Implementation of WS-05 is completed

.idea/.name

@@ -0,0 +1 @@
+Main.java

src/main/java/org/Exceptions/FileService.java

@@ -1,92 +1,116 @@
 package org.Exceptions;
-
+import java.io.*;
+import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.Scanner;
+import java.util.InputMismatchException;
+/**
+ *
+ *
+ * @author Hesam Ghazi
+ * Student Number: 403222015
+ * @version 1.0
+ */
 
 public class FileService {
 
-
     public static void main(String[] args) {
-
         Scanner scanner = new Scanner(System.in);
 
-        System.out.println("Enter you first name: ");
-        String firstName = scanner.nextLine();
+        try {
+            System.out.println("Enter your first name: ");
+            String firstName = scanner.nextLine();
 
-        System.out.println("Enter you last name: ");
-        String lastName = scanner.nextLine();
+            System.out.println("Enter your last name: ");
+            String lastName = scanner.nextLine();
 
-        System.out.println("Enter your national code: ");
-        Long nationalCode = scanner.nextLong();
-        scanner.nextLine();
+            System.out.println("Enter your national code: ");
+            Long nationalCode = scanner.nextLong();
+            scanner.nextLine(); // consume newline
 
-        System.out.println("Enter your email: ");
-        String email = scanner.nextLine();
+            System.out.println("Enter your email: ");
+            String email = scanner.nextLine();
 
-        System.out.println("Enter your phone number: ");
-        Long phoneNumber = scanner.nextLong();
-        scanner.nextLine();
+            System.out.println("Enter your phone number: ");
+            Long phoneNumber = scanner.nextLong();
+            scanner.nextLine(); // consume newline
 
-        System.out.println("Enter your dateOfBirth: ");
-        String dateOfBirth = scanner.nextLine();
+            System.out.println("Enter your dateOfBirth (yyyy-MM-dd): ");
+            String dateOfBirth = scanner.nextLine();
 
-        UserEntity user = null;
+            Date dob = parseDate(dateOfBirth);
+            if (dob == null) {
+                System.err.println("Registration aborted due to invalid date format.");
+                return;
+            }
 
-        user = new UserEntity(firstName, lastName, nationalCode, email, phoneNumber, parseDate(dateOfBirth));
+            UserEntity user = new UserEntity(firstName, lastName, nationalCode, email, phoneNumber, dob);
 
-        System.out.println(user.toString());
+            System.out.println("\nCreated User Info:");
+            System.out.println(user.toString());
 
-        System.out.println(writeFile(user));
-        readFile();
+            System.out.println(writeFile(user));
 
+            System.out.println("\nReading top entries from file:");
+            readFile();
 
+        } catch (InputMismatchException e) {
+            System.err.println("Input format error: Please enter valid numbers for numeric fields.");
+        } catch (Exception e) {
+            System.err.println("An unexpected error occurred: " + e.getMessage());
+        } finally {
+            // Scanner should only be closed if it's the end of program usage
+            scanner.close();
+        }
     }
 
 
     public static String writeFile(UserEntity user) {
-        //TODO: Uncomment the lines below.
-        //TODO: Use your knowledge of exception handling to make the code work as expected
+        try (FileWriter fw = new FileWriter("userInformation.txt", true);
+             BufferedWriter bw = new BufferedWriter(fw)) {
 
-        /* Uncomment this section
-        //TODO: handle the exception
-        FileWriter fw = new FileWriter("userInformation.txt", true);
-        BufferedWriter bw = new BufferedWriter(fw);
+            bw.write(user.toString());
+            bw.newLine();
+            return "User information written to file successfully";
 
-        bw.write(user.toString());
-        bw.close();
-         */
-        return "user information written to file";
+        } catch (IOException e) {
+            System.err.println("Error writing to file: " + e.getMessage());
+            return "Failed to write user information to file";
+        }
     }
 
-
     public static void readFile() {
-        //TODO: Uncomment the lines below.
-        //TODO: Use your knowledge of exception handling to make the code work as expected
+        try (FileReader file = new FileReader("userInformation.txt");
+             BufferedReader fileInput = new BufferedReader(file)) {
 
