Added the required objects and wrote some code

Author: Madhavan7

src/main/java/UserRegLoginButton.java

@@ -0,0 +1,2 @@
+public class UserRegLoginButton {
+}

src/main/java/UserRegistrationUI.java

@@ -1,2 +1,19 @@
-public class UserRegistrationUI {
+import javax.swing.*;
+
+public class UserRegistrationUI implements UserRegistrationUseCase{
+    UserDatabase database = new UserDatabase();
+    void GetUserCredentials(){
+        JFrame RegisterFrame = new JFrame();
+        JPanel RegisterPanel = new JPanel();
+
+    }
+    @Override
+    public void registerUser(String username, String password, String email) {
+        if(database.userExists(username, password, email)){
+            System.out.println("The username or password is already in use, please try again");
+        }else{
+            database.createUser(username, password, email, "Basic");
+            System.out.println("Your account has been created, please verify to login");
+        }
+    }
 }

src/main/java/UserRegistrationUseCase.java

@@ -1,3 +1,3 @@
-public class UserRegistrationUseCase {
-
+public interface UserRegistrationUseCase {
+    void registerUser(String username, String password, String email);
 }

src/main/java/UserVerificationUI.java

@@ -0,0 +1,3 @@
+public class UserVerificationUI implements UserVerifier{
+
+}

src/main/java/UserVerifier.java

@@ -0,0 +1,3 @@
+public interface UserVerifier {
+    void verify(UserDatabase database, String username);
+}