Implement user registration and login functionality

MailSystem/src/domain/User.java

@@ -0,0 +1,54 @@
+package domain;
+
+import java.time.LocalDate;
+
+public class User {
+
+	private static int counter = 1000;
+	private int userID;
+	private String firstname;
+	private String lastname;
+	private LocalDate birthdate;
+	private UserEmail usermail;
+
+	public User(String firstname, String lastname, LocalDate birthdate,String nutzername, char[] password) {
+		this.userID = counter++;
+		this.firstname = firstname;
+		this.lastname = firstname;
+		this.birthdate = birthdate;
+		this.usermail = new UserEmail(nutzername,password);
+	}
+
+	public String getFirstname() {
+		return firstname;
+	}
+
+	public void setFirstname(String firstname) {
+		this.firstname = firstname;
+	}
+
+	public String getLastname() {
+		return lastname;
+	}
+
+	public void setLastname(String lastname) {
+		this.lastname = lastname;
+	}
+
+	public LocalDate getBirthdate() {
+		return birthdate;
+	}
+
+	public void setBirthdate(LocalDate birthdate) {
+		this.birthdate = birthdate;
+	}
+
+	public int getUserID() {
+		return userID;
+	}
+
+	public UserEmail getUsermail() {
+		return usermail;
+	}
+
+}

MailSystem/src/domain/UserEmail.java

@@ -0,0 +1,32 @@
+package domain;
+
+public class UserEmail {
+
+	private static int counter = 1000;
+	private int accountID;
+	private String username;
+	private char[] password;
+	
+	public UserEmail(String username, char[] password) {
+		this.username = username;
+		this.password = password;
+		this.accountID = counter++;
+	}
+
+	public String getUsername() {
+		return username;
+	}
+
+	public  char[] getPassword() {
+		return password;
+	}
+
+	public void setPassword(char[] password) {
+		this.password = password;
+	}
+
+	public int getAccountID() {
+		return accountID;
+	}
+	
+}

MailSystem/src/domain/UserManager.java

@@ -0,0 +1,86 @@
+package domain;
+
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import domain.exception.UserAlreadyExistsException;
+
+public class UserManager {
+
+    private ArrayList<User> users;
+
+    public UserManager() {
+        this.users = new ArrayList<>();
+    }
+
+    public boolean addUser(String firstName, String lastName, String username,
+                           int year, int day, String monthName,
+                           char[] password, char[] passwordConfirmation) throws Exception {
+
+        if (firstName == null || lastName == null || username == null || password == null || passwordConfirmation == null) {
+            throw new IllegalArgumentException("No input should be null!");
+        }
+
+        if (firstName.trim().isEmpty() || lastName.trim().isEmpty() || username.trim().isEmpty() ||
+            password.length == 0 || passwordConfirmation.length == 0) {
+            throw new IllegalArgumentException("All fields are required!");
+        }
+
+        if (!Arrays.equals(password, passwordConfirmation)) 
+            throw new IllegalArgumentException("Passwords do not match!");
+
+        String email = username + "@easymail.de";
+
+        for (User tempUser : users) 
+            if (tempUser.getUsermail().getUsername().equalsIgnoreCase(email)) 
+                throw new UserAlreadyExistsException("This email address is already taken!");
+
+        int month = getMonthNumber(monthName);
+        if (month == 0) 
+            throw new IllegalArgumentException("Invalid month name: " + monthName);
+
+        LocalDate birthDate = LocalDate.of(year, month, day);
+        char[] passwordCopy = Arrays.copyOf(password, password.length);
+        User newUser = new User(firstName, lastName, birthDate, email, passwordCopy);
+
+        users.add(newUser);
+
+        Arrays.fill(password, ' ');
+        Arrays.fill(passwordConfirmation, ' ');
+        return true;
+    }
+
+    public boolean checkLogin(String username, char[] password) {
+        if (username == null || password == null) return false;
+
+        for (User user : users) 
+            if (user.getUsermail().getUsername().equalsIgnoreCase(username)
+                && Arrays.equals(user.getUsermail().getPassword(), password)) {
+                Arrays.fill(password, ' ');
+                return true;
+            }
+        Arrays.fill(password, ' ');
+        return false;
+    }
+
+
+    private int getMonthNumber(String txtMonth) {
+        switch (txtMonth.toLowerCase()) {
+            case "januar": return 1;
+            case "februar": return 2;
+            case "märz": return 3;
+            case "april": return 4;
+            case "mai": return 5;
+            case "juni": return 6;
+            case "juli": return 7;
+            case "august": return 8;
+            case "september": return 9;
+            case "oktober": return 10;
+            case "november": return 11;
+            case "dezember": return 12;
+            default: return 0;
+        }
+    }
+}
+