-        /* Uncomment this section
-        FileReader file = new FileReader("userInformation.txt");
-
-        BufferedReader fileInput = new BufferedReader(file);
-
-        for (int counter = 0; counter < 3; counter++)
-            System.out.println(fileInput.readLine());
-
-        fileInput.close();
-         */
+            String line;
+            int counter = 0;
+            while ((line = fileInput.readLine()) != null && counter < 3) {
+                System.out.println(line);
+                counter++;
+            }
+            if (counter == 0) {
+                System.out.println("The file is empty or no lines to read.");
+            }
+        } catch (FileNotFoundException e) {
+            System.err.println("File not found: " + e.getMessage());
+            System.err.println("Please ensure userInformation.txt exists and has been created.");
+        } catch (IOException e) {
+            System.err.println("Error reading from file: " + e.getMessage());
+        }
     }
 
-
     public static Date parseDate(String date) {
         SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
-
-        Date dob = null;
-
-        //TODO: Uncomment this line.
-        //TODO: Use your knowledge of exception handling to make the code work as expected
-        //dob = formatter.parse(date);
-
-        return dob;
+        // Ensure parsing strictly follows pattern lengths (e.g. rejects 1990-15-55)
+        formatter.setLenient(false);
+        try {
+            return formatter.parse(date);
+        } catch (ParseException e) {
+            System.err.println("Error parsing date: " + e.getMessage());
+            System.err.println("Please use the format yyyy-MM-dd (e.g., 1990-01-15)");
+            return null;
+        }
     }
-
-}
+}

src/main/java/org/Exceptions/Main.java

@@ -1,7 +1,148 @@
+
 package org.Exceptions;
+import org.FileExamples.AddresesingModes.FileAddressing;
+import org.FileExamples.CreatingFiles.CreateFileExample01;
+import org.FileExamples.CreatingFiles.CreateFileExample02;
+import org.FileExamples.DeletingFiles.DeleteFileExample01;
+import org.FileExamples.DeletingFiles.DeleteFileExample02;
+import org.FileExamples.ParsingJson.ParsingJsonExample01;
+import org.FileExamples.ReadingFiles.ReadFileExample01;
+import org.FileExamples.ReadingFiles.ReadFileExample02;
+import org.FileExamples.WritingFiles.WriteFileExample01;
+import org.FileExamples.WritingFiles.WriteFileExample02;
+import java.util.Scanner;
+
+/**
+ *
+ *
+ * @author Hesam Ghazi
+ * Student Number: 403222015
+ * @version 1.0
+ */
 
 public class Main {
-    public static void main(String[] args) {
+     static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        boolean exit = false;
 
