Nkwa Real Estate Expenditure Management System

Overview

This project implements an offline, locally-stored, command-line expenditure tracking application for Nkwa Real Estate Ltd, designed for DCIT308 semester project at the University of Ghana.
It uses custom-built data structures only (arrays, sets, maps, stacks, queues, heaps, etc.) and avoids all external libraries and Java Collections for business logic.

Features

• Expenditure Tracking: Record code, amount, date, phase, category, and account used for each expenditure.
• Category Management: Uniqueness enforced via sets. Search, add, edit, delete categories.
• Bank Account Ledger: Store, update accounts; each expenditure draws funds and updates balances.
• Receipt/Invoice Handling: Link receipts to expenditures; use queues/stacks for upload and review.
• Alerts: Min-heap based priority alerts for low balances and overspending.
• Analytics: Monthly burn rate, cost breakdown, simple profitability forecast.
• Search & Sort: Sort by category or date; search by time, category, cost range, or account.
• Persistence: All data stored in plain text files: accounts.txt, categories.txt, expenditures.txt, receipts.txt.
• CLI Menu: Menu-driven workflow for all actions.

Data Structures Used

• SimpleArrayList - dynamic arrays
• SimpleSet - uniqueness for categories
• SimpleMap - key-value mappings (accounts, expenditures)
• SimpleQueue - FIFO for receipts
• SimpleStack - LIFO for receipts
• MinHeap - alert priorities

File Structure

src/
  app/
    Main.java
    modules/
      (All modules, managers, entities)
    util/
      (Custom data structures)
  data/
    accounts.txt
    categories.txt
    expenditures.txt
    receipts.txt

Sample Data Files

accounts.txt

ACC001|Main Operations|5000.00
ACC002|Marketing|2500.00
ACC003|Sales|1000.00

categories.txt

Cement|Building material|gray
Printing|Marketing material|blue
TV Adverts|Promotion|red

expenditures.txt

Format: ID|Description|Amount|DateTime|Category|AccountID|ReceiptPath

EXP001|Cement purchase|1200.00|2025-07-01T09:15:00|Cement|ACC001|receipts/cement_receipt.pdf
EXP002|TV promo spot|500.00|2025-07-02T11:00:00|TV Adverts|ACC002|receipts/tv_invoice.jpg
EXP003|Brochure printing|300.00|2025-07-03T14:30:00|Printing|ACC002|
EXP004|Site sand|700.00|2025-07-05T10:20:00|Cement|ACC001|receipts/sand_receipt.pdf

Note: The 7th field (ReceiptPath) is optional and can be empty for expenditures without linked receipts.

receipts.txt

RCT001|EXP001|receipts/cement_july.pdf|2025-07-01T09:30:00
RCT002|EXP002|receipts/tv_spot.jpeg|2025-07-02T11:10:00
RCT003|EXP003|receipts/brochure.pdf|2025-07-03T14:35:00

How to Run

1. Compile:

   javac -d bin src/app/Main.java
   

2. Run:

   java -cp bin app.Main
   

java -jar "APP G68Xpense.jar"

3. Interact: Use the CLI menu to add/view/edit expenditures, manage categories/accounts, view alerts, and analytics.

4. Clean .class files recursively:

   find . -type f -name "*.class" -delete

5. ls "c:\blipping grounds\prjs\xpense\G68Xpense.jar"

6. java -jar G68Xpense.jar

Operation	Data Structure	Complexity
Add Expenditure	SimpleArrayList/Map	O(1)
Search by ID	Map	O(1)
Sort by Category/Date	Array	O(n log n)
Category Uniqueness	Set	O(n)
Receipt Process	Queue/Stack	O(1)
Alert Processing	MinHeap	O(log n)
Account Lookup/Update	Map	O(1)

Data Integrity & Rules

• Expenditure must reference valid bank account and category.
• Adding expenditure always debits account atomically.
• Category names are unique.
• Alerts for low balances and overspending.

Authors

• Group 68, University of Ghana

License

• Educational use only.