From 7367de1e6aa245c1022cd170687215799b207ec1 Mon Sep 17 00:00:00 2001 From: Romina Date: Fri, 22 May 2026 12:39:26 +0330 Subject: [PATCH] Exceptions and Files --- src/main/java/Main.java | 50 +++++++---- src/main/java/ReportGenerator.java | 133 ++++++++++++++--------------- 2 files changed, 99 insertions(+), 84 deletions(-) diff --git a/src/main/java/Main.java b/src/main/java/Main.java index 148a46e..75dba91 100644 --- a/src/main/java/Main.java +++ b/src/main/java/Main.java @@ -4,43 +4,59 @@ import java.util.ArrayList; import java.util.Collections; import java.util.Scanner; -public class Main { +public class Main +{ static ArrayList productCatalog = new ArrayList<>(); - public static void loadProducts() throws IOException{ + + public static void loadProducts() throws IOException + { InputStream input = Main.class .getClassLoader() .getResourceAsStream("products.csv"); - if (input == null) { + + if (input == null) + { throw new IOException("products.csv not found"); } - Scanner scanner = new Scanner(input); - // TODO: - // - Read each line from products.csv - // - For each line, parse productId, name, and price - // - The format of the file is like this: - // [productId],[name],[price] - // - Store Product objects in the productCatalog ArrayList + try (Scanner scanner = new Scanner(input)) + { + while (scanner.hasNextLine()) + { + String line = scanner.nextLine(); + if (line.isBlank()) continue; - // NOTE - // - The data in products.csv is guaranteed to be valid. + String[] parts = line.split(","); + + int id = Integer.parseInt(parts[0].trim()); + String name = parts[1].trim(); + double price = Double.parseDouble(parts[2].trim()); + + productCatalog.add(new Product(id, name, price)); + } + } } public static void main(String[] args) { - try { - loadProducts(); - } catch (IOException e) { + try + {loadProducts();} + catch (IOException e) + { System.err.println("Error reading products"); System.out.println("Terminating the program..."); return; } + System.out.println("=== Products loaded"); - ReportGenerator reportGenerator = new ReportGenerator("2025_order_details.csv", Collections.unmodifiableList(productCatalog)); + ReportGenerator reportGenerator = + new ReportGenerator("2025_order_details.csv", Collections.unmodifiableList(productCatalog)); + reportGenerator.processFile(); System.out.println("=== Order file processed"); + reportGenerator.saveReport(); System.out.println("=== Report saved as report.txt"); } -} +} \ No newline at end of file diff --git a/src/main/java/ReportGenerator.java b/src/main/java/ReportGenerator.java index 8eb458b..56d6154 100644 --- a/src/main/java/ReportGenerator.java +++ b/src/main/java/ReportGenerator.java @@ -1,83 +1,82 @@ -import java.util.List; - -public class ReportGenerator { +import java.io.*; +import java.util.*; +public class ReportGenerator +{ private final String ordersFilePath; private final List productList; + private double totalFinalCost = 0.0; + private int totalQuantity = 0; + private double totalDiscountValue = 0.0; + private int totalInvalidLines = 0; - private double totalFinalCost; - private int totalQuantity; - private double totalDiscountValue; - private int totalInvalidLines; - - public ReportGenerator(String ordersFilePath, List productList) { + public ReportGenerator(String ordersFilePath, List productList) + { this.ordersFilePath = ordersFilePath; this.productList = productList; } public void processFile() { - // TODO: - // 1. Open the order details CSV file - // 2. Read the file line by line - // 3. Split each line using comma delimiter - // (each line is guaranteed to contain exactly two commas) - // 4. Each line contains exactly 3 values in the format: - // [productId],[quantity],[discountPercent] - // 5. Attempt to convert values: - // - productId -> int - // - quantity -> int - // - discountPercent -> int - // NOTE: - // - quantity and discountPercent may contain invalid characters - // (e.g., letters instead of numbers). - // - If parsing any value fails (NumberFormatException), - // the entire line must be considered invalid. - // - Use try-catch blocks and exception handling to safely - // handle parsing and validation errors without stopping - // the processing of the remaining lines. - // 6. Validate parsed values: - // - productId must be greater than 0 - // - quantity must be greater than 0 - // - discountPercent must be between 0 and 99 inclusive - // 7. Look for a Product in productList that matches productId - // 8. If no Product with that ID exists in the catalog, - // the entire line is considered invalid - // 9. If all values are valid and the product exists, calculate: - // subtotal = quantity * product price - // discountValue = subtotal * discountPercent / 100 - // finalCost = subtotal - discountValue - // 10. Update report totals: - // - totalQuantity += quantity - // - totalFinalCost += finalCost - // - totalDiscountValue += discountValue - // 11. If any parsing error, validation failure, or missing product occurs: - // - increment totalInvalidLines - // - skip the line and continue processing the next line - // 12. Close all file resources + Map productMap = new HashMap<>(); + for (Product p : productList) + { + productMap.put(p.getProductID(), p); + } + + try (BufferedReader reader = new BufferedReader(new FileReader(ordersFilePath))) + { + String line; + while ((line = reader.readLine()) != null) + { + try + { + String[] parts = line.split(","); + if (parts.length != 3) throw new Exception("Invalid format"); + + int productId = Integer.parseInt(parts[0].trim()); + int quantity = Integer.parseInt(parts[1].trim()); + int discountPercent = Integer.parseInt(parts[2].trim()); + + Product product = productMap.get(productId); + + if (productId <= 0 || quantity <= 0 || discountPercent < 0 || discountPercent > 99 || product == null) + { + throw new Exception("Validation failed"); + } + + double subtotal = quantity * product.getPrice(); + double discountVal = subtotal * discountPercent / 100.0; + double finalCost = subtotal - discountVal; + + totalQuantity += quantity; + totalFinalCost += finalCost; + totalDiscountValue += discountVal; + + } + catch (Exception e) {totalInvalidLines++;} + } + } + catch (IOException e) + { + System.err.println("Error reading file: " + e.getMessage()); + } } public void saveReport() { - // TODO: - // 1. Build a formatted report string - // 2. Include: - // - total quantity - // - total final cost - // - total discount value - // - total invalid lines - // 3. Create/open output report file (name it report.txt) - // 4. Write report string into file - // 5. Handle file writing exceptions - // 6. Close writer resources - - /* Example Structure - ========= SALES REPORT ========= - Total Quantity Sold: 42 - Total Final Cost: $1520.75 - Total Discount Value: $230.50 - Invalid Rows: 3 - ================================ - */ + try (PrintWriter writer = new PrintWriter(new FileWriter("report.txt"))) + { + writer.println("========= SALES REPORT ========="); + writer.println("Total Quantity Sold: " + totalQuantity); + writer.printf("Total Final Cost: $%.2f%n", totalFinalCost); + writer.printf("Total Discount Value: $%.2f%n", totalDiscountValue); + writer.println("Invalid Rows: " + totalInvalidLines); + writer.println("================================"); + } + catch (IOException e) + { + System.err.println("Error writing report: " + e.getMessage()); + } } } \ No newline at end of file -- 2.54.0