+        System.out.println("=====================================");
+        System.out.println("  Java Exceptions & File Handling");
+        System.out.println("         Workshop Demo");
+        System.out.println("=====================================\n");
+
+        while (!exit) {
+            System.out.println("Select an option:");
+            System.out.println("1. Run Exception Handling Demo (FileService)");
+            System.out.println("2. Run RuntimeException Demo");
+            System.out.println("3. File Addressing Demo");
+            System.out.println("4. Create File Examples");
+            System.out.println("5. Delete File Examples");
+            System.out.println("6. Read File Examples");
+            System.out.println("7. Write File Examples");
+            System.out.println("8. Parse JSON Example");
+            System.out.println("9. Exit");
+            System.out.print("\nEnter your choice (1-9): ");
+
+            try {
+                // Using nextLine() and parsing prevents scanner buffer bugs
+                String input = scanner.nextLine().trim();
+                int choice = Integer.parseInt(input);
+
+                System.out.println("\n-------------------------------------");
+
+                switch (choice) {
+                    case 1:
+                        System.out.println("Running FileService Demo...\n");
+                        try {
+                            FileService.main(new String[]{});
+                        } catch (Exception e) {
+                            System.err.println("Error in FileService: " + e.getMessage());
+                        }
+                        break;
+
+                    case 2:
+                        System.out.println("Running RuntimeException Demo...\n");
+                        try {
+                            RuntimeExceptionDemo.main(new String[]{});
+                        } catch (Exception e) {
+                            System.err.println("Expected exception caught: " + e.getClass().getSimpleName());
+                            System.err.println("Message: " + e.getMessage());
+                        }
+                        break;
+
+                    case 3:
+                        System.out.println("Running File Addressing Demo...\n");
+                        try {
+                            FileAddressing.main();
+                        } catch (Exception e) {
+                            System.err.println("Error: " + e.getMessage());
+                        }
+                        break;
+
+                    case 4:
+                        System.out.println("Running Create File Examples...\n");
+                        System.out.println("Example 1 (File class):");
+                        CreateFileExample01.main();
+                        System.out.println("\nExample 2 (Files class):");
+                        CreateFileExample02.main(new String[]{});
+                        break;
+
+                    case 5:
+                        System.out.println("Running Delete File Examples...\n");
+                        System.out.println("Example 1 (File class):");
+                        DeleteFileExample01.main();
+                        System.out.println("\nExample 2 (Files class):");
+                        DeleteFileExample02.main();
+                        break;
+
+                    case 6:
+                        System.out.println("Running Read File Examples...\n");
+                        System.out.println("Example 1 (Scanner):");
+                        ReadFileExample01.main();
+                        System.out.println("\nExample 2 (Files.readAllLines):");
+                        ReadFileExample02.main();
+                        break;
+
+                    case 7:
+                        System.out.println("Running Write File Examples...\n");
+                        System.out.println("Example 1 (FileWriter):");
+                        WriteFileExample01.main();
+                        System.out.println("\nExample 2 (Files.write):");
+                        WriteFileExample02.main();
+                        break;
+
+                    case 8:
+                        System.out.println("Running Parse JSON Example...\n");
+                        try {
+                            ParsingJsonExample01.main();
+                        } catch (Exception e) {
+                            System.err.println("Error parsing JSON: " + e.getMessage());
+                            System.err.println("Make sure data.json is in the correct location.");
+                        }
+                        break;
+
+                    case 9:
+                        System.out.println("Exiting... Goodbye!");
+                        exit = true;
+                        break;
+
+                    default:
+                        System.out.println("Invalid choice. Please enter a number between 1 and 9.");
+                        break;
+                }
+
+                if (!exit) {
+                    System.out.println("-------------------------------------\n");
+                    System.out.print("Press Enter to continue...");
+                    scanner.nextLine();
+                }
+
+            } catch (NumberFormatException e) {
+                System.err.println("Invalid input. Please enter a valid menu number.");
+                System.out.println("-------------------------------------\n");
+            }
+        }
+
+        scanner.close();
     }
-}
+}

src/main/java/org/Exceptions/RuntimeExceptionDemo.java

@@ -8,20 +8,47 @@ public class RuntimeExceptionDemo {
         UserEntity user = new UserEntity("Ali", "Ahmadi", 1234567890L,
                 null, 989111111111L, null);
 
-        validateEmail(user);
-        calculatePayment(5000, 0);
-        convertUserAge("twenty");
-        completeRegistration(user);
+        // 1. Handle NullPointerException / IllegalArgumentException
+        try {
+            validateEmail(user);
+        } catch (NullPointerException e) {
+            System.err.println("Caught NullPointerException: Email string cannot be null.");
+        } catch (IllegalArgumentException e) {
+            System.err.println("Caught IllegalArgumentException: " + e.getMessage());
+        }
 
+        // 2. Handle ArithmeticException
+        try {
+            calculatePayment(5000, 0);
+        } catch (ArithmeticException e) {
+            System.err.println("Caught ArithmeticException: Cannot divide payment by zero installments.");
+        }
+
+        // 3. Handle NumberFormatException
+        try {
+            convertUserAge("twenty");
+        } catch (NumberFormatException e) {
+            System.err.println("Caught NumberFormatException: Could not parse invalid age string.");
+        }
+
+        // 4. Handle IllegalStateException
+        try {
+            completeRegistration(user);
+        } catch (IllegalStateException e) {
+            System.err.println("Caught IllegalStateException: " + e.getMessage());
+        }
+
+        System.out.println("\nRuntimeExceptionDemo executed completely and safely!");
     }
 
