Search⌘ K
AI Features
Home
Courses
Modern Java: From Fundamentals to Advanced Architecture

Solution: The Expired Product Purge

Understand how to use Java Collections and Iterators to implement a solution that removes expired or out-of-stock product entries. This lesson guides you through parsing file data, iterating with an Iterator, and applying business rules to safely modify a list during iteration.

We'll cover the following...
Java 25
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class WarehouseManager {
    static class Product {
        String name;
        int stock;
        String status;
        public Product(String name, int stock, String status) {
            this.name = name;
            this.stock = stock;
            this.status = status;
        }
        @Override
        public String toString() {
            return name + " (Stock: " + stock + ", Status: " + status + ")";
        }
    }
    public static List<Product> loadProducts(String filePath) {
        List<Product> products = new ArrayList<>();
        try {
            List<String> lines = Files.readAllLines(Path.of(filePath));
            
            // Start loop at 1 to skip the CSV header row
            for (int i = 1; i < lines.size(); i++) {
                String line = lines.get(i);
                String[] parts = line.split(",");
                
                // Parse CSV columns
                String name = parts[0].trim();
                int stock = Integer.parseInt(parts[1].trim());
                String status = parts[2].trim();
                
                products.add(new Product(name, stock, status));
            }
        } catch (IOException e) {
            System.out.println("Error reading file: " + e.getMessage());
        }
        return products;
    }
    public static void removeUnsellableItems(List<Product> inventory) {
        Iterator<Product> it = inventory.iterator();
        
        while (it.hasNext()) {
            Product p = it.next();
            
            // Remove if Stock is 0 OR Status is Expired
            if (p.stock == 0 || p.status.equals("Expired")) {
                it.remove();
            }
        }
    }
    public static void main(String[] args) {
        System.out.println("--- Loading Inventory ---");
        List<Product> inventory = loadProducts(filePath);
        System.out.println("Loaded " + inventory.size() + " items.");
        
        // Print first 5 to verify loading
        if (!inventory.isEmpty()) {
             System.out.println("First 5 items: " + inventory.subList(0, Math.min(inventory.size(), 5)));
        }
        System.out.println("\n--- Purging Unsellable Items ---");
        removeUnsellableItems(inventory);
        System.out.println("Purge complete.");
        System.out.println("Remaining items: " + inventory.size());
        
        System.out.println("Active Inventory:");
        for (Product p : inventory) {
            System.out.println(" - " + p);
        }
    }
}
...