PM2.5 CLI Visualizer

Overview

This is a simple Java CLI application that fetches, displays, and stores PM2.5 air quality data. The project is designed for educational purposes and demonstrates core Object-Oriented Programming (OOP) concepts.

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Features

• Fetch PM2.5 data from an external API
• Display data in the terminal
• Simple text-based visualization (e.g., bar chart)
• Save data to CSV file
• Load data from CSV file

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Technologies

• Java (pure Java, no frameworks)
• CLI (Command Line Interface)
• CSV file handling

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Project Structure

src/com/pm25app/
 ├── Main.java
 ├── display/           # CLI Display Logics
 ├── services/          # Functions
 ├── exceptions/        # Errors
 └── data/              # Input / Output Operations

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OOP Concepts Used

• Encapsulation → Data stored in model classes (e.g., PM25Record)
• Inheritance → Display implementations share common behavior
• Polymorphism → Different display types used through a common interface
• Interfaces → ApiClient, Storage, Display
• Generics → Storage for flexible data handling

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How to Run

1. Compile the project:

javac com/pm25app/Main.java

2. Run the program:

java com.pm25app.Main

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Example Commands

• fetch → Get data from API
• view → Display current data
• save → Save data to CSV
• load → Load data from CSV
• exit → Exit program

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Data Storage

• Data is stored in:

/data/data.csv

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