-
-    //nullPointerException
-    //IllegalArgumentException
     public static void validateEmail(UserEntity user) {
-
         String email = user.getEmail();
 
+        // Fix to prevent immediate NullPointerException before regex matching
+        if (email == null) {
+            throw new NullPointerException("Email cannot be null");
+        }
+
         String emailRegex = "^[A-Za-z0-9+_.-]+@[A-Za-z0-9.-]+$";
 
         if (!Pattern.matches(emailRegex, email)) {
@@ -31,32 +58,22 @@ public class RuntimeExceptionDemo {
         System.out.println("User email is valid");
     }
 
-    // ArithmeticException
     public static void calculatePayment(int totalAmount, int installmentCount) {
-
         int payment = totalAmount / installmentCount;
-
         System.out.println("Each installment : " + payment);
     }
 
-    // NumberFormatException
     public static void convertUserAge(String ageInput) {
-
         int age = Integer.parseInt(ageInput);
-
         System.out.println("User age: " + age);
     }
 
-//    IllegalStateException
     public static void completeRegistration(UserEntity user) {
-
         if (user.getDateOfBirth() == null) {
             throw new IllegalStateException(
                     "Registration cannot be completed. Date of birth is missing."
             );
         }
-
         System.out.println("Registration completed");
     }
-
 }

src/main/java/org/FileExamples/AddresesingModes/FileAddressing.java

@@ -5,7 +5,7 @@ import java.nio.file.Path;
 import java.util.Scanner;
 
 public class FileAddressing {
-    static void main() {
+    public static void main() {
         //relative
         Path relativePath = Path.of("data.txt");
         //absolute

src/main/java/org/FileExamples/CreatingFiles/CreateFileExample01.java

@@ -4,7 +4,7 @@ import java.io.File;
 import java.io.IOException;
 
 public class CreateFileExample01 {
-    static void main() {
+    public static void main() {
         File file = new File("texts/examples.txt");
         try
         {

src/main/java/org/FileExamples/DeletingFiles/DeleteFileExample01.java

@@ -3,7 +3,7 @@ package org.FileExamples.DeletingFiles;
 import java.io.File;
 
 public class DeleteFileExample01 {
-    static void main() {
+    public static void main() {
         File file = new File("example.txt");
 
         if (file.delete()) {

src/main/java/org/FileExamples/DeletingFiles/DeleteFileExample02.java

@@ -5,7 +5,7 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 
 public class DeleteFileExample02 {
-    static void main() {
+    public static void main() {
         try
         {
             Path path = Path.of("example.txt");

src/main/java/org/FileExamples/ParsingJson/ParsingJsonExample01.java

@@ -12,7 +12,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class ParsingJsonExample01 {
-    static void main() {
+    public static void main() {
 
         try {
             Path path = Path.of("data.json");

src/main/java/org/FileExamples/ReadingFiles/ReadFileExample01.java

@@ -5,7 +5,7 @@ import java.io.FileNotFoundException;
 import java.util.Scanner;
 
 public class ReadFileExample01 {
-    static void main() {
+    public static void main() {
         File file = new File("quotes.txt");
         try {
             Scanner reader = new Scanner(file);

src/main/java/org/FileExamples/ReadingFiles/ReadFileExample02.java

@@ -6,7 +6,7 @@ import java.nio.file.Path;
 import java.util.List;
 
 public class ReadFileExample02 {
-    static void main() {
+    public static void main() {
         Path path = Path.of("quotes.txt");
         try {
             List<String> lines = Files.readAllLines(path);

src/main/java/org/FileExamples/WritingFiles/WriteFileExample01.java

@@ -4,7 +4,7 @@ import java.io.FileWriter;
 import java.io.IOException;
 
 public class WriteFileExample01 {
-    static void main() {
+    public static void main() {
 
         try
         {

src/main/java/org/FileExamples/WritingFiles/WriteFileExample02.java

@@ -10,7 +10,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class WriteFileExample02 {
-    static void main() {
+    public static void main() {
         List<String> lines = List.of(
           "Line 1",
           "Line 2"