Kitchen Inventory Manager

A simple Java CLI application to manage kitchen grocery items. Built as a university Object-Oriented Programming (OOP) assignment.

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Problem Statement

Managing kitchen inventory manually is inconvenient. Items run out, expire, or get forgotten. This application provides a simple menu-driven system to keep track of grocery items stored in the kitchen.

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Project Objective

Build a beginner-friendly Java application that demonstrates core OOP concepts:

• Classes and Objects
• Encapsulation
• Inheritance
• Functions (methods)
• Debugging

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Features

1. Add Item — store a new grocery item
2. View Items — display all items in the inventory
3. Search Item — find an item by name
4. Update Quantity — change the quantity of an existing item
5. Delete Item — remove an item from the inventory
6. Exit — close the application

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Technologies Used

• Language : Java (Core Java only)
• Interface : Command Line Interface (CLI)
• Input : Scanner class
• Storage : ArrayList (in-memory, no database)

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Project Structure

KitchenInventoryManager/
│
├── src/
│   ├── Item.java            → Base class (Encapsulation)
│   ├── PerishableItem.java  → Subclass (Inheritance)
│   ├── Inventory.java       → CRUD operations on ArrayList
│   └── Main.java            → Menu, input handling, driver code
│
├── README.md
├── DebuggingReport.md
└── .gitignore

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Explanation of Every Class

Item.java

The base class that represents a single grocery item.

All fields are private (Encapsulation):

• id → unique item number
• name → item name (e.g. Milk)
• category → item category (e.g. Dairy)
• quantity → how many units are available
• expiryDate → expiry date as a string (e.g. 25-07-2026) or N/A

Methods:

• displayItem() → prints all item details on screen
• Getters and Setters for every field

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PerishableItem.java

Extends Item to demonstrate Inheritance.

• Uses super() in its constructor to pass values to Item
• Overrides displayItem() using @Override to also print "Type : Perishable Item"

This class is intentionally kept simple. Its only purpose is to show how one class can inherit from another in Java.

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Inventory.java

Manages the collection of items using ArrayList<Item>.

Methods:

• addItem(Item item) → adds an item to the list
• viewItems() → prints all items
• searchItem(String name) → finds items by name
• updateItem(int id, int qty) → updates quantity for a given ID
• deleteItem(int id) → removes item by ID

No other logic exists in this class.

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Main.java

The entry point of the application.

Responsibilities:

• Displays the menu using printMenu()
• Reads user input using Scanner
• Calls appropriate Inventory methods based on the user's choice
• Contains a helper method readInt() to safely read integers

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How CRUD Works

Operation	Method Called	What Happens
Create	addItem()	New Item object added to ArrayList
Read	viewItems()	Loops through list and prints items
Search	searchItem()	Finds item by matching name
Update	updateItem()	Finds item by ID, sets new quantity
Delete	deleteItem()	Finds item by ID, removes from list

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OOP Concepts Demonstrated

Encapsulation

All fields in Item.java are declared private. They cannot be accessed directly from outside the class. Access is provided only through public getter and setter methods.

Example:

private int quantity;           // cannot be accessed directly

public int getQuantity() {      // controlled read access
    return quantity;
}

public void setQuantity(int quantity) {  // controlled write access
    this.quantity = quantity;
}

Inheritance

PerishableItem extends Item. It inherits all fields and methods from Item without rewriting them. It overrides displayItem() to add extra output.

Example:

public class PerishableItem extends Item {
    public PerishableItem(int id, String name, String category,
                          int quantity, String expiryDate) {
        super(id, name, category, quantity, expiryDate); // calls Item constructor
    }

    @Override
    public void displayItem() {
        super.displayItem();                             // calls Item's method
        System.out.println("Type : Perishable Item");
    }
}

Classes and Objects

Four classes are defined: Item, PerishableItem, Inventory, Main.

Objects are created in Main.java:

Item item = new Item(1, "Rice", "Grains", 10, "N/A");
PerishableItem milk = new PerishableItem(2, "Milk", "Dairy", 5, "25-07-2026");

Functions (Methods)

Every action in the project is a method:

• addItem(), viewItems(), searchItem(), updateItem(), deleteItem()
• printMenu(), readInt(), displayItem()

Debugging

An intentional bug was introduced in updateItem() where quantity was accidentally increased instead of replaced. The bug was identified using the IDE debugger and fixed. See DebuggingReport.md for the full walkthrough.

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How Each Assignment Requirement is Satisfied

Requirement	How it is satisfied
Functions	Methods like addItem(), viewItems(), displayItem(), etc.
Classes	Item, PerishableItem, Inventory, Main
Objects	Item and PerishableItem instances created in Main.java
Encapsulation	Private fields + public getters/setters in Item.java
Inheritance	PerishableItem extends Item with super() and @Override
Debugging	Bug introduced, documented, debugged, and fixed

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Project Workflow

User launches app
       ↓
Menu is displayed
       ↓
User selects option (1–6)
       ↓
Main.java reads input and calls Inventory method
       ↓
Inventory performs operation on ArrayList<Item>
       ↓
Result is printed to console
       ↓
Menu repeats until user chooses Exit (6)

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Compilation Instructions

Open PowerShell or Command Prompt.

Navigate to the project folder:

cd "C:\Users\RuchaParmar\Downloads\Oops_Project\KitchenInventoryManager"

Compile all Java files:

javac src\Item.java src\PerishableItem.java src\Inventory.java src\Main.java

If javac is not found in PATH, use the full path: & "C:\Program Files\Java\jdk-26.0.1\bin\javac.exe" src\Item.java src\PerishableItem.java src\Inventory.java src\Main.java

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Execution Instructions

Run the application after compiling:

java src.Main

If java is not found in PATH, use the full path: & "C:\Program Files\Java\jdk-26.0.1\bin\java.exe" src.Main

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Sample Output

Welcome to Kitchen Inventory Manager!

==============================
  Kitchen Inventory Manager  
==============================
1. Add Item
2. View Items
3. Search Item
4. Update Quantity
5. Delete Item
6. Exit
==============================
Enter your choice: 1

--- Add New Item ---
Enter name: Milk
Enter category (e.g. Dairy, Grains): Dairy
Enter quantity: 5
Enter expiry date (dd-MM-yyyy) or N/A: 25-07-2026
Is this a perishable item? (y/n): y
Item added successfully!

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Future Improvements

• Save inventory to a file so data persists after the program exits
• Add expiry date validation
• Add a low stock alert when quantity drops below a threshold
• Allow updating item name and category, not just quantity

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Author

Name : Rucha Parmar
Task of : Oops
College : Charusat University Year : Fourth Year Engineering