven console interface for user interaction.
• Handle invalid data inputs and missing records gracefully.

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Objectives

• Design tables in MySQL (books, users, transactions) and connect them using JDBC.
• Implement methods to : addBooks(), addUser(), borrowBook(),returnBook(), getAllBooks(), getAllUsers(), getAllTransactions().
• Maintain book quantity and availability automatically.
• Log every borrow/return operations in transactions table.
• Provide continuously interactive console-based menu until exit.
• Ensure proper error messages when book/users are not found.

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Advanced Task 2 : Multi-Threaded Chat Application

Description

A Java console-based chat system that enables multiple users to communicate with each other in real-time using multithreading and Java Sockets.

This project demonstrate how to:

• Implement a Chat Server to handle incoming client connections.
• Use Client Handler threads to manage multiple clients simultaneously.
• Build a Chat Client program that sends and receives messages on separate threads.
• Manage book availability and quantity updates dynamically.
• Apply Socket programming Server Socket,Socket for networking.
• Use Input/Output streams for continuous message transfer.
• Create a real-time broadcast system for all connected clients.
• Handle client disconnections gracefully without stopping the server.

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Objectives

• Implement a server that listen for clients using Server Socket.
• Create a multithreaded architecture using a Client Handler class.
• Allow each client to send and receive real-time messages through the server.
• Broadcast one client's message to all other connected clients.
• Maintain continuous communication until exit is typed by the user.
• Display proper server and client messages (connection, disconnection, errors).
• Support multiple client instances using IntelliJ's Allow multiple instances option.

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Advanced Task 3 : Binary Search Tree (BST) Implementation

Description

A Java console-based implementation of a Binary Search Tree (BST) data structure wih core operations like insertion, deletion, searching and tree traversal in-roder, pre-order, post-order.

This project demonstrate how to:

• Define a Tree Node class for representing nodes in a tree.
• Implement insert(), search() and delete() operations in BST.
• Apply recursive traversal algorithms: In-order, Pre-order, Post-order.
• Understand and handle all deletion cases (leaf node, one child, two children).
• Use recursive efficiently for tree navigation.
• Work with hierarchical data structure in Java.
• Display BST elements in sorted and traversal order using console output.

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Objectives

• Create a Tree Node class with value, left, right references.
• Implement BST method: insert(), search(), delete(), in-roder, pre-order, post-order.
• Handle special cases while deleting: Node with no children, one child, two children.
• Ensure Tree structure remains valid after every operation.
• Display tree output clearly using console-based UI.
• Demonstrate recursion and decision-based traversal logic.

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Folder Structure

Java-Internship-Tasks
|--- src
|    |--- tasks
|            |--- basics
|            |    |--- Calculator
|            |    |--- NumberGuessingGame
|            |    |--- Factorial
|            |--- intermediate
|            |    |--- EmployeeManagementSystem
|            |    |--- FileHandlingTask
|            |    |--- BankingAppTask
|            |--- advanced
|            |    |--- Library
|            |    |     |--- app          ---> includes main file
|            |    |     |--- dao          ---> includes (Bank, Transaction, User) DAO
|            |    |     |--- models       ---> includes Bank, Transaction, User files
|            |    |     |--- service      ---> includes Library services
|            |    |     |--- DBConnection ---> connected to mysql
|            |    |--- Chat Application
|            |    |     |--- Chat Client   ---> Client Program
|            |    |     |--- Chat Server   ---> Main server
|            |    |     |--- Chat Handler  ---> Thread Handler for each Client
|            |    |--- BST
|            |    |     |--- Binary Search Tree
|            |    |     |--- BSTMain
|            |    |     |--- Tree Node
|--- sql
|    |---library_db
|--- README.md

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Technologies Used

• Language : Java
• IDE : IntelliJ IDEA
• Java Version : 17+
• Database : MySQL
• Database Connector: JDBC (MySQL Connector/J)
• Architecture : DAO (Data Access Object) Pattern
• Build/Execution : JDK compiler & Console-based application

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LinkedIn Profile

Tushar Kumar - [https://www.linkedin.com/in/tushar-kumar-developer/]