MailSystem/src/domain/exception/UserAlreadyExistsException.java

@@ -0,0 +1,7 @@
+package domain.exception;
+
+public class UserAlreadyExistsException extends Exception {
+	public UserAlreadyExistsException(String msg) {
+		super(msg);
+	}
+}

MailSystem/src/domain/unitTest/AddUserTest.java

@@ -0,0 +1,75 @@
+package domain.unitTest;
+import static org.junit.Assert.*;
+import static org.junit.Assert.assertThrows;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import domain.UserManager;
+
+class AddUserTest {
+    private UserManager userManager;
+
+    @BeforeEach
+    void setUp() {
+        userManager = new UserManager();
+    }
+
+    @Test
+    void testLeererVorname() {
+        Exception ex = assertThrows(Exception.class, () -> {
+            userManager.addUser("", "Test","nutzer", 2000, 1, "Januar", new char[]{'1'}, new char[]{'1'});
+        });
+        assertEquals("Alle Felder sind erforderlich!", ex.getMessage());
+    }
+
+    @Test
+    void testLeererNachname() {
+        Exception ex = assertThrows(Exception.class, () -> {
+            userManager.addUser("Max", "","nutzer", 2000, 1, "Januar", new char[]{'1'}, new char[]{'1'});
+        });
+        assertEquals("Alle Felder sind erforderlich!", ex.getMessage());
+    }
+
+    @Test
+    void testLeererNutzername() {
+        Exception ex = assertThrows(Exception.class, () -> {
+            userManager.addUser("Max", "Mustermann","", 2000, 1, "Januar", new char[]{'1'}, new char[]{'1'});
+        });
+        assertEquals("Alle Felder sind erforderlich!", ex.getMessage());
+    }
+
+    @Test
+    void testLeeresPasswort() {
+        Exception ex = assertThrows(Exception.class, () -> {
+            userManager.addUser("Max", "Mustermann","nutzer",2000, 1, "Januar", new char[]{}, new char[]{});
+        });
+        assertEquals("Alle Felder sind erforderlich!", ex.getMessage());
+    }
+
+    @Test
+    void testPasswoerterUnterschiedlich() {
+        Exception ex = assertThrows(Exception.class, () -> {
+            userManager.addUser("Max", "Mustermann","nutzer",2000, 1, "Januar", new char[]{'1','2'}, new char[]{'1','3'});
+        });
+        assertEquals("Passwörter stimmen nicht überein!", ex.getMessage());
+    }
+
+    @Test
+    void testNutzernameBereitsVergeben() throws Exception {
+        // Ersten Nutzer hinzufügen
+        userManager.addUser("Max", "Mustermann","nutzer",2000, 1, "Januar" , new char[]{'1'}, new char[]{'1'});
+
+        // Zweiter Nutzer mit gleicher E-Mail
+        Exception ex = assertThrows(Exception.class, () -> {
+            userManager.addUser("Moritz", "Muster","nutzer", 2001, 2, "Februar",  new char[]{'1'}, new char[]{'1'});
+        });
+        assertEquals("Diese E-Mail-Adresse ist bereits vergeben!", ex.getMessage());
+    }
+
+    @Test
+    void testErfolgreichHinzufuegen() throws Exception {
+        boolean result = userManager.addUser("Anna", "Beispiel","anna",1995, 15, "Mai", new char[]{'1'}, new char[]{'1'});
+        assertTrue(result);
+    }
+}

MailSystem/src/domain/unitTest/CheckLoginTest.java

@@ -0,0 +1,34 @@
+package domain.unitTest;
+
+import static org.junit.Assert.*;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import domain.UserManager;
+
+class CheckLoginTest {
+    private UserManager userManager;
+
+    @BeforeEach
+    void setUp() throws Exception {
+        userManager = new UserManager();
+        char[] pw = {'1','2','3','4'};
+        userManager.addUser("Ali", "Test","ali.test",2000, 1, "Januar", pw, pw.clone());
+    }
+
+    @Test
+    void testLoginMitKorrektenDaten() {
+        assertTrue(userManager.checkLogin("ali.test@easymail.de", new char[]{'1','2','3','4'}));
+    }
+
+    @Test
+    void testLoginMitFalschemPasswort() {
+        assertFalse(userManager.checkLogin("ali.test@easymail.de", new char[]{'1','1','1','1'}));
+    }
+
+    @Test
+    void testLoginMitFalschemNutzername() {
+        assertFalse(userManager.checkLogin("nicht.vorhanden@easymail.de", new char[]{'1','2','3','4'}));
+    }
+}

MailSystem/src/module-info.java

@@ -5,4 +5,7 @@
  * 
  */
 module MailSystem {
+	requires java.desktop;
+	requires junit;
+	requires org.junit.jupiter.api;